Inorganic Chemistry of the Transition Elements, Volume 2 (Specialist Periodical Reports) (v. 2)

A Specialist Periodical Report Inorganic Chemistry of the Transition Elements Volume 2 A Review of the Literature Publ...

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A Specialist Periodical Report

Inorganic Chemistry of the Transition Elements Volume 2 A Review of the Literature Published between October 1971 and September 1972

Senior Reporter B. F. G. Johnson, University Chemical Laboratory, Cambridge University Re porters

R. Davis, Kingston Polytechnic C. D. Garner, Manchester University L. A. P. Kane-Maguire, University of Wales, Cardiff J. A. McCleverty, University of Shcffield

0 Copyright 1973

The Chemical Society Burlington House, London, W I V OBN

ISBN : 0 85186 51 0 0 Library of Congress Catalog Card No. 72-83458

Printed in Gt. Britain by Page Bros (Norwich) Ltd. Nurwich.

Preface The aim of this Specialist Periodical Report is to cover in a comprehensive way the chemistry of the transition metals including the lanthanides and actinides. It includes published data on the metal carbonyls but does not necessarily include results concerned with organometallic complexes or spectroscopic data which are published elsewhere. This, the second volume of the series, covers the period October 1971 to September 1972 and follows the layout previously adopted in Volume 1 with only a few minor variations (see List of Contents). Thus Chapter 1 contains an account of the Chemistry of the Early Transition Metals excluding Scandium, Yttrium, and the Lanthanides. The Chemistry of the Elements of the first transition series Manganese to Copper is discussed in Chapter 2. Chapter 3 deals with the Noble Metals (Ru, Os, Rh, Ir, Pd, Pt, Ag, and Au) and Chapter 4 the Lanthanides (including Sc,,Y, and La) and Actinides. It is hoped that this volume will serve as a direct and convenient source of reference and informationover the whole range of the transition metals. We would have liked to have reported the data in a more critical way but given that the report is concerned with essentially preparative procedures and covers a vast amount of material scattered throughout the literature this is virtually impossible. Again we would emphasize that each of the Reporters would welcome constructive criticism and advice. B. F. G. Johnson

Contents Chapter 1 The Early Transition Metals By C.D. Garner 1 Titanium Introduction Binary Compounds and Related Species Oxides Halides and Oxyhalides Borides, Carbides, etc. Titanium(I1) Complexes Tit anium(rr1) Complexes N-Donor Ligands 0-Donor Ligands Halogeno-complexes Cyclopentadienyl Complexes Titanium(1v) Complexes N-Donor Ligands N- and 0-Donor Ligands P-Donor Ligands 0-Donor Ligands S-Donor Ligands Halogen- donor Ligands Organometallic Titanium(1v) Compounds Alkyl and Related Compounds Cyclopen tadienyl Derivatives 2 Zirconium and Hafnium Introduction Oxygen Compounds Oxides, Mixed Oxides, Zirconates, Hafnates, and their Hydrates Complexes with Oxyanion Ligands Complexes with 0-donor Ligands Sulphur, Selenium, and Tellurium Compounds Nitrogen Compounds

1 1 2 2 2 3 3 4 4

5 6 7 7 7 9 11 11 16 17 17 17 20

21 21 22 22 24 26 28 28

Contents

vi

Halogen Compounds Binary Compounds Fluoro-complexes Chloro-, Bromo, and Iodo-complexes Borides and Tetrahydroborate Compounds Carbon. Silicon, or Germanium Compounds Alkyl and Related Compounds Cyclopentadienyl Compounds

3 Vanadium Introduction Carbonyl. Cyanide, and Nitrosyl Complexes Simple Binary and Related Compounds Oxides Halides and Oxyhalides Sulphides and Selenides Nitrides and Phosphides Silicides and Germanides Hydrides Vanadium(11) Complexes Vanadium(tI1) Complexes 0-Donor Ligands S-Donor Ligands N-Donor Ligands Halogen-donor Ligands Organom e tall ic Con1plexes Vanadium(rv) Complexes 0-Donor Complexes Complexes with Oxygen and other Donor Atoms S- and Se-Donor Ligands N-Donor Ligands Complexes with Nitrogen and other Donor Atoms P-Donor Ligands Halogen- donor Ligands 0r gan o met a 11 i c C o 111 pl ex es Mixed-valence Oxide Compounds involving Vanadiu in(I v) Va na diu m(v) C o mpl exe s 0-Donor Ligands 0- and N-Donor Ligands S-, Se-. and Te-donor Ligands N -Donor Ligands Halogen-donor Ligands Organometal lic Com pou nds

29 29 29 30 30 31 31 31

33 33 34 36 36 37 37 37 38 38 38 38 38 40 40 40 40 40

41 45 47 48 48 49 49

49 50 51 51 57 57 57 58 58

vi i

Contents 4 Niobium and Tantalum Introduction Carbonyl Complexes Simple Binary and Related Compounds Oxides Halides and Oxyhalides Chalcogenides and their Intercalation Complexes Nitrides and Oxynitrides Arsenides Germanides and Silicides Borides H ydrides Metal Cluster Complexes Niobium(rrr) and Tantalum(m) Complexes Niobium(1v) and Tantalum(1v) Complexes Niobium(v) and Tantalum(v) Complexes 0-Donor Ligands S-, Se, and Te-donor Ligands 0-,or S-, and N-donor Ligands Halogeno-complexes N-Donor Ligands Organometallic Complexes

58 58 59 59 60 60 61 62 62 62 62 63 63 63 64

5 Chromium

76 76 76 78 79 80 85 85 87 89 90 92 92 92 93 93 93 93 94 94 95

Introduction Carbonyl Complexes Halogeno-complexes 0-,S-, and Se-donor Ligands N-, P-, As-, and Sb-donor Ligands Si-, Ge-, and Sn-donor Ligands Carbene Complexes Arene Carbonyl Complexes Bis-x-arene Complexes Dinitrogen, Nitrosyl, and Isocyanide Complexes Binary Systems Halides Oxides, Sulphides, and Tellurides Nitrides, Phosphides, and Arsenides Silicides and Germanides Borides Chromium(r1) Complexes Chromium(rrr) Complexes Halogeno-complexcs 0-Donor Ligands S- and Se-Donor Ligands

66 66 70 70 70

75 75

99

...

Cont en ts

Vlll

N-Donor Ligands P-Donor Ligands Complexes involving a Variety of Donor Ligands Organometallic Complexes Chromiurn(rv) Complexes Chromium(v) Complexes Chromium(v1) Complexes Oxyhalide Complexes 0 - D o n o r Ligands N-Donor Ligands

6 Molybdenum and Tungsten Introduction Carbonyl Complexes Halogeno-complexes 0-,S-. and Se-donor Ligands N-, P-, As-, and Sb-donor Ligands Carbene Complexes Complexes with Carbon, Silicon, Germanium, and Tin Complexes with Aluminium and Indium Dinitrogen, Nitrosyl. Isocyanide, and Cyanide Complexes H ydrido-complexes Binary Systems and Related Compounds Halides Oxides and Chalcogonides Phosphides Borides o r W-W Bonds Compounds with M-Mo Molybdenum(r1r) and Tungsten( 111) Complexes Molybdenum(1v) and Tungsten(1v) Complexes hlolvbdenum(v) and Tungstedv) Complexes Oxide and Oxyhalide Complexes 0-,S-, or Se-donor Ligands 0- and N-Donor Ligands N-, P-, or As-donor Ligands Molybdenum and Tungsten Bronzes Molybdenum(v1) and Tungsten(vr) Complexes 0 - D o n o r Ligands S-. Se-. and Te-donor Ligands N-Donor Ligands Halogefi- donor Ligands Complexes with Tungsten-Carbon o-Bonds

100 102 102 106 107 108 108 108 108 111

111 111 112 114 114 117 127 128 131 131 135 136 136 136 137 137 137 139 140 144 144 145 146 146 147 147 147 157 158 158 162

ix

Contents 7 Technetium and Rhenium Introduction Carbonyl Complexes Halogeno-complexes 0- or S-Donor Ligands N-, P-, As-, or Sb-donor Ligands Si-Donor Ligands Dinitrogen, Isocyanide, and Nitrile Complexes Hydrido-complexes Rhenium(1r) Complexes Rhenium(1rr) Complexes Technetium(1v) and Rhenium(1v) Complexes Technetium(v) and Rhenium(v) Complexes Technetium(v1) and Rhenium(v1) Complexes Technetium(vr1) and Rhenium(vr1) Complexes 8 Appendix

162 162 163 01 65

165 166 167 167 168 169 169 171 173 175 176 177

Chapter 2 Elements of the First Transitional Period By R. Davis 1 Introduction

179

2 Manganese Carbonyl Compounds Nitrogenyl and Nitrosyl Compounds Other Manganese (I) Complexes Manganese (11) Halides and Pseudohalides Complexes N-Donor ligands 0-Donor ligands S-Donor ligands Mixed donor ligands Oxides and Sulphides Manganese(Ir1) Halides Cyano-compounds Complexes Higher Oxidation States of Manganese

179 179 187 188 188 188 189 189 190 192 192 193 194 194 194 194 195

3 Iron Carbonyl Compounds Carbonyl Carbides Carbonyl Halides and Hydrides

196 196 197 197

Contents

X

Anionic and Cationic Carbonyls Mixed Metal Complexes Germanium and Tin Ligands N-Donor Ligands Other Group VA Donor Ligands Group V 1A Donor Ligands SOz Insertion Reactions Reactions of Co-ordinated CO and Lewis Acid Adducts Other Compounds Nitrogenyl and Nitrosyl Compounds Other Iron(0) Compounds Iron(1r) Halides and Pseudohalides Hydrides Complexes Pyridine and related ligands Imidazole and pyrazole ligands Macrocyclic N-donor ligands Other N-donor ligands 0-donor ligands S- and P-donor ligands Mixed donor ligands Isonitrile and other complexes I ro n (111) Halides and Pseudohalides Complexes N-Donor ligands 0-Donor ligands S-Donor ligands Mixed donor ligands Iron(rv) Other Iron Compounds of Biological Interest Oxides and Hydroxides 4 Cobalt

Carbonyl Compounds Anionic Complexes Group IVA Donor Ligands Group VA Donor Ligands Group VIA Donor Ligands Other Complexes Reactions of Co-ordinated CO Nitrosyl Compounds Cobalt(1)

198 198 200 202 204 207 210 210 21 1 21 1 214 214 214 215 215 217 217 219 219 220 220 22 1 222 222 223 223 224 226 227 228 228 229 229 229 230 230 23 1 23 1 232 233 234 236

xi

Contents

Cobalt(I1) Halides and Pseudohalides Complexes Amine complexes Pyridine and related ligands Imidazole, pyrazole, and related ligands Macrocyclic N-donor ligands Other N-donor ligands 0-Donor ligands S- and Se-donor ligands P-Donor l'igands Mixed donor ligands Other Compounds Cobalt(m) Complexes Amrnine complexes Diamine complexes Tri- and tetra-amine complexes Macrocyclic N-donor ligands and vitamin B,, analogues Oximato-complexes Other N-Donor ligands 0-Donor ligands S-Donor ligands Amino-acid complexes Schiff-base ligands Other mixed donor ligands Polynuclear anion-bridged complexes Other Compounds Cobal t-Oxygen Compounds Oxides Other Compounds 5 Nickel Carbonyl, Nitrosyl, and Nitrogenyl Compounds Halides and Pseudohalides Nickel (0) Nickel(1) Nickel(I1) Complexes Pyridine and related ligands Amine and related complexes Imidazole and pyrazole ligands Macrocyclic N-donor ligands Other N-donor ligands

236 236 237 237 237 240 240 242 243 245 246 247 252 252 252 252 254 256 257 260 263 264 265 266 268 269 270 272 273 275 275

275 275 277 277 28 1 28 1 28 1 282 283 286 286 294

Contents

xii 0-Donor ligands S- and Se-donor ligands P- and As-donor ligands Mixed donor ligands Other Compounds Nickel(II1) and Nickel(1v) Oxides and Sulphides

295 298 30 1 303 313 313 314

6 Copper coppem Halides and Cyanides Complexes N-Donor ligands 0-.S-, and Se-donor ligands P-Donor ligands Mixed donor ligands Copper(1r) Halides Complexes N-Donor ligands 0-and S-donor ligands Mixed donor ligands Copper(111) Oxides Physical Measurements on Copper Complexes

314 314 314 315 315 315 316 317 318 318 318 318 322 324 328 329 329

7 Ligands

335

8 Formation and Stability Constants

340

Chapter 3 The Nobel Metals By 1.A. P. Kane- Maguire 1 Ruthenium Cluster Compounds Ruthenium-(0) and -(I) Ruthenium(11) Group VII Donors Halide donor ligands Halogeno-carboilyl and -phosphine complexes Hydrido-carboilyl and -phosphine complexes Group VI Donors Oxygen dopor ligands Su1p hu r donor 1iga ,ids

347 347 350 351 351 351 352 353 353 353 355

...

Contents

Xlll

Group V Donors Molecular nitrogen complexes Nitrosyl complexes Other nitrogen donor ligands Phosphorus, arsenic, and antimony donor ligands Group IV Donors Carbon donor ligands Silicon, germanium, and tin donor ligands Group 111 Donors Boron donor ligands Ruthenium(Ir1) Group VII Donors Group VI Donors Oxygen donor ligands Sulphur donor ligands Group V Donors Nitrogen donor ligands Phosphorus and arsenic ligands Group IV Donors Ruthenium(1v) Ruthenium(v) and Higher Oxidation States 2 Osmium

Cluster Compounds Osmium-(0) and -(I) Osmium(1r) Group VII Donor Ligands Halogeno-phosphine complexes Hydrido-carbonyl and -phosphine complexes Group V Donor Ligands Molecular nitrogen complexes Nitrosyl complexes Other nitrogen donor ligands P-Donor ligands Group IV Donors Osmium(Ir1) Osmium(I v) Group VII Donors Group VI and V Donors Osmium(v) Osmium(v1) Osmium(vIII)

3 Rhodium Cluster Compounds Rhodium(1)

355 355 356 358 361 362 362 362 363 363 363 363 364 364 364 365 365 366 366 366 3 68 368 368 370 370 370 370 370 370 370 37 1 371 371 372 372 372 3 72 3 72 373 373 373 374 374 375

Contents

xiv

Group VII Donors Halogeno-carbonyl and -phosphine complexes Group VI Donors Oxygen donor ligands Molecular oxygen adducts Group V Donors Nitrosyl complexes Other nitrogen donor ligands Phosphorus donor ligands Group IV Donors Rhodium(11) Rhodium(II1) Group VII Donors H ydrido-complexes Halogeno-carbonyl and -phosphine complexes Group VI Donors Oxygen donor ligands Sulphur donor ligands Group V Donors Nitrogen donor ligands 4 Iridium Iridium(0) I ridi um( I) Group VII Donors Hydrido-carbonyl and -phosphite complexes Halogeno-carbonyl and -phosphine complexes Group VI Donors Oxygen and sulphur donor ligands Group V Donors Nitrogen donor ligands Phosphorus donor ligands Group IV Docors Iridium(I1r) Group VII Donors Halogeno-carbonyl and -phosphine complexes Hydrido-carbonyl and -phosphine complexes Group VI Donors Oxygen and sulphur donor ligands Group V Donors Nitrogen donor ligands Phosphorus and arsenic ligands Group IV Donors Iridium(IV) Group VII Donors Iridium (Y )

375 375 378 378 378 379 379 379 380 38 1 382 383 383 383 383 384 384 385 386 386 390 390 390 390 390 39 1 393 393 394 394 394 395 396 396 396 396 397 397 39 8 398 399 400 40 1 40 1 403

XV

Contents

5 Palladium Palladium(0) Palladium(1) Palladium(rr) Group VII Donors Halide donor ligands Halogeno-carbonyl and -phosphine complexes Group VI Donors Oxygen and mixed oxygen-nitrogen donor ligands Sulphur donor ligands Group V Donors Nitrogen donor ligands Phosphorus and arsenic donor ligands Group IV Donors Palladium(1v) 6 Platinum Cluster Compounds Platinum(0) Group VI Donors Group V Donors P- and As- donor ligands Group IV Donors Platinum(1) Platinurn(~) Group VII Donors Halogeno-complexes Hydridophosphine complexes Halogenophosphine complexes Group VI Donors Group V Donors N-donor ligands P- and As-donor ligands Group IV Donors C- donor ligands Si-, Ge-, and Sn-donor ligands Platinum(II1) Platinum(1v) Group VII Donors Group VI Donors Group V Donors N-donor ligands P- donor ligands 7 Silver Silver(1) Group VII Donors

403 403 404 404 405 405 40 5 405 405 407 410 410 41 2 414 419 41 9 419 419 419 420 420 42 1 422 42 2 422 422

422 423 424 42 7 42 7 43 1 432 432 433 434 434 434 434 434 434 437 440 440 440

Contents

xvi Group VI Donors 0-donor ligands S- and Se-donor ligands Group V Donors Silver(I1) Group VII Donors Group VI Donors

8 Gold G 01 d(0) Gold(1) Gold(11) Gold(m) Group VII Donors Group VI Donors Group V Donors

440 440 44 1 441 442 442 442 445 445 445 446 446 446 446 447

Chapter 4 The Lanthanides, including Scandium and Yttrium, and the Actinides By J. A. McCleverty 1 Scandium and Yttrium

45 1

2 The Lanthanides

452

Lanthanide Shift Reagents General Chemistry of the Lanthanides

452 45 5

3 The Actinides The General Chemistry of Actinide Elements Uranyl and Neptunyl Compounds

470

Author Index

473

462 462

The Early Transition Metals BY

c. D . GARNER

1 Titanium

Introduction.-The majority of investigations reported this year have been concerned with Ti'v-oxygen compounds, although the pale green pyroxene NaTiSi,O, has been shown' to be one of the few known oxides containing Ti111. Trigonal-bipyramidal geometry for Ti"' has been confirmed2 in TiBr,,2NMe3, with the bulky amine ligands in the axial positions. Five-coordinate Ti'" in [Cl,Ti(PhCOCH,COMe)] is consistent with i.r. spectral and molecular weight studies; however, since 'H n.m.r. spectra indicate two distinct P-diketone complexes, the solution equilibrium 2[TiC13(bzac)] -; [Ti(bzac),Cl,]

+ TiCl,

is suggested. This receives some confirmation from the crystal structure of [TiCl,(acac)], which has shown that in the solid state the compound is a centrosymmetric chloride-bridged dimer.3 Studies of titanium tetra-alkyls have been featured in the recent interesting developments of transition metal-alkyl chemistry. Thus tetra-ne~pentyl-~ and -1-norbornyl-titanium5 have been isolated. A low-temperature crystal structure determination of tetrabenzyltitanium has identified an average Ti-C-C interbond angle of 103", which contrasts with the corresponding value of 111" for tetrabenzyltin, suggesting a weak overlap between the n-ring system and the empty metal &orbitals in the former compound.6 Tetracyclopen t adienyltit anium contains two h - and two h '-cyclopen tadienyl rings, and solution n.m.r. studies above 250 K have characterized the first known interchange of hs- and h'-rings.' The involvement of titanocene and related species in the reduction of dinitrogen has been further investigated,

' C. T. Prewitt, R. D . Shannon, and W. B. White, Contrib. Mineral. Petrology, 1972, 35, 77. ' '

P. T. Greene, B. J. Russ, and J. S. Wood, J . Chem. SOC.( A ) , 1971, 3636. (a) D. W. Thompson, R. W. Rosser, and P. B. Barrett, Inorg. Nuclear Chem. Letters, 1971,7,931; (b) N. Serpone, D. G . Bickley, P. H. Bird, and D . W. Thompson, J.C.S. Chem. Comm., 1972,217. W. Mowat and G. Wilkinson, J . Organometallic Chem.. 1972,38, C35. B. K. Bower and H. G. Tennent, J . Amer. Chem. SOC.,1972,94,2512. G. R. Davies, J. A. J. Jarvis, and B. T. Kilbourn, Chem. Comm., 1971, 151 1. (a) F. A. Cotton, J. L. Calderon, and J. Takats, J . Amer. Chem. SOC.,1971, 93, 3587; (b) F. A. Cotton, J. L. Calderon, B. G . DeBoer, and J. Takats, ibid., p. 3592; ( c ) E. M. Brainina, N. P. Gambaryan, B. V. Lokshin, P. V. Petrovskii, and Yu.T. Struchkov, Izvest. Akad. Nauk S.S.S.R.. Ser. khim., 1972, 187.

1

Inorganic Chemistry of the Transition Elements

2

and the dinuclear complexes ([(C,H5),PriTi,N,]}s and ([(C5R5),Ti2N,])' (R = H or Me) have been isolated. The latter are believedgbto involve bridging dinitrogen co-ordinated edge-on between the two titanium centres, (1).

Binary Compounds and Related Species.-Oxides. The dissociation energies of gaseous T i 0 and TiO, have been estimated as 600 21 and 660 -+_ 19 kJ mol- ', and 1200 & 42 and 1300 & 12 kJ mol- ', respectively." The physical properties of liquid TiO, have been investigated to 2600 K." Further studies of members of the homologous series Tino,,,- have been reported. y-Ti,O, has been obtained by heating a mixture of TiO, and T i 2 0 3(1:1; 900-925 "C; 1 month) and shown to have a V,O,-type structure.', Crystals of Ti,O, involve TiO, octahedra (Ti-0 = 200.4-202.2 pm) sharing faces, edges, and c0rne1-s.~~ The heat and entropy were determined electrochemically as -680 kJ mol-' and 173 e.u.. re~pectively.'~ Halides and Oxyhulides. Molecules of TiCl,, prepared by the Knudsen cell technique, have been isolated in solid inert-gas matrices. The i.r. spectrum (33-1000 cm- ') suggests that the molecules are linear ( & 10"); however, similar studies indicated that TiF, molecules are bent.' TiC1, with high catalytic activity has been prepared by the treatment of finely powdered T i 0 in a quartz tube with the stoicheiometric amount of gaseous CC1, at 400-700°C.16 Halogen-exchange reactions of BBr, with anhydrous TiCl, and TiCl,, and of BI, with anhydrous TIC],, which afford the corresponding anhydrous titanium bromides and iodides, are typical of the general reactions of boron halides with transition-metal chlorides. ' Borazines may be partially halogenated with TiX, (X = F or CI), which is reduced to TiX,.'* Raman spectra of A. E. Shilov, A. K. Shilova, E. F. Kvashina, and T. A. Vorontsova, Chern. Cornm., 1971, 1590. Klaentischi, and J. S. Miller, J.C.S. Chem. Comm., 1972,481 ; (b)J. E. Bercaw, R. H. Marvich, L. G . Bell, and H. H. Brintzinger, J . Amer. Chem. Soc., 1972,94, 1219; (c) A. Gaudener, Recherche, 1971, 2,475 l o G. Balducci, G . DeMaria, M. Guido, and V . Piacente, J . Chem. Phys., 1972, 56, 3422; H. Y. Wu and P. G . Wahlbeck, ibid., p. 4534. B. Mitin and'Yu. A. Nagibin, Izvest. Akad. Nauk S . S . S . R . . Neorg. Materialy, 1971, 7 , 814. G. Asbrink, S. Asbrink, A . Magneli, H. Okinaka, K. Kosuge, and S. Kachi, A c f a Chem. Scand., 1971, 25, 3889. l 3 M. Marezio and P. D. Dernier, J . Solid State Chem.. 1971, 3, 340. l 4 I. A. Vasil'eva, E. Yu. Shaulova, I . S. Sukhushina, and S. N. Shekhtman, Zhur.$z. Khim., 1971, 45, 2013. I s J . W. Hastie, R. H . Hauge, and J. L. Margrave, High Temp. Sci., 1971, 3, 257. l 6 V. Brozek, L. Mrnak, and V. Dufek, Czech. P., 138 155 C1.C.Olg) 1970. " P. M. Drum and M. F. Lappert, J . Chem. SOC.( , A ) , 1971. 3595 G . A. Anderson and J. J. Lagowski, Inorg Chem.. 1971,>0, 1910 (a) E. E. van Tamelen, W. Cretney, N .

The Early Transition Metals

3

TiF, have shown that it exists as tetrahedral monomeric molecules in the gas phase (300"C) but that the solid involves appreciable p01ymerization.l~Vapourphase Raman spectra have also been reported for TiX, (X = C1, Br, or I), and the Ti-X stretching force constants decrease in the order Ti-Cl > Ti-Br > Ti-I. This behaviour was also found for ZrX, and HfX, molecules and appears to be typical of halide complexes in this part of the Periodic Table.,' The 81Brn.q.r. spectra of TiBr, between 77 and 306 K suggest Br-Ti-Br interbond angles in the range 108.7-1 10.3", and that the ionic and double bond characteristics of the Ti-Br bond are cu. 60 and 16 %, respectively.21 The reaction of TiCl, with S b 2 0 3 or As203, or of TiOC1, with SnCl,, affords TiOCl.,, TiOBr has been prepared by the reaction of Ti with TiO, and Br, in a 650-550 "C temperature gradient. This latter compound exhibits weak temperature-independent paramagnetism, and involves Ti-0 and Ti-Br bonds of lengths 195.2 and 254.4 pm, re~pectively.,~ Borides, Carbides, etc. TiB, and the mixed diboride TiB,-ZrB, have been obtained,, by heating a stoicheiometric mixture of boron and the metal dioxides (1600-900°C; mmHg). TiW,B, and Ti,W,B, have been characterized by X-ray studies25 as has (Ti,Nb)B in the Ti-Nb-B system at 1 100-1800 0C.26 Crystalline, stoicheiometric TIC has been prepared, the crystal lattice constant being 432 0.06 The chemical stability of the germanides TiGe, TiGe,, and Ti,Ge3 towards mineral and organic acids, and oxidizing and complexing reagents has been studied,28 and the new compound Ti,Ge, has been prepared from the elements at high temperature^.^' The formation of TIN by a new method involving metal evaporation has been de~cribed.~' TiSe, has been isolated3' by passing selenium vapour in a stream of an inert gas, such as argon, over powdered titanium metal at 900--1200°C. The chalcogenide inclusion compound TiS,(MeCONH,) has been isolated.32 Titanium(i1) Complexes.-Very few investigations of this oxidation state have been reported this year. The electronic absorption spectrum of Ti" doped in CdTe has been reported,33and the hyperfine and super-hyperfine interactions of this ion in MF, (M = Ca, Sr, and Cd) lattices have been studied at 4.2 K.34 l9 2o

22 23 24

25

26 27

29

30 31

32 33 34

L. E. Alexander and I. R. Beattie, J . C. S. Dalton, 1972, 1745. R. J. H. Clark, B. K. Hunter, and D. M. Rippon, Znorg. Chem., 1972, 11,56; Chem. andlnd., 1971, 787. T. Okuda, Y. Furukaura, and H. Negita, Bull. Chem. SOC.Japan, 1971,44,2083. G. M. Toptygina and N. P. Dergacheva, Zhur. neorg. Khim., 1972, 17, 270. H. G. Von Schnering, M. Collin, and M. Hassheider, Z . anorg. Chem., 1972, 387, 137. R. Fairre and F. Thevenot, Bull. SOC. chim. France, 1971, 3911. Yu. B. Kuz'ma, S. I. Svarichevskaya, and V. S. Telegus, Porosh. Met., 1971, 11, 61. A. M. Zakharov, I. I. Novikov, and V. P. Pshokin, Zzvest. V. U.Z . Tsvet. Met., 1971, 14, 1 1 1. B. W. Davis and R. G . Varsanik, J . CoIloidZnterface Sci., 1971, 37, 870. R. S. Biryukova, V. N. Bondarev, and 0. I. Popova, Porosh. Met., 1971, 11,9. J. Hallais, Ann. Chim. (France), 1971,6, 321. A. Itoh, Denki Shikenjo Zho, 1970, 34, 877. V. A. Obolonchik and L. M. Prokoshina, Porosh. Met., 1971, 11, 31. F. R. Gamble, R. A. Klemm, and E. F. Ullmans, G. P., 2061 162 (Cl.C.Olg), 1971. P. A. Slodowy and J. M. Baranowski, Phys. Status Solidi (B), 1972, 49, 499. Yu.F. Mitrofanov, Yu. E. Pol'skii, and M. L. Falin, Zhur. eksp. teor. Fiz., 1971, 61, 1486.

4


The electrochemical oxidation of Ti” as Ti(AlCl,), in AlC1,-NaC1 melts (160-330°C) has been shown35 to proceed in two one-electron reversible steps, as Ti” = Ti”’ + Ti’”. A review has been presented of the nitrogen-fixation model which involves the co-ordination of dinitrogen to titanocene. followed by reduction with Na’ naphthalene- and hydrolysis. which effect the liberation of The bis(cyclopentadienyl)titanium(ii) species [(C,Me,),Ti], [(C,Me,),Ti],, and [(C5H5),Ti),, have been prepared and their reactions studied. These compounds react reversibly with molecular hydrogen to give hydride complexes, and with dinitrogen to form intensely coloured dinitrogen derivatives. The dinuclear species [(C,R,),TiN2Ti(C,R,)2] (R = H or Me) which have been prepared in this way are believed to have the structure (1). These bis(cyclopentadieny1)titanium(11) species react irreversibly with carbon monoxide to give the respective dicarbonyl derivatives. Triphenylphosphine undergoes a reversible reaction with [(C,Hs)2Ti]2 to give a compound of composition [(C,H,),TiPPh,],. This phosphine complex reacts reversibly with molecular hydrogen to give [(C5H,),Ti(PPh3)H], and irreversibly with dinitrogen and carbon m ~ n o x i d e . ’Related ~ studies have examined the titanocene-induced fixation of nitrogen in detail, and the reaction sequence given in Scheme 1 has been suggested.’” ‘ActiLe titanocene’. prepared by the use of t w o equivalents of sodium under argon for 6-10 days followed by filtration in a drybox, reacts rapidly and reversibly with N, below room temperature, forming a dark-blue complex. ‘Active titanocene’ is also believed to be a powerful hydrogenation catalyst .

[(X-CPKCjH,)TiH],

CH,=CHR

Titanium(iI1) Complexes.-N-Donor Ligands. A full account of the preparation and properties ofTi[N(SMe,),], has been p ~ b l i s h e d . Crystals ,~ ofTiBr,,2NMe3 consist of monomeric five-co-ordinate molecules which are basically trigonalbipyramidal, with average bond lengths Ti-Br = 242 pm and Ti -N = 232 35 36

K . W . Fung and G. Namantov, J . Electroanalyt. Chem. Interfacial Electrochem., 1972, 35, 27. E. C. Alyea, D. C. Bradley, and R. G. Copperthwaite, J . C.S. Dalton, 1972, 1580.


5

pm, and all Br-Ti-Br interbond angles ca. 120". It is suggested that in complexes of the type MX,(AMe,), (A = N or P) the steric requirements of the AMe, groups dictate the basic trigonal-bipyramidal geometry, these ligands occupying axial positions.2 Although the steric requirements of NN-bis-(6methyl-2-pyridy1methyi)methylamine (Me,dpma) would be expected to favour a five-co-ordinate complex with TiCl,, it forms the adduct (2) in which the metal atom has a distorted octahedral environment.

The three Ti-Cl bond lengths of 229.2(7), 236.4(6), and 241.8(7) pm are significantly different, and the Ti-tertiary nitrogen bond, 221.2(1.6) pm, is shorter than the Ti-aromatic nitrogen bonds, 225.6(1.6)pm (a~erage).,~ X-Band e.s.r. spectra of TiC1, in pyridine solution at room temperature and 77 K have provided evidence that the dimeric [TiCl,(py),], is the major complex species. It is suggested that this dimer consists of two trans-octahedral TiCl,(py), units linked by an edge of two bridging chlorides, the intermetallic separation being ca. 340 pm.,' TiCl,,MeCN has been prepared by heating TiC13.3MeCN at 100°C. Several mixed solvent adducts were also characterized in this study (see below).39At room temperature, TiCl, forms a 1 : 3 adduct with CH,ClCN, and the electronic spectrum of this royal blue compound suggests that it has a mer-octahedral s t r ~ c t u r e . ~ ' 0-Donor Iigunds. The pyroxene NaTiSi,O,, synthesized' at high pressure (65 kbar) and temperature (1550 "C), is obtained as light-green crystals when quenched to room temperature. X-Ray studies showed that the crystals are of the NaM"'Si,O, structural type, and the diffuse reflectance electronic spectrum confirmed that this is one of the few oxides known to contain Tiiii. Ti(H,PO,), has been prepared41 by treating titanium disilicide, TiSi,, with H,PO,. Thereactionofdiethylchlorophosphate,(EtO),P(O)Cl,with anhydrous TiC1, at elevated temperatures leads to de-ethylation of the phosphate and the precipitation of Ti(ethoxychlorophosphate),.42 37 38

39 O0 O1

O2

R. K. Collins, M. G. B. Drew, and J. Rodgers, J . C. S. Dalton, 1972, 899. S. G. Carr and T. D..Smith, J . C. S. Dalton, 1972, 1887. G. R. Hoff and C. H. Brubaker, jun., Inorg. Chem., 1971,10,2063. , G. W. A. Fowles, K. C. Moss, D. A. Rice, and N. Rolfe, J . C.S. Dalfon, 1972, 915. V. P. Kopylova and T. N. Nazarchuk, Porosh. Met., 1972, 12,46. C. M. Mikulski, N. M. Karayannis, and L. L. Pytlewski, J . Inorg. Nuclear Chem., 1972, 34, 1215.

6


The crystal structure of hexaureatitanium(1rr)perchlorate has been determined.43 The structural details of the cations, which involve a trigonally distorted octahedral TiO, unit (average Ti-0 = 204 pm), are very similar to those found for this ion in the iodide. A new method for the preparation of [Ti(acac),] has been reported. Treatment of TiC1, in toluene, in uucuo, with NH,(acac) for 4 h at room temperature eliminates any oxidation problems. The oxidation of [Ti(acac),] was also studied and the e.s.r. characteristics of the intermediate were determined.44 The proton and deuteron n.m.r. linewidths of [Ti(acac),] and other paramagnetic trisacetylacetonato-complexes and their deuteriated analogues have been measured. In agreement with theoretical predictions the deuteron spectra show significantly better resolution (cu. forty-fold), thus suggesting that useful information can be obtained from deuteron n.m.r. studies of paramagnetic complexes.4s E.s.r. spectra of Ti"' complexes with mandelic, malic. citric. cyclopentane- 1,2,3,4-tetracarboxylic. 5-sulpho-. 5-chloro-. and p-aminosalicylic, and phthalic acids, salicylamide, and 8-hydroxyquinoline in DMF solution have provided evidence for dimeric complexes. The magnetic properties of the Ti"' pairs have been evaluated and the distance between metal centres estimated to range from 470 pm for TiC1, (0.1 mol 1- I ) with mandelic acid (0.3 mol 1 - ') to 860 pm for TiCI, (0.1 mol 1- ') with 8-hydroxyquinoline (0.3 moll- 1).46 The reactions of TiCl, with several co-ordinating solvents have been studied, and the new complexes TiCI3,3L', TiC1,,LiL2 (where L' = dioxan and L2 = MeCN, THF, or PrOH), TiC13,2THF,MeCN, and Et4N[TiC1,,2L] (L = dioxan or THF) have been prepared and characterized by spectral and magnetic studies.39

Halogeno-complexes. (NH4)Zn[TiF6],6H20 has been prepared by adding [(NH4),TiFs] to warm aqueous hydrofluoric acid containing mossy zinc metal, followed by addition of NH,HF,. The electronic spectrum of this compound consists of maxima at 22 124 and 14 535 cm- :in aqueous solution the former maximum slowly shifts to 19608 cm-'. It is suggested that this splitting is too great for a Jahn-Teller effect and that the Ti"' is in a distorted ~ ' and P-modifications of Li,TiF, octahedral environment in this c ~ m p o u n d . 3have been prepared by treating LiF and TiF, ( 3 : l ) at elevated temperatures and then quenching or slowly cooling, respectively." TiCl, reacts with pyridinium chloride in hydrochloric acid solution to form a bright-green crystalline product (pyH),[TiCl,(H,O)J, which is stable in an oxygen-free dry atmosphere. The compound may be dehydrated by heating at 127 0C.49The general theory of magnetic exchange interaction between two atoms with orbitally degenerate wavefunctions has been applied to the inter43 44

45 46

*' 48

49

B. N. Figgis, L. G. B. Wadley, and J. Graham., Acta Cryst., 1972, B28, 187. G. Y . 4 . Lo and C. H. Brubacker, jun., J . Inorg. Nuclear Chem., 1972, 34, 2315. A. Johnson and G . W. Everett, jun., J . Amer. Chem. Soc., 1972,94, 1419. T. D. Smith, T. Lund, and J. R. Pilbrow, J . Chem. SOC.( A ) , 1971, 2786. L. Herman and G . Mitra, J . Fluorine Chem., 1972, 1,498. W. Massa and W. Rudorff, 2.Naturforsch., 1971, Xb, 1216. G. M . Toptygina and N. P. Dergacheva, Zhur. neorg. Khim., 1971, 16, 2889.

7


action of two Ti"' ions in the [Ti2Cl9I3- anion. Excellent agreement with the experimental magnetic susceptibility (90-300 K) was obtained. Cyclopentadienyl Complexes. Improved routes to [(n-Cp),TiCl], have been described, e.g. by reduction of [(n-Cp),TiCl,] in THF, with recrystallization from ether. This dimer reacts with L = NH,, RNH,, py, Me,PhP, or MePh,P to form [(n-Cp)TiClL], and with the bidentate ligands L, = bipy, en, or symMe,en, to form [(n-Cp),TiL,]+. With Ph,PCH,CH,PPh, a dinuclear complex is formed for which the structure (3) has been ~ u g g e s t e d . ~ ~

The complexes [(n-Cp)TiC12],2py and [(n-Cp)TiCl,],L, (L2 = bipy or a-picolylamine) have been prepared by allowing the appropriate N-heterocycle to react with [(n-Cp)TiCl,]. The spectroscopic, magnetic, and conductivity data obtained did not distinguish between dimeric or monomeric units for these complexes. [(n-Cp)TiCl,],l.Sen was also isolated in this study.52 The [(n-Cp)TiX,],THF (X = C1, Br, or I) complexes, prepared by reduction of [(n-Cp)TiX,] in THF, have been characterized as monomeric species involving a pseudo-tetrahedral stereochemistry about the central Ti"'. Pyrolysis of these T H F complexes results in loss of the solvent molecule.53. E.s.r. spectra have been obtained from frozen solutions of [(n-Cp),Ti(AR,),] (A = N, P, or As, n = 2; A = Ge or Sn, n = 3; R is typically Ph) and [(n-Cp)TiPbPh,], and trends in g-values and hyperfine splitting have been explained in terms of the electron-donor characteristics of the l i g a n d ~ . ~ ~ The unstable dinuclear complex [(IT-Cp),Pr'Ti], has been obtained from the reaction of [(n-Cp),TiCl] with Pr'MgC1 in ether under a nitrogen atmosphere at 193-173 K. An excess of the Grignard resulted in a slow transformation of this blue complex into a black derivative which quantitatively evolved hydrazine when treated with HC1.8

,

Titanium( IV) Complexes.-N-Donor Ligands. The oxidation of TiCl by the chlorinated alkyl cyanides CH,CICN, CHCl,CN, CCl,CN, and CH,ClCCl,CN C. G. Barraclough and A. K. Gregson, J . C. S. Faraday ZZ, 1972,68, 177. M. L. H. Green and C. R. Lucas, J . C. S. Dalton, 1972, 1000. " V. T. Kalinnikov, G. M. Larin, 0. D. Ubozhenko, A. A. Zharkikh, V. N. Latyaeva, and A. N. Lineva. Doklady Akad. Nauk S . S . S .R., 1971, 199, 95. 53 R.S . P.Coutts, R. L. Martin, and P. C. Wailes, Austral. J . Chem., 1972, 25, 1401; 1971, 24,2533. s 4 J. G. Kenworthy, J. Myatt, and M. C . R. Symons, J . Chem. SOC.( A ) , 1971, 3428. so

"

8


has been investigated and TiCl,,nL (n = 2, L = CH,ClCN or CHC1,CN; n = 1, L = CC1,CN or CH,ClCCl,CN) have been isolated and characterized. These complexes all appear to involve cis-octahedral co-ordination about Ti’V,with those having n = 1 being chloride-bridged dimers. It is suggested that the oxidation involves chlorine abstraction from a co-ordinated cyanide molecule followed by expulsion of e.g. CH,CN, which then polymerize^.^^ The crystal structure of TiC1,,2HCN, which was obtained by addition of TiC1, to HCN, has shown that the molecules have a cis-octahedral structure with average bond lengths Ti-Cl = 222.6(2)and Ti-N = 219.8(7) pm.55 The thiocyanato-complexes (Bu,N)~[TI(NCS),]. (Me,N)2[TiO(NCS),], [Ti(bipy),(NCS),], and [Ti(phen),(NCS),](NCS), have been prepared in acetone solutions, and their i.r. spectra recorded (2500-30 cm- 1).56 Both [Ti(NCS),] and [Ti(NCs),l2- have been identified57 in BuOH solutions containing TiIV and NCS-. Conductometric and spectrophotometric methods were used to investigate the reactions of TiC1, with KSCN and KSeCN in D M F and MeCN solution. Evidence was obtained for species with Ti” :XCNratios of 1:2, 1:4, and 1:6.58 Monomeric addition complexes TiX4,2L (X = C1, Br, or I: L = ethylenethiourea or N-allylthiourea) have been isolated and their i.r. spectra indicate that the potentially ambidentate ligands co-ordinate oia their nitrogen atoms.59 TiCl, reacts with 2 moles of o-HOC,H,CH:NR(L) (R = Me, Et, Pr, Pri, or Bu) to form the complexes TiC1,,2L. The i.r. and electronic spectra indicate that the Schiff base is bound to Ti’’ by the nitrogen lone pair, the phenolic OH group being unaffected by complex formation.60 Similarly, the 2:l addition complexes of 5-(dialky1amino)furals with TiCl, appear to involve co-ordination via the N atom for 5-(dimethylamino)-, 5-(diethylamino)-, and 5-piperidinofural.61 Several new 1 : 1 addition compounds of TiCI, with 2-(arylazo) R2 I

++.aR 8-wR’ \ --r\r

\ /

(4) R = H , p - M e . p-OMe, p-NO,. p-Br, 2,4-Me2,or ?,4,6-Me3 ” 56

” s9

6o 61

RI/ 2

/

\ /

H

( 5 ) R’ = H : R’ = H. p-Me,p-NO,, m-NO,, p-F, or p-OMe R2 = C1: R’ = H or p-OMe

G . Constant, J. C. Daran, and Y. Jeannin, Acra Crysr., 1971, B27, 2388. A. M . Sych and V. P. Dem’yanenko, Zhur. neorg. Khim., 1971, 16, 3000. A. M . Sych, V. V. Garbuz, and A. F. Alekseev, Zhur. neorg. Khim., 1972, 17, 486. J. Masaguer and M . V. Coto, Acra Cient. Cornpostelana, 1970, 7 , 41. P. P. Singh and I. M. Pande, J . Inorg. Nuclear Chem., 1972, 34, 591, 1131. D. Negoiu and A. Kriza, An. Univ. Bucuresri. Chirn., 1970, 19, 113. V. L. Shelepina and V. S. Pustovarov, Ref. Zhur. Khim., Abstr. No. 1Zh26.


9

derivatives of imidazoles (4)62and SH-dibenzo[d,f] [1,3)diazepines (5)63 have been reported. N- und O-Donor Ligunds. The addition of a solution of salen in THF to a solution of TiC1,,3THF in the same solvent, at room temperature under an atmosphere of dry nitrogen, produces a green precipitate which, after some 12 h in the absence of air, affords red crystals. Chemical analysis suggested that the latter is a Ti" compound and this has been confirmed by an X-ray crystallographic study which characterized the compound as [TiCl,(salen)],THF. The [TiCl,(salen)] molecule is on a crystallographic two-fold rotation axis, and has the Ti" in an approximately octahedral environment of two trans chlorine [Ti-Cl = 234.6(2) pm], two cis oxygen [Ti-0 = 183.5(5) pm], and two cis

(6) R (7) R (8) R (9) R (10) R (11) R

p-C(0)Me H p-Me p-C1 = p-OMe = m-OH

= = = =

(12)

(14)

X

(15) X 62

= =

S NH

A. D. Garnovskii, L. I. Kuznetsova, Yu. P. Andreichikov, 0. A. Osinov, Yu. V. Kolodyazhnyi, V. I. Minikin, V. A. Bren, A. M. Simonov, and N. I. Avdyunina, Zhur. obshchei Khim., 1971,41, 1829.

63

L. L. Popova, A. D. Garnovskii, V. I. Minikin, I. D. Sadekov, K. M. Yunusov, and B. V. Lokshin, Zhur. neorg. Khim., 1971, 16, 1308.


10

nitrogen atoms [Ti-N = 214.1(5) The complexes [TiCl,L,] [HL = (6),65 or (7)-(10)66] and [TiCl,L'] [H2L' = salen, (11t(15)66] have been prepared. The complexes are all non-electrolytes and appear to involve octahedral Ti'". with TiC1,L2 having trans chlorine. oxygen, and nitrogen atoms, and TiC1,L' having the arrangement of donor atoms described for [Tiel,( salen)]THF above. Ti(OPr'), reacts with the Schiff bases acetylacetone, 2-hydroxylalkylimines, and N-[(3-hydroxy-2-naphthyl)methylene]-2-hydroxylalky~imines (H,L) in a 1 : l or 1:2 molar ratio to give [TiL(OPr'),] and [TiL,], r e ~ p e c t i v e l y . ~ ~ Similarly, Ti(OR), (R = Et or Bu') react with N-salicylidene-2-hydroxyethylamine (H,L') to form [TiL'(OR),] or [TiL:]. Treatment of [TiL'(OEt),] with MeOH gives [TiL'(OMe),] and both these alkoxides appear to have the dimeric structure (16), whereas [TiL'(OBu')] and TiLi are monomeric.68

(16)

R

=

Me or Et

Triazene 1-oxides (17) in methanol react with TiC1, to give dinuclear complexes which are suggested to have the oxygen-bridged structure (18) on the basis of i.r. and 'H n.m.r. studies.69

c1

(17) R

Me or C1

(18)

R 6A

65

66

6' 68

69

G. Gilli, D. W. J. Cruickshank, R. L. Beddoes, and 0. S. Mills, Acta Cryst., 1972, B28, 1889. N. S. Biradar, V. H. Kulkami, and V. B. Mahale, Indian J . Chem., 1971, 9, 1410. N. S. Biradar and V. H. Kulkarni, J . Inorg. Nuclear Chem., 1971, 33, 3847. P. Prashar and J . P. Tandon, Z . anorg. Chem., 1971, 383, 81. D. Negoiu and A. Kriza, An. Univ. Bucuresti. Chim., 1970, 19, 31. P. S. Zacharias and A. Chakravorty, Inorg. Nuclear Chem. Letters, 1972, 8, 65.


11

P-Donor Ligands. 'H and 3 1 Pn.m.r. studies of tertiary phosphine adducts of TiC1, in dichloromethane solution suggest the existence of fast, temperaturedependent equilibria involving the 1: 1 (trigonal-bipyramidal) and 1:2 (cisoctahedral) TiCl,-PR3 adducts and free PR3 (R = Me, Et, Pr', Bu, Ph, or cyclohexyl). Several of these 1: 1 and 1:2 adducts have been isolated for the first time and characterized by analysis and i.r. spectroscopy. At low temperatures (cu. 210K) there is some evidence for the formation of dimeric species, formulated as [C13TiCI,TiCl,PR3].70 0-Donor Ligands. A large number of studies have been concerned with the preparation and properties of titanates and Ti'' mixed oxide compounds. Li,TiO, has been prepared71 by heating a 2: 1 mixture of LiC03 and TiO, at 800-900 "C for several hours. The compound is isostructural with Li,GeO, and thus involves tetrahedrally co-ordinated Ti". The i.r. spectrum of Li,TiO, is consistent with this structure. Other vibrational spectral studies of [TiO,]"units have also been reported.72Heats of formation of some titanates have been estimated73and the crystal chemistry of titanotantaloniobate~~~ and titanian Table 1 Some studies on titanates and Ti" mixed oxides Compound a-Na,TiO, p-Na,TiO, Na,Ti,O, Na4Ti,08 Na,Ti,O,, Na8Ti5O

,

Na,TiO Na8Ti,OI4 CaTi40g BaTi,O,,

Source

Na,O-TiO,

J Na, CO ,-TiO,

BaO-TiO, (1 :4) at 1460 "C BaO-TiO,-Al,O,

Al,Ti05

Ga,TiO, Ga,Ti,O, In,TiO,

U

m.p. 1300 "C (decomp.) m.p. 1030 "C, X

Ba4Ti 13O3 0

BaTi,Al,O,,

Properties reported Re$ metastable m.p. 965 "C, X

Ga,O,-TiO, In,O,-TiO,

X

b

t.d., X st, TiO, octahedra st, TiO, distorted octahedra m.p. 1470"C, t.d., X pseudobrookite structure with disorder on metal sites m.p. 1590 "C, X m.p. 1680 "C, X m.p. 1750 "C, X

C

d

f g

h i

F. Calderazzo, S. A. Losi, and B. P. Susz, Helv. Chim. Acta, 1971, 54, 1156. " B. L. Dubey and A. R. West, Nature, 1972, 235, 155. 7 2 (a) F. Gonzalez-Vilchez and W. P.Griffith,J. C . S. Dalton, 1972, 1416; (b) I. I. Plyusnina and L. A. Zaitseva, Izvest. Akad. Nauk S.S.S.R.,Ser. geol., 1971, 104. 7 3 K. Schwitzgebel, P. S. Lowell, T. B. Parson, and K. J. Sladek,J. Chew. and Eng. Data., 1971. 16.41 8. 74 G. A. Sidorenko, Roentgenogr. Miner. Syr'-va, 1970, No. 7, 21. 70

12


Table 1-continued Source

Compound

1

Tl,TiO, Tl,Ti20, CL-, p-, and y-T1,Ti307 T1,Ti,09 T12Ti,MgOlb CaTiSiO M ,TiA, 0 (M = K, Rb, or T1; A r-Si or Ge) NaK,Ca,TiSi,O ,(OH)

,

X

under N, stream CaSi0,-TiO, M,C03-Ti0,-A02 at 550 "C and then at 8-1 200 "C

X

k

X

1

st, TiO, m distorted octahedra

BaCO,

+

+ TiO,

X

n

x

0

(NH4)2HP04

300 "C/24 h and 1100 "C/several days

,

+

Ti,ZrOl,

Ca,Ti,Nb,O Ca,'fi,Nb,,O,, Bi,TiNbO,

Ref.

TiO,-Tl,CO, 500-1000"C

MTiOPO, (M = K, Rb, or T1) BaTiP, 0,

Bi,Ti,O

Properties reported

I

,

T i P 2 0 7 ZrP,O, (1 : 1) 1580 "C/7 days; cpd. in melt CaNb,O,-TiO,

st, TiO, slightly p distorted octahedra X, rutile structure 4

X

k

st

r

ceramic techniques

X

S

TiO, + MOO, at 650 "C Bi,Ti,O,,-Bi,MoO, below 325 "C

m.p. 1050°C (decomp), X

t

X

U

st, p

U

Ni 0-TiO,

m.p. 1775 "C, i.r. ilmenite structure

W

1 0Ti2Nb8030

( M l o = 4K + 4Li + 2Sr or 4Li + 4Sr, Ba, or Pb) 10Ti4Nb6030

( M l o = 2Li + 4K M ,Ti ,Nb 0, (M, = Bi or La)

,

M6Ti,0030

(M6 = 4La"' Ti,MoO,

+ 2La)

+ 2CeIV)

Bi,,Ti,Mo,O,, Co,TiO, NiTiO, Cu ,Ti2O,

MTiO, MTi,O, (M = Hf, Zr, Ce. or Th)

Cu,O-TiO, (1-10: 1) at 900-1 100 T

x

st, chains of TiO, octahedra; reduction by H, or CO

Y


13

Table 1-continued Compound

Source

Na,TiWO,F,

NaF + TiO, at 700 "C

MTi WO ,F (M' = Rb, Cs, or T1) NaMTi WO,F (MI' = Ca, Sn,or Pb) M ,Ti WO (M" = Sn, Pb, or Cd) Na,TiNbO,F, NaSnTiNbO,F, Sn,TiNbO,F TITiNbO,F,

+ WO,

Properties reported

Ref

X , orthorhombic

z

MF or MF, + T i 0 2 X, pyrochlore lattice z +WO, or Nb,O, at high temperatures

( a ) R. Bouaziz and M. Mayer, Compt. rend., 1971, 272, C , 1773, 1874: S. Launay, M. Mayer, and R. Bouaziz, ibid., 1971, 273, C, 54. (b) S. V. Ponomareva, Kh. N. Nurmagambetov, S. A. Shcherban, and Yu. F. Klyuchnikov, Zhur. priklad. Khim., 1971, 44, 1529. (c) T. F. Limar, N. G. Kisel, I. F. Cherednichenko, and A. I. Savos'kina, Zhur. neorg. Khim., 1972, 17, 559. (d) E. Tillmanns, Cryst. Struct. Comm., 1972, 1, 1. (e) E. Tillmanns, Inorg. Nuclear Chem. Letters, 1971,7, 1169. ( f ) J. P. Guha and D. Kolar, J. Amer. Ceram. Soc., 1972, 55, 55. (9)B. Morosin and R. W. Lynch, Acta Cryst., 1972, B28, 1040. (h) F. M. Spiridonov, I. A. Rozdin, M. N. Sotnikova, L. M. Komissorova, and V. E. Plyushchev, Zzoest. AkaJ. Nauk S.S.S.R., Neorg. Materialy, 1971, 7, 817, 1801. ( i ) I. A. Rozdin, F. M. Spiridonov, L. N. Komissorova, and V. E. Plyushchev, ibid., 1971, 7, 1798. Q A. Verbaere and M. Tournoux, Bull. SOC.chim. Frunce, 1972, 896. ( k ) A. Jongegan and A. L. Wilkins, J. Less-Common Metals, 1971,25, 345. (0 J. Choisnet, A. Deschanvres, and B. Raveau, Compt. rend., 1971,273, C, 1 5 0 4 . (m) A. A. Petrunina, V. V. Ilyukin, and N. V. Belov, Doklady Akud. Nauk S.S.S.R., 1971, 198, 575. (n) R. Masse and J. C. Grenier, Bull. SOC.frunq MinCral. Cristallog., 1971, 94, 437. (0)R. Masse add A. Durif, Compt. rend., 1972,274, C, 1692. (p) J. F. Dorrian, R. E. Newnham, D. K.Smith, and M. I. Kay, Ferroelectrics, 1971,3, 17. (4)W. Gebert and 0. W. Florke, Nuturwiss., 1972,59, 78. ( 7 ) R. W. Wolfe, R. E. Newnham, D. K. Smith, and M. I. Kay, Ferroelectrics, 1971, 3, 1. (s) Chan-Van-Thieu, N. N. Krainik, E. E. Myl'nikova, I. G. Ismailzade, V. I. Isupov, F. A. Agaev, and I. S. Chmel, Izoest. Akad. Nauk S.S.S.R., Ser.Jiz,, 1971,35, 1825; T. Ikeda, T. Haraguchi, Y. Onodera, and T Saito, Jap. J 4 p p l . Phys., 1971,10, 987. (t) R. Krishnamurthy and V. S. Chincholkar, Current Sci., 1972,41, 36. (u) N. P. Smolyaninov, 0. B. Bochkareva, S.Marenich, and A. I. Arbuzova, Zhur. neorg. Khim.,1971,16,2299. (o) R. J. Bequm, M. L. Rao, and N. S. S. Murthy, Proceedings of the 15th Ngclear Physics and Solid State Physics Symposium, 1970, 3, 693. ( w ) M. Zaharescu and C. Gh. Macarovici, Rev. Roumuine Chim., 1971, 16, 1323. (x) A. 1. Sheinkman, V. G. Mukhin, L. M. Gol'dshtein, and G. V. Kleshchev, U.S.S.R.P., 319 551 (CI.C.Olg), 1971. (y) A. Kahn-Harari, Znternat. Hautes Temp. Refract., 1971, 8, 71. (z) J. P. Miranday, G, Gauthier, and R. De Pape, Compt. rend., 1971, 273, C,970.

garnet75 have been reviewed. Table 1 summarizes other work reported concerning titanates and Ti" mixed oxide compounds. Oxidation of the pseudooctahedral MeTiCI,,XCH,CH,Y (X or Y = OMe, SMe, or NMe,) with dry oxygen in dichloromethane solution at room temperature has been shown to give the corresponding methoxy-derivatives, MeOTiCI3,XCH,CH,Y. Variable-temperature n.m.r. studies on these latter complexes have indicated that most of them undergo intramolecular exchange between mer and f u c forms at room temperature. All these TitV-OMe complexes exhibit strong i.r. absorptions at 1100 [v(C-0)] and 600 [v(Ti---0)] cm-1.76 An examination 75

E. Dowty, Amer. Mineral., 1971, 56, 1983.

76

R.J . H. Clark and A. J. McAlees, J. C. S. Dalton, 1972, 640.

14


of the reduction of molecular nitrogen by a Ti(OPr’),-Na napthalenesystem has been made, and the reaction conditions optimized to yield 1.32 molecules of NH, per titanium. A compound of empirical formula Na,,Ti,N,(OPr’),o, believed to be the reduced nitrogen-containing species, has been isolated after reduction ; however, no dinitrogen species could be isolated prior to reduction.77 Dilithium perfluoropinacolate, Li,[ (CF,),CO],, obtained from metallic lithium and hexafluoroacetone, reacts with TiCl, to form the covalent derivative (19).’* +

CF,

CF,

CF,-

I I C -C -CF, I @I @ \

c1’

Ti

/

\c1

The full account of the crystal structure of [Ti(OPh),PhOH], has been p~blished.’~ The reaction of Ti(OBu), with P(CH,OH),, HOP(O)(CH,OH),, or (HO),P(O)CH,OH, under an atmosphere of nitrogen at 90-95 “C, gives (20), (21), or (22), respectively. When a 1:4 ratio of these reagents is used,

H 0(01P 0 ’‘

Ti

P(O)OH

’o\

Ti[OCH2P(CH20H)],, Ti[OCH,P(O)(OH)CH,OH],, or Ti[OCH,P(O)(OH),], is obtained.80 At - 40 “C or below, TiCI, forms unstable addition complexes with RtP(OR2) ( R ’ = Et or Ph, R2 = alkyl), which lose R2C1 slowly in the cold. or rapidly at l50-16OoC, to form the corresponding 77

79

R. H. Greeley, Diss. Abs. ( B ) , 1971, 31, 6503. A. P. Conroy, Diss. Abs. ( B ) , 1971, 31, 3901. G. W. Svetich a n d A. A. Voge, Actu Cryst., 1972, Bt8, 1760. E. V. Kuznetsov and E. K. Ignat’eva. Trudy Kazun Khini.-Tekknol. Inst.. 1969. 40, 196.


15

R,POTiCl, derivative.8' An i.r. and Raman spectral study of 1: 1 and 1: 2 complexes of TiCl, with (RO),PO (R = Et or Bu) in CS, or cyclopentane solution has been reported.82 The dissociation of crystalline TiC14,2POC13 has been ~ t u d i e d , ' ~ and the values of -71.5 & 3 and -87.0 i-6 kJ mol-' obtained for the heats of formation of TiCl,,POCl, and TiC1,,2POC13, respectively, are in excellent agreement with those values reported last year. The bis(organophosphiny1oxy) derivative (24) has been obtained by heating a mixture of Ti(OBu), and (23). (BuO),Ti[O(0)PR'R2] (R1 = Me, PhO, or

(23)

(2 4)

Ph, R2 = BuO, PhO, or Ph; R1R2 = o-C6H,02) have been synthesized in a similar manner. The compounds are generally stable towards pyrolysis, although the methylene-o-carboranene group is easily lost from (24) during pyrolytic ~ x i d a t i o n . ~1.r. , spectra of Ti" complexes with Arsenazo I or Thoron I have revealed that the metal is bound to an (AsO,(OH) group, and that the ligands retain their quinone hydrazone structure.85 The phase diagram for the Ti02-RbS04-H20 system has been determined, and the double sulphates Rb2S0,,TiOS0,, Rb,SO,,Ti(SO,),, and 2Rb,S04,TiOSO,,Ti(SO,), have been prepared by heating a mixture of Rb2S04 and TiO, in concentrated sulphuric acid at 250-300 "C. The formation constants of M2S0,,TiOS0, (M = Rb or Cs) in sulphuric acid (1-10 mol 1-') have been determined as 0.39 & 0.23 and 0.33 & 0.17, respectively.86 The 1:1 complexes formed by pyrogallol-4-carboxylic and gallic acids with Ti" in sulphuric acid have been characterized spectrophotometrically.87 The reactions of terepht halic acid with the various titanium tetrabutoxides have been studied, and the nature of the products was found to depend upon the nature of the alkyl group, Ti(OR), (R = Bu or CHMeEt) react with p-C, H,(CO, H), to form [(RO),TiO,CC, H,CO,Ti(OR),] 2O; Ti(OBu'), gives [-T~(OBU'),O,CC,H~CO~-]~.Ti(OCH,CHMe,), and p-C,H,(CO,H),, 1: 1 and 1: 2, afford (Me,CHCH,O),TiO,C,H,CO,H and p-[(Me,CHCH,O),Ti0,C-],C,H4, respectively.88 Electrolysis of TiCI, in ethyl caproate, heptyl

82

'' 84

85 86

A. N. Pudovik, A. A. Muratova, M . D. Medvedeva, Zhur. obshchei Khim., 1972,42,469. G. Roland, B. Gilbert, and G. Duyckaerts, Spectrochim. Acta, 1972, 28A, 835. E. K. Krzhizhanovskaya and A. V. Suvorov, Zhur. neorg. Khim., 1971, 16, 2542. 3380. K. A. Andrianov, N. V. Varlamova, A. G. Kolchina, V..V. Severniyi, and A. S. Shapatin, Zhur. obshchei Khim., 1970, 40, 1560. A. T. Pilipenko and L. L. Shevchenko, Zhur. neorg. Khim., 1971, 16,2124. Ya. G. Goroshchenko and S. A. Filatova, Zhur. neorg. Khim., 1971, 16, 1569; 2996. S. Ya. Shnaiderman and A. M. Pleskonos, Izvest. V . U.Z . Khim. ikhim. Tekhnol., 1972,15, 178. N. Yoshino and T. Yoshino, Kogyo KagakuZasshi, 1971,74,1673.

16


acetate, octyl formate, and ethyl monochloroacetate esters (R'C02R2) has been used to evaluate ionic equilibria in such solutions. With increasing size of the alcohol radical and electronegativity of the acid radical, the equilibria are displaced towards the [TiCl,,R1 C O 2R2 and TiCl ,,R'C02R2] species." Dimethoxyethane forms a 1: 1 adduct with TiC1, which has been assigned a cis-octahedral monomeric structure from i.r. studiesg0 The crystal structure of [TiCl,(acac)] has shown the compound to consist of centrosymmetric chloride-bridged dimers in the solid state. Each Ti" is approximately octahedrally co-ordinated by a bidentate acac and four chloride ligands. The solution behaviour of [TiX,(fLdiketonate)] (X = C1 or Br) requires further clarification. N.m.r. studies suggest that for [TiCl,(PhCOCH,COMe)] the solution equilibrium +

2TiCl,(bzac) e TiCl,(bzac),

+ TiCl,

exists, although i.r. and molecular weight data are consistent with the undissociated five-co-ordinate monomer., Thermal and kinetic studies have been reported for [TiCl,(a~ac),].'~ TiCI,,L' and TiC1,,2L2 (L', L2 = acetyleneurea, N-allylurea, N-allylacrylamide, or N-allylbenzylamide; L2 = ethyleneurea) have all been shown by i.r. spectroscopy to involve 0-bonded amido-ligand~.~'Naphthaldehyde and furaldehyde(L) react with TiX, to give the adducts TiX4,2L (X = C1 or Br), whereas phthalaldehyde forms TiX,,L. These coloured addition compounds are non-electrolytes and appear to involve an octahedral TiCl,O, c h r o m ~ p h o r e . ~ ~ The 1 :2 adduct of TiCl, with phenyl-5-(methylamino)fural appears to be 0-bonded, the steric and inductive effects of the phenyl group apparently inhibiting N-bonding.,l 1,2-Anthraquinone forms a 1: 1 addition compound with TiCl,, and 2TiCl,,quinone compounds are obtained with 1,4-anthraquinone 5,12naphthacenequinone, and 6,13-pentacenequinone. The decrease in v(C-0) of these quinones on co-ordination varies between 160 and 100 cm- the magnitude of the shift decreasing with increasing oxidation-reduction potential of the quinone. The polymeric [TiCl,,l ,4-benzoquinone], adduct has been prepared in dichloromethane solution at - 60 "C with complete exclusion of moisture. In benzene TiCl,,1,4-benzoquinone,C6H6was obtained.93

',

S-Donor Ligands. The full account of the crystal and molecular structure of tetrakis-(NN-diethyldithiocarbamato)titanium(iv),[Ti(S2CNEt2),], has been = 260.6(8) and Ti-S, = 252.2(8) pm published. The difference in the Ti-S, bond lengths in the trigonal-dodecahedra1 structure could be due to n-donation a9

90 91

92

93

Yu. A. Lysenko. L. I. Khokhlova. and L. F. Isachkina, Zzvesf. V.U.Z. Khim. i khim. Tekhnol., 1971, 14, 1777. E. Hengge and H. Zimmermann, Monatsch., 1972, 103,418. G. Beech and R. M. Lintonbon, Thermochim. Acta, 1971, 3,97. R.C. Paul, H. R. Singal, and S. K. Chadha, Indian J . Chem., 1971,9,995. R. Giallonardo and B. P. Susz, Helv. Chim. Acta, 1971,54, 1400; R. Giallonardo, ibid., p. 2496.


17

from the S, pn-orbitals into the metal d,z-yz orbital.94 Stable 1:l and 2: 1 complexes of perhydrothioxanthen with TiCI, have been prepared and characterized.' Halogen-donor Ligands. The equilibrium constants for M,TiF,(s)

+ H,O(g) + M,TiOF,(s) + HF(g)

(M = K, Rb, or Cs) have been determined, and the free-energy changes at 350°C are 49.5, 54.5, and 52.0 kJ mol- ',re~pectively.'~A differential-thermal study of NH,TiF, has been reported.97MTiF, (M = Mn, Co, or Ni) have been prepared by the thermal dehydration of the hexahydrates in HF, and MTiF, (M = Zn or Cd) by the pressure fluorination of (NH,),ZnCl, and CdCO,, respectively, in the presence of TiO,. All the compounds are isostructural with VCl,, with the exception of CdTiF, which is of the LiSbF, structure type.98 A new synthesis for ilmenite has been reported.99This involves the controlled thermal decomposition (350-1000°C) of [Fe(H,O),] [TiF,] in a 95: 5 nitrogen: hydrogen atmosphere saturated with water vapour at 50-75 "C. F' n.m.r. spectroscopy has been used to examine the stoicheiometry and structure of TiF,Br4-.,2THF and TiF,Br4-,,1,2-dirnethoxyethane (x = 1 4 ) complexes. All the complexes are apparently octahedral and in some cases geometrical isomers have been characterized.'" M2TiC1, (M = K, Rb, Cs, or NH,) have been prepared by the addition of anhydrous MCl to a solution of TiCl, in acetyl chloride solution, and their i.r. spectra determined.", Normalco-ordinate analyses of [TiCl6I2- and [TiBr,12- have also been reported.lo2 Titanium metal is oxidized by bromine in D M F solution and [TiBr(Br,),DMF] has been characterized as a product of the reaction.'03 Organometallic Titanium(rv) Compounds.-Charge-transfer interactions between TiCl, and aromatic hydrocarbons and fluorocarbons have been characterized by spectrophotometric studies.' O 4 The other work described here will mainly be concerned with selected aspects of the chemistry of Ti''alkyl and -cyclopentadienyl derivatives. AEkyl and Related Compounds. The i.r. spectra of MeTiC1, and Me,TiCl, and their deuteriated analogues have been redetermined; the results do not agree with those obtained in earlier studies, and it would appear that authenticated samples of deuteriated compounds must be obtained before these discrepancies 94

95 96 9'

98 99 loo lo'

lo* lo3

lo4

C

M. Colapietro, A. Vaciago, D. C. Bradley, M. B. Hursthouse, and I. F. Rendall, J . C. S. Dalton, 1972, 1052. E. N. Kharlomova, E. N. Gur'yanova, and V. G . Kharchenko, Zhur. stnckt. Khim., 1971,12,637. Yu. N. Sklyadnev and M. A. Mikhailov, J . Less-Common Metals, 1971,25,336. M. A. Mikhailov and D. G. Epov, Zhur. neorg. Khim., 1972,17, 113. R. H. Odenthal and R. Hoppe, Z . anorg. Chem., 1971, 383, 104. P. J. Gellings, K. A. DeJonge, andG. M. H. Van deVelde, Chem. andInd., 1971,1433. R . S. Borden, Govt. Rep. Annourrce, ( U . S . ) , 1971,71, 54. R. Uson and V. Riera, Rcc. Acad. Cienc. exactasfis-quim. natur. Zaragoza, 1971, 26, 625. M. N. Avasthi and M. L. Mehta, Z . Naturforsch., 1971, %a, 1134, 1137. W. R. Windolph and A. J. LeflYer, Inorg. Chem., 1972, 11, 594. L. A. Burkhardt, P. R. Hammond, R. H. Krupe, and R. R. Lake, J . C. S. Dalton, 1972, 3789.

18


can be resolved. The exchange of Me groups between MeTiC1, and Me2TiCl2 and each of these compounds with Me,Zn was also studied, using 'H n.m.r. s p e c t r o s ~ o p y . 'The ~ ~ i.r. spectra of complexes of MeTiC1, with THF, MeCN, py, and PPh, have been reported.'06 The pseudo-octahedral [MeTiCl,L] complexes (where L is an unsymmetrical bidentate ligand : methyl p-dimethylaminoethyl ether. methyl (3-methylthioethyl ether. or P-dimethylaminoethyl sulphide) have been prepared by mixing hexane solutions of MeTiC1, and the appropriate ligand. The complexes are intensely coloured solids which are extremely sensitive to oxygen and water, and are thermally unstable even at room temperature. N.m.r. studies have shown that these complexes prefer to adopt the mer configuration with the harder ligand atom (0 > N > S ) trans to the Me group: however, exchange between the two mer-isomers has been indicated by variable-temperature n.m.r. studies. The corresponding TiC14 complexes were prepared and studied for comparison. In contrast to the above, the react ion of M eTiC1, with N NN'N'-te t ra met hyl-o-amino benzylamine (L' ) affords the light-green Ti"' complex [TiC13L1].lo7 New dinuclear anionic derivatives of MeTiC1, have been prepared by treatment with Et,NCl or Et,NBr. With the reactants in the mole ratio 2:1, [Me,TiCl,] - or [Me,TiCl,Br]-, respectively, are obtained and spectroscopic studies suggest that these dark-violet anions consist of two octahedra sharing a face of bridging chloride ligands. A 1:1 stoicheiometry of the reactants affords the brown [Me2TiC1,I2- or [Me2TiCl,Br2]2- ions, respectively, which appear to involve two octahedral units linked by an edge of bridging chloride ligands. The blue-black mononuclear octahedral complexes [MeTiC1J2 - or CMeTiC1,Br2I2- are obtained with an excess of Et4NCl or Et,NBr, respectively."' This year, considerable interest has been shown in the preparation and properties of compounds which involve four Ti-C 0-bonds, particularly where olefin formation by hydride transfer from the P-carbon of the organic group is not possible. Such interest is of course a manifestation of the new developments in the chemistry of transition-metal-carbon o-bonded compounds. Tetra-(1-norbornyl) titanium, Ti(C,H, ,)4, has been prepared from the and the corresponding reaction of TiC14,2THF and 1 -n~rbornyl-lithium,~ neopentyl compound, Ti(CH2CMe3)4,has been obtained in a similar manner.4 l ~ ] LiCH,SiMe,) The full account of the preparation {from [ ( ~ r - C p ) ~ T i Cand has been r e p ~ r t e d . "The ~ thermal and properties of [(~c-cp),Ti(CH,SiMe,)~~ stability and decomposition mechanisms for TiR, compounds (R = Me, Bu, Ph, Bz, vinyl, or cyclohexyl) have been determined.' l o The decomposition of TiMe, and its deuteriated analogue in pyridine, heptane, and diethyl ether at 10--30°C have been investigated. Two reaction paths were identified: the '05

Io6

J. F. Hanlan and J. D. McCowan, Canad. J . Chem., 1972,50, 747. 0.S. Roshchupkina, N. E. Krusch, F. S. D'yachkovskii, and Yu.G. Borod'ko, Zhur.fiz. Khim., 1971,45, 1329.

lo*

Io9 'lo

R. J. H. Clark and A. J , McAlees, Inorg. Chem., 1972, 11, 342. R. J. H. Clark and M. Coles, Chern. Comm., 1971, 1587. B. Womiak, J. D. Ruddick, and G. Wilkinson, J . Chem. SOC.( A ) , 1971,3116. R. Tabacchi and A. Jacot-Guillarmod. Chiniia (Sw ir z . ), 1971, 25, 326.


19

major one involves disproportionation to CH, and Me Ti=CH [which reacts further to give TiMe,, CH,(TiMe,),, and H,&i(Me),], and the other less important route involves homolysis of Ti-C bonds.' The organogermaniun titanium dialkylamides, Ph,GeTi(NR,), and (Ph,Ge),Ti(NR,), (R = Me or Et) have been obtained by treating the appropriate dialkylamido-titanium bromide with LiGePh,. The compounds were characterized by 'H n.m.r. and i.r. spectroscopy.' The determination of the crystal structure of tetrabenzyltitanium at - 40 "C has resolved the confusion concerning the n.m.r. spectra reported for this compound. The average Ti-C bond length is 213(4) pm; however, the main feature of interest is the average value of the Ti-C-C interbond angle of 103", which contrasts with the value of 111" for the corresponding angle in tetrabenzyltin6 The interpretation of this difference in terms of an interaction of the aromatic ring with the empty &orbitals of the titanium is consistent with the observation that the n.m.r. spectrum of TiBz, depends upon the method of preparation. If this involves pyridine the spectrum is that expected for a o-bonded complex; however, in the absence of any such donor the spectrum signifies n-co-ordination of the ligands.'', The i.r. spectrum, however, does not give any indication of this n-co-ordination.' [(n-Cp),Ti(Bz),] (in heptane solution) reacts with carbon monoxide at 25-30 "C and 1 atm to form [(n-Cp),Ti(Bz)(COBz)], which subsequently affords [(n-Cp),Ti(CO),]. This provideslt4 a simpler synthesis of the dicarboxyl compound than that previously reported. X-Ray studies have shown that di-n-cyclopentadietyldiphenyltitanium involves two n-Cp rings and two o-bonded phenyl groups, Ti-C = 227(1) pm.'I5 The compound exhibits a novel carboxylation reaction with C 0 2 at 80-90°C to afford the derivative

''

(25) and benzene.116 An X-ray diffraction study has shown that the sixmembered ring is planar, with Ti-0 = 195 and Ti-C = 220 pm."' SOz reacts with dicyclopentadienyltitanium alkyl and aryl derivatives to form the

'" ''

IL4

'I7

F. S. D'yachkovskii and N. E. Krusch, Zhur. obshchei Khim., 1971,41, 1779. H. Biiper and H. J. Neese, J . Organnnietallic Chem., 1971, 32,223. R Tab'icchi and A Jacor-Guillarmod, Hclv.Ch/m Acta, 1970. 53, 1977. (a) W. Bruser, K. H. Thiele, P. Zdunneck, and F. Brune, J . Organometallic Chem.. 1971. 32, 335; (b) G. Fachinetti and C. Floriani, J . C. S. Chem. Comm., 1972, 654. V. Kocman, J. C . Rucklidge, R. J. O'Brien, and W. Sante, J . C. S. Chem. Comm., 1972, 1340. M . E. Vol'pin, I. S. Kolomnikov, T. S. Lobeeva, V. V. Gorbachevskaya, G. G. Aleksandrov, and Yu. T. Struchkov, Chem. Comm., 1971, 972. G . G. Aleksandrov and Yu. T. Struchkov, Zhur. strukt. Khim., 1971, 12,667.


20

corresponding red monomeric 0-sulphinato-complexes by insertion into the Ti-C o-bonds. [(~-Cp),Ti(0,SMe)l,[(x-Cp),Ti(O,SMe)Cl], and [(n-Cp),Ti(O,SPh),] were prepared in this manner.' l 8 Cyclopmtcrdienyl Derivcrtices. The crystal structure of tetra(cyclopentadieny1)titanium has been determined:7 the molecules contain two h5- and two h'cyclopentadienyl groups. The metal atom thus has a 16-electron configuration. Variable-temperature n.m.r. studies have identified facile interchange of the o- and n-bonded cyclopentadienyl groups, the activation energy of the exchange process being 67.5 1.3 kJ mol-'. The crystal structures of [(rt-Cp)2TiC12]"9 and [(CH,)3(n-Cp),]TiC1,120 have been determined and average Ti-Cl bond lengths of 236 and 237 pm, respectively, identified. [(n-Cp),TiCI,] reacts with primary and secondary amines R,NH (NH,, Me,NH, EtNH,, or piperidine) to form the corresponding [(n-Cp),Ti(R,N)Cl) derivative. Tertiary amines, py, PhNH,, and Ph,NH, do not react and it is suggested that, for reaction, the amine must be sufficiently basic to make an initial attack on the [(n-Cp),TiCI,] molecule, and also that it should contain an N-H group to complete the ammonolytic process. ,' Lithium acetylpentacarboxylchromate. [(CO),CrC(Me)OLi], reacts with [(n-Cp),TiCl,] at cci. room temperature to form [(CO),CrC(Me)OTi(n-Cp),Cl] and [ ((CO),CrC(Me)O},Ti(rc-Cp),]. 'H N.m.r. and i.r. studies have indicated that the electronegativity of the (CO),CrC(Me)O group towards (n-Cp),Ti is approximately equal to that of chloride.'22 A mixture of rn- and p-nitrobenzoyl peroxide reacts with titanocene in THF solution to form the corresponding [(n-Cp),Ti(0,CC,H4N0,)2] benzoate derivative^.'^^ The i.r. spectra of these compounds suggest that they involve unidentate carboxylato-groups.' 2 4 [(x-Cp),Ti(NCO),] and [(x-Cp),Ti(NCS),] have been shown to involve N-bonded cyanato- and thiocyanato-ligands by i.r. and mass spectrometric studies.12, [(n-Cp),TiX,] (X = C1 or Br) react with M2P4Ph, (M = Na or Li) in dioxan to give diamagnetic, dark-violet, bis-(n-cyclopentadieny1)-(1,2,3-triphenylphosphanato-P',P3)-titanium(26). The presence of the four-membered ring was proved by 3 1 Pn.m.r. and mass spectral studies.'26 The insoluble complexes (27) have been prepared by the room-temperature reaction of the appropriate cyclo-octa-1.5-diene cuprous halide dimer with [(n-Cp)2Ti(SR),].in toluene. under an atmosphere of nitrogen. The existence ofa Ti-Cu bond & suggested from comparative spectral studies with [(n-Cp),-

'

'la

"O

12 1

"' 12' 126

P. C. Wailes, H. Weigold, and A. P. Bell, J . Organometallic, Chem.. 1971, 33, 181. V . V . Tkachev and L. 0. Atovmyan, Zhur. strukt. Khim., 1972, 13,287. B. R. Davies and I. Bernal, J . Organometaflic Chem., 1971. 30.75. L. J. Baye, Synth. Inorg. MetaLorg. Chem., 1972, 2, 47. E. 0. Fischer and S. Fontana, J . Organometallic Chem., 1972,40, 159. G . A. Razuvaev, V. N. Latyaeva, and A. N. Lineva, Zhur. obshchei Khim., 1971,41, 1556. N. N. Vyshinskii, T. 1. Ermolaeva, V. N. Latyaeva, A. N. Lineva, and N. E. Lukhton, Doklady Akad. Nuuk S . S . R . , 1971, 198, 1081. E. A. Deardorff. Diss Abs. (B). 1971. 31. 5236. K. Issleib, G. Wille, and F. Krech, Angew. Chem. Internat. Edn., 1972, 11, 526.


21

Ti(SR),M(CO),] (M = Cr, Mo, or W) where the presence of a Ti-M bond has been established.' The compounds [(x-Cp)TiClL,] (HL = acac, 1 -phenylbutane-1,3-dione, or 1,3-diphenylpropane-1,3-dione) have been prepared by the reaction of

(26)

(27) R = Me or Ph X = C1 or Br

[(x-Cp),TiCl,] with HL and Et,N (1 :2: 1) in MeCN at 20 "C.Variable-temperature n.m.r. studies of solutions of these monomeric covalent compounds have indicated the presence of cis- and trans-isomers for [(IT-Cp)TiCl(acac)],but only cis-isomers for the other two complexes.' 2 8 An efficient room-temperature preparation of (n-Cp),Mg has been achieved by the addition of a catalytic quantity of(z-Cp)TiCl, to a reaction mixture ofcyclopentadiene and magnesium metal in THF.'29

2 Zirconium and Hafnium Introduction. -The fifth ionization potential of zirconium has been re-evaluated as ca. 80.36 eV from spectroscopic studies.13'. 13' A text describing the analytical chemistry of zirconium and hafnium has been ~ u b l i s h e d , and ' ~ ~ the methods of separation of these two elements have been r e ~ i e w e d . ' ~There , has been a marked increase in the number of papers concerned with zirconium and hafnium chemistry published this year, although the majority of studies have been concerned with compounds involving MIv-oxygen bonds. Interesting developments in the chemistry of zirconium and hafnium include the preparation and characterization of salts involving the pentakisborohydrido-anions of these metals, [M(BH,),]-.134 Tetraneopentylzir~onium~ and tetra-(1norborny1)-zirconium and -hafnium5 have been isolated in studies which have extended the range of alkyl derivatives of the early transition metals. The crystal structure of tetrabenzylhafnium has been determined at - 40 "C:the molecules P. S . Braterman and V. A. Wilson, J . Organometallic Chem., 1971, 31, 131. M. J. Frazer and W. E. Newton, Inorg. Chem., 1971, 10. 2137. T. Saito, Chem. Comm., 1971, 1422. 130 N. S. Z. Chaghtai and Z . Ali, Zndian J. Phys., 1971,44,330. 1 3 1 J. Reader, G. L. Epstein, and J. 0. Ekberg, J . Opf.SOC.Amer., 1972,62,273. 13' S . V. Elinson and K. I. Petrov, 'Analytical Chemistry of Zirconium and Hafnium', Ann ArborHumphrey: Ann Arbor, Mich, 1969. 133 Y . Mori, Shin Kinzoku, 1970,52,28 (Nuclear Sci.Abs., 1971, 25,26150). 1 3 4 M. Ehemann and H. Noth, 2. anorg. Chern., 1971, 386, 87.

22


were shown to be essentially isostructural with their zirconium analogues, and thus apparently to involve some interaction between the aromatic ring and the transition metal, in addition to the four metal-carbon o-bonds.6 X-Ray crystallographic studies have established that tetracyclopentadienylhafnium involves two h5- and two h'-cyclopentadienyl rings.' 3 5 The molecule thus resembles the titanium analogue, but differs from [(n-Cp),Zr(Cp)]. Facile exchange of the non-equivalent cyclopentadienyl rings in both the hafnium and zirconium compounds has been identified in low-temperature n.m.r. studies." The complexes [(n-Cp),M'CIM2Ph,] (M' = Zr or Hf. M2 = Si or Ge) have been prepared.136Since they are do complexes the metal-metal bond must be a pure o-bond, and the large Zr-Si separation of 281.3(2) pm in [(n Cp),ZrClSiPh,] emphasizes the absence of any IT-intera~tion.'~' The new series of compounds. [(x-Cp),Zr(OR),Cl, - ,,]( n = 1 or 2. R = Me. Et. or Pr') has been prepared. The reduction of dinitrogen by Na+ naphthalene- can be achieved in THF solution in the presence of [(x-Cp),Zr(OPr')CI] or [ (nCp),ZrCI,], and hydrolysis of the product affords ammonia.' 3 8

Oxygen Compounds.-Oxides, Mixed Oxides, Zirconates, Hafnates, and their Hydrates. The standard heat of formation of HfO, has been estimated as - 11 17.5 & 2.3 kJ mol- ' by determining the heat of combustion of hafnium metal.' 3 9 The formation. preparation. and properties of hydrous zirconia have been reviewedI4' and Zr0,.3.3H20. precipitated from a solution of ZrOC1, (2-6 mol 1- l ) , has been shown to contain both adsorbed and co-ordinated water molecules. 1 4 ' Metastable cubic and metastable tetragonal phases of ZrO, have been encountered during the dehydration of Zr(OH),, and the of the strucX-ray diffraction pattern of the former was r e ~ 0 r d e d . A I ~review ~ ture and properties of the polymorphs of ZrO,, and the phase equilibria and stabilization problems in the MgO-ZrO, and CaO-ZrO, systems, has been presented.' 43 Phase equilibria in the Y,O,-HfO, system have been investigated by X-ray diffraction at high temperatures and at low temperatures after annealing. '44 [ZrMo20,(OH),(H,0),] has been prepared by refluxing Zr(MoO,), gels in HCI { 1 4 mol- I ) and the crystals have been shown to contain cis-octahedral [MoO,(OH)H,O) and pentagonal-bipyramidal [Zr{03(OH)2)e,(02)ax] units, V. I. Kuleshov, E. M. Brainina, N. G . Bokii, and Yu. T. Struchkov, J . Organometallic Chem.,

lJS

1972,36,333. B. M. Kingston and M. F. Lappert, J . C . S . Dalton, 1972,69. K. W. Muir, J . Chem. SOC.( A ) , 1971, 2663. D. R. Gray and C. H. Brubaker, jun., Inory. Chem., 1971, 10, 2143. A. N . Kornilov and I. M.Ushakova, Doklady Akad. Nauk S.S.S.R., 1971,200, 1382. H. Th. Rinjten, 'Physical and Chemical Aspects of Adsorbents in Catalysis,' ed.. B. G. Linsem, Academic, London 1970, p. 315. A. Lesnikovich and V. V. Sviridov, Vesti Akad Nauk Belarus. S.S.R., Ser. khim. Nauk, 1971, 46. G. Katz, J . Amer. Ceram SOC.,1971, 54, 531. R. C. Garvie, 'High Temperature Oxides,' ed. A. M. Alper, Academic, New York, 1970, Vol. 2, p. 117. D. W. Stacey, US.Atomic Energy Commission, 1971, 1s-T-425 (Nuclear Sci. Abs., 1971, 25, 42883).

lJ6

13' 138 13'

140

14'

143

'41

23


with Zr-Oax = 208.8(5) pm and average Zr-Oen = 216.8 pm in the latter. One oxygen atom has an unusual environment in that it forms a three-way bridge in a planar [ZrOMo,] moiety.'45 The preparation and industrial application of zircon and zirconates have been reviewed,'46 as has the crystal chemistry of zirconian garnet.75The structure of a zircon from Kragero, Norway, has been determined. The principal structural unit is a chain of alternating edge-sharing SiO, tetrahedra and ZrO, trigonal dodecahedra, with Zr-0 bond lengths of 213.1 and 226.8 pm, the chains being joined laterally by edge-sharing ZrO, dodecahedra.147 The interactions of some sodium zirconosilicates with water under hydrothermal conditions have been studied and the hydrolysis products identified by their X-ray powder diffraction pattern^.'^' ZrO(H,PO,), and HfO(H,PO,), have been prepared by the reaction of H,PO, with the metal disilicide~.~' X-Ray diffraction studies have identified a distorted octahedral environment about zirconium in KZr,(P0,),,'49 and the structures of zirconium phosphates have been discussed in terms of their utility as chemical sieves.15' Some preparative and structural aspects of the normal sulphates of zirconium and hafnium have been r e v i e ~ e d ' ~and ' X-ray studies have shown that the sulphates Zr,O(SO,),,SH,O and Hf,0(S0,)3,5H,0 are isostructural and are more accurately represented as M,(OH)2(S04),,4H,0.'52 Other studies of zirconates and hafnates and related mixed oxide systems' are summarized in Table 2.

Table 2 Zirconates, hafnates, and related mixed oxide systems Compound

Source

Properties reported

Ref:

Sr2Hf04 Sr3Hf,07 Sr4Hf30,o

SrO-Hf02

X

U

Ba,ZrO, Ba3Zr,0,

BaO-ZrO,

X , isomorphous with Sr2Ti0, X, isomorphous with Sr,Ti,O,

b

(Ba,Sr)ZrO,

BaO + SrO + ZrO, 1500 "C/30 min

X,perovskite

C

PbZr( B 03)2

14' 146

14' 148

'41

Is 15*

+

+

PbO ZrO, B 2 0 3 identical with d (5 :5 :2) at 1250 "C PbO,ZrO,,B,.O, reported previously

A. Clearfield and R. H. Blessing, J . Znorg. Nuclear Chem., 1972,34, 2643. W. J. Baldwin, 'High Temperature Oxides', ed. A. M. Alper, Academic, New York, 1970, Vol. 2, p. 167. K. Robinson, G. V. Gibbs, andP. H. Ribbe, Amer. Mineral., 1971,56,782. K. V. Alyamovskaya and V. G. Chukhlantsev, Izvest. V. U . Z . , Khim. i khim. Tekhnol., 1971, 14, 827. D. N. Anderson, Dim. Abs. ( B ) , 1971, 32, 197. D. Leigh and A. Dyer, J . Znorg. Nuclear Chem., 1972, 34, 369. I. J. Bear and W. G. Mumme, Rev. Pure Appl. Chem., 1971,189. D. L. Rogachev, A. S. Antsyshkina, and M. A. Porai-Koshits, Zhur. strukt. Khim., 1972, 13,260.


24 Table 2-continued (CN3H6),[Zr(Co,)?],H.20 (CN,H6 = guanidinium) K3[Zr(OH)(C03),],3H20 Ca2ZrSi,0

Zr,P,O-

CaO- SiO ,-ZrO

ZrP,O,

X

Ref: e

X

f

A'

9

x

h

Properties reported

Source

Compound

+ TiP,O,

(1 : 1) 1580 "C/7 days: cpd. on surface of melt

BaZrPzO

BaCO, + ZrO, + 2(NH,)2HP0, 300 Cj24 h, then I 1 0 0 C sekeral days Hf(S0,),4H ,O -b MNO, H,SO, (1 :6:S)

Na4Hf(S0,),,3H,O K,Hf(SO,),.H 0 ( N H 4 12 Hf(S0,)3.2 H 2 0 M,[zr,o,(oH),(Hso,),(SO~)~],8H,O M,[Zr,O~~oH),(Hso,),(S0~)~].8H,O (M = Na or NH,)

,

ZrTiO, Hff i 0 , M,03.2Zr0, (MIii = lanthanide except Ce and Pm)

ZrO, + TiO, HfO, + TiO, ZrO(NO3j,,2H,O

+ M,O,

1

+

( 2 :1 ) in HNO,. then 4 0 0 SOO'C 10 h and 900- 1200 C/20 h

x

j

A', and reduction by CO and H,

k

m.p., X,fcc fluorite-type lattice

I

( u ) C. Delamarre and M. Perez y Jorba. Compt. rend, 1972, 274, C, 8. ( b ) P. Appendinco and G. Ramonda. Ann. Chim. (Italy), 1971,61, 61. (c) K. Noro, S . Shvaishi, M. Satoh, S . Masuyama, and M. Koizumi, Tokui Jigyo-sho, Doryoku-do, Kuku-nenryo Kuihatsu Jigyo-dun, 1970, N831-70-02, 46. ( d ) D. Schultze, 2. anorg. Chem., 1971,386, 277. ( e ) S. Voliotis, J. Faucherre, and J. Dervin, Compt. rend., 1972, 274, C, 1163. ( f ) T. D. Erickson, Diss. Abs. (B), 1971,32,455. ( g ) W. Gebert and 0. W. Florke, Naturwiss., 1972,59, 78. ( h )R. Masse and A. Durif, Compt. rend., 1972.274, C, 1692. (i) L. I. Fedoryako and I. A. Sheka, C'krain. khinz. Z h u r . , 1971,37,980. (j)T. 2. Maiskaya, N. S . Barsukova, L.B. Chistov, L. G . Nekhamkin, and L. M. Zaitsev, Zhur. neorg. Khim., 1971,16, 3260. ( k ) A. Kahn-Harari, Internat. Hautes Temp. Refract., 1971,8, 71. (0 K. I. Portnoi, N. I. Timofeeva, S. E. Salibekov, and I. V. Romanovich, Izrest. Akud. Nauk S . S . S . R . . Neorg. Materialy, 1972, 8, 406.

Complexes lvith Oxyanion Ligands. The zirconium-peroxo-oxalato-complex [Zr(0,)(C,0,)(H20),],3-4H20, has been assigned the trans-diaquo octahedral structure (28) from spectroscopic and thermal studies.' 5 3 The stability constants for [ZrO(C,0,)2]2- and [HfO(C,0,)2]2- in aqueous solutions of pH 4-5 have been calculated as 4.8 x lo8 and 3.3 x lo6, respectively.' 54 The precipitation from aqueous solutions of ZrOC1, and (NH,),C,O, has been investigated and evidence obtained for the soluble complexes [Zr(OH )2(C20,)2]2-.[(ZrO)2C20,]2 i , [Zr(OH)2(C20,)3]4-,and [Zr(C204)4]4 ,and theinsolublecornpoundsZr(C,O,),,.uH,Oand Zr(C,O&,Is3

'54

G. D. Gupta a n d G . V. Jere, IndiunJ. C h e m , (972, 10, 102. I . V. Pyatnitskii and T. I . Kravchenko, Ukrain. L h m Lhrr . 1971.37. 1054.


25

X Z ~ ( O H ) , , X H , O . ' [CO(NH,),],[Z~(C,~~)~],,~H~~, ~~ [Co(NH,),NO,],[Zr(C, 0,),],5H,O, and [ICo(NH,),CO,][Zr( C,0,),],5H20 have been prewith a salt of the pared by treating an aqueous solution of (NH,),[Zr(C,O,),] corresponding Co'"-ammine complex. Thermal decomposition of these complexes ( < 1 150 "C) afforded mixed oxides, no Co"'-zirconate being obtained.' 5 6

The reaction of ZrC1, with acetic acid has been investigated in several solvents and the highest yield of Zr(O,CMe), (86%) was obtained in CC1,.'57 Ionexchange studies have shown that, in HCl solutions (0.25 mol l-'), Zr" reacts with gluconic acid (HG) to give [Zr(OH),G] and [Zr(OH),(G),], which have Eight different stability constants of 4.0 x lo6 and 819 x lo5. re~pectively.'~~ crystalline zirconium oxychloride-D-gluconic acid complexes have been isolated from aqueous solutions containing ZrOC1, and 1,-gluconic acid.'" The stepwise stability constants of Zr'" complexes with aspartic and glutaric acids have been determined.16' The equilibrium formation constants for the 1: 1 complexes of Hf'" with glycine and serine in solutions of pH 2 have been determined as 31 and 18, respectively,'61 and the H f 0 2+-amygdalic acid complex, [HfO{PhCH(O)C O , ) , ] ' - , has been obtained in aqueous solutions of pH 7-10.5.162 The stability constants of the 1: 1 complexes of Z r 0 2 +with NN'-ethylenediarninebis(succinic acid) and NN'-ethylenediaminebis(g1utaric acid) have been determined.' HPv and Chromotrope 2R form a 1: 1 complex at pH 1-3 which has a free 0.4 kJ mol-' and Amax = 580 nm ( E = 7.13 x energy of formation -25.1 +

,

107.164 155

lS6 lS7

15* 159

160 16'

162 163 '64

H. Bilinski, B. Pokric, and Z. Pucar, J . Inorg. Nuclear Chem., 1971, 33, 3409. C. Gh. Macarovici and G. Schmidt, Rev. Roumaine Chim.. 1971,16,1759. Yu. A. Lysenko, V. L. Pavlov, and A. A. Kalinichenko, Zhur. neorg. Khim., 1971, 16, 2885. V. K. Zolotukhin, 0.M. Gnatyshin, and M. I. Koshik, Zhur. neorg. Khim., 1971, 16, 2550. C. G. Macarovici and L. Czegledi, Rev. Roumaine Chim., 1971, 16, 687. M. K. Singh and M. N. Srivastava, Talanta, 1972, 19, 699. S. S. Kalinina, Z. N. Prozorovskaya, L. N. Komissarova, and V. I. Spitsyn, Zhur. neorg. Khim., 1971, 16, 2547. I. V. Pyatnitskii and T. I. Kravchenko, Ukrain. khim. Zhur., 1971, 37, 1273. S. G . Tak. 0. P. Sunar, and C. P. Trivedi, J . Indian Chem. Soc., 1971,48,969. S. C. Dhupar, K. C. Srivastava, and S. K. Banerji, J . Indian Chem. SOC.,1971,48, 921.

26

Inorgunic Chemistrv of the Transition Elements

Complexes with 0 - D o n o r Ligands. ZrO(N0,),,2Bu,PO,, and HfOX,,2Bu,P04 (X = NO, or C1) have been identified as the species extracted by Bu,PO, from aqueous solutions acidified with HX.’65 The heats of formation of the l : l and l :2 adducts of the metal tetrachlorides with POCI, have been determined as - 72.0 + 5.4 and - 88.7 6.3 kJ mol- respectively, for ZrCl,, and -81.2 k 4.2 and -98.3 k 6.3 kJ mol-’, respectively, for HfC1,.83 The crystal structure of [ZrCI,(SOC1,)], (29) has been determined.166In the centrosymmetric dimer each Zr’” atom is bonded to two bridging chlorine atoms with Zr-Cl = 258( 1) prn, three terminal chlorine atoms with average Zr-CI = 234(2) pm, and the oxygen atom of a thionyl chloride molecule, Zr-0 = 227(1) pm.

+

’,

c1

Naphthaldehyde and furaldehyde (L) react with ZrC1, to give the ZrC14,2L adducts, whereas phthalaldehyde forms ZrCI,,L. These coloured compounds are non-electrolytes and appear to involve an octahedral ZrCl,O, chromop h ~ r eKojic . ~ ~ acid (30) and maltol (31) form 1 : 1 and 1:2 complexes with HftV 0

in perchloric acid solutions (1-2 moll- ’). The values of the stability constants, = 1.5 x 1013 (kojic acid, PI = 1.1 x 10l2 and p2 = 3.9 x loz2:maltol, /I1 and P2 = 3.0 x indicate a strong chelating ability of the o-hydroxyquinone group for Hrv.l6’ The interaction of Zrl” and HPV with some trihydroxyfluorones has been studied spectrophotometrically at various pH’s. ZrIV forms 1 :2 complexes with 9-salicylfluorone and p-dimethylamino165

166 167

N. Ichinose, Bunseki Kagaku, 1971, 20, 655; V. M. Klyuchikov, L. M. Zaitsev, S. S. Korovin, E. S. Solov’eva, and I. A. Apraskin, Zhur. neorg. Khim.,1972,17, 780. R. K. Collins and M. G. B. Drew,J. Chem. Soc. ( A ) , 1971,3610. J. Hala and J. Smola, J. Inorg. Nuclear Chem., 1972, 34, 1039.


27

phenylfluorone which absorb strongly at 450460 nm (c = 3.8 x lo4 and 1.3 x lo4, respectively), and HPV forms 1:2 complexes with 9-salicylfluorone and phenylfluorone which have A,, = 520 ( E = 2.9 x lo4) and 510 nm ( E = 2.7 x lo4),respectively.'68 The extraction of Zr" from an iodide system with diantipyrinylmethane (L)has been shown to involve the formation of ZrI,L,.'69 [Zr{CF,C(O)CHC(O)CF,},] and [Hf{ CF,C(O)CHC(O)CF,},] have been prepared by treating ZrCl, or HfCI, in carbon tetrachloride solution with CF,C(O)CH,C(O)CF, under refluxing conditions with exclusion of oxygen.170 Thenoyltrifluoroacetone (HA) extracts zirconium from perchloric and nitric acid solutions by the formation of Zr(A),ClO,, Zr(A),NO,, or Zr(A), complexes which have formation constants of 4 x lo8, 9.6 x lo7,and 6 x lo4, re~pectively.'~~ The successive stability constants for complexes of ZrIV with benzoyltrifluoroacetone and l-phenyl-3-methyl-4-benzoyl-5-pyrazolone have been calculated by examination of the distribution between benzene and aqueous phases.'72 Zr(OPr'),,Pr'OH reacts with bis(acetoacetates) [MeCOCH,C(0)O],(CH,)n (A; n = 2,4, or 5 ) to form [Zrz(OPri)6(A)], [Zr(OPr'),(A)], or [Zr,(OPr'),(A),], depending upon the stoicheiometric ratio of the reactants.173The reactions of zirconium alkoxides with tri-t-butoxysilanol under reflux in benzene solution have been studied. Tetra-alkoxides, Zr(OR), afford [(Bu'O),S~O]~Z~(OR)~ -n ( n = 2 or 4), whereas Zr(OR),(acac), give [{(Bu'O),SiO},Zr(acac),] or [Zr(acac),O(Bu'O), SiO],.' 74 The volatile double alkoxides MHf,(OR),, M2Hf(OR),, ( M = Li, Na, or K; R = Et or Pr'), KHf(OBu'),, [HfM(OPr'),],, and HfM,(OPri),o (M = A1 or Ga) have been synthesized. Hf(OR), react with MOR (M = Li, Na, or K) in 2: 1 and 1 : 1 molar ratios to form MHf,(OR), and M2Hf,(OR),, respectively. The compounds sublime at 180-200°C and 0.5 mmHg and are covalent monomers in benzene solution. Both KHf,(OPr'), and K,Hf3(0Pr'),, exchange all their alkoxy-groups when treated with excess n-butanol; however, only partial exchange is achieved with t-butyl alcohol and KHf,(OPr'),(OBu'), and K,Hf,(OPr'),(OBu'), are obtained. Hf(OBu'), reacts with KOBu' (2: 1 or 1: 1)to give the volatile KHf(OBu'), which shows an average association of 1.5 in benzene. The reaction of Hf(OPr'), with M(OPr'), (M = A1 or Ga) in 2: 1 and 1:4 ratios affords HfM(OPr'), and HfAl,(OPr'),,, respectively. The i.r. and n.m.r. spectra of all these volatile double alkoxides were reported.' 75 168

0.A. Tataev and V. K. Guslinov, Zhur. analit. Khim.. 1971,26,829; 0 .V. Mandzhgaladze and V. A. Nazarenko, ibid., p. 833. V. P. Zhivopistsev, B. I. Petrov, and A. Rudakova, Uch. Zap. Permsk. Gos. Univ., 1970, No. 207, 201. 170 S. C. Chattoraj, C. T. Lynch, and K. Mazdiyasni, U S . P., 3634477. 17 1 A. S. Solovkin and A. I. Ivantsov, Zhur. neorg. Khim., 1971, 16, 2247. 172 G. P. Ozerova, N. V. Mel'chakova, and V. M. Peshkova, Vestnik Moskov. Univ. Khim., 1971, 12,367. 173 U. B. Saxena, A. K. Rai, and R. C. Mehrotra, Indian J. Chem., 1971,9,709. 174 Y . Abe, K. Hayama, and I. Kijima, Bull. Chem. SOC.Japan. 1972,45,1258. 175 R . C . Mehrotra and A. Mehrotra, J . C.S. Dalton, 1972, 1203. 169

28


Sulphur, Selenium, and Tellurium Compounds.-The crystal structure of the metal-rich zirconium sulphide Zr,S, has been determined and each sulphur atom shown to be at the centre of a square antiprism of zirconium atoms.'76 The reaction of ZrS, with potassium in liquid ammonia has been shown to give four K,ZrS, phases (.u = 1, 0.86, 0.71, or 0 . 7 1 4 . 2 2 ) which differ in the nature of the co-ordination sites occupied by the potassium atoms between the ZrS, 1 a ~ e r s . ZrC1, l ~ ~ reacts with NaS,P(OEt), in toluene to form [Zr{S,P(OEt),},], which appears to involve a trigonal-dodecahedra1 arrangement of sulphur atoms about the The non-stoicheiometric zirconium silicoselenide, Z r 2 ~ o o S i l ~ 9 0 S ehas l~99 been studied crystallographically.' 7 9 The phase Zr,Te, has been characterized in the zirconium-rich region of the zirconium-tellurium system and the phases Hf,+,Te, (0.25 6 t d 0.431, HfTe,, and HfTe, have been identified in the tellurium-rich region of the hafnium-tellurium system."' Nitrogen Compounds.-The formation of ZrN .9 by a new method of evaporation synthesis has been de~cribed.~' The compound LiZrN, has been prepared from Li,N and ZrN,,,,, and X-ray crystallographic studies have shown that the crystals contain hexagonally close-packed nitride ions, with ZriV and Lil ions in octahedral and tetrahedral holes, respectively.' 8' ZrCl,,CCI ,CN and ZrCI,.CH,CICN have been prepared from ZrC1, and the corresponding chlorinated nitrile: the former has been shown to be isomorphous with TiCl,,CCl,CN, and is thus a chloride-bridged dimer, with each Zr" octahedrally ~o-ordinated.~' The reaction of Zr(OPr'), with the Schiff bases acetylacetone-2-hydroxyalkylimine, N-[(3-hydroxy-2-naphthyl)methylene]-2-hydroxyalkylamine,and o-hydroxyacetophenone-2-hydroxyalkylimine (HL) affords the polymeric Zr(OPr'),L and ZrL, compounds. N.m.r. and i.r. spectral studies indicated that the N atom of the Schiff base is co-ordinated in these corn pound^.^^ The stepwise stability constants for zirconium and hafnium thiocyanatocomplexes have been determined by solvent-extraction techniques. The values B1 = 12.1 k 2.2. p, = 215 & 11, /j4 = 205 k 20 for zirconium, and p1 = 13.5 3.3, p2 = 215 k 17, and /?, = 167 5 28 for hafnium were obtained.'82 The 8, value for ZrlV-SCN- has also been evaluated as 11.5 T 1 and the A,,, of the corresponding complex observed at 270 nm.183 [Hf(OH)(NCS),],6THF has been identified as the species extracted into T H F from aqueous solutions of HP' and HSCN ( 60.5 mol and [Zr(OH),(NCS),],2L and [Hf(OH),(NCS),],2L (L = tri-n-butylphosphate, di-isoamylmethylphosphonate, or tri176

17'

"'

H.-Y. Cheng and H . F. Franzen, Acta Cryst., 1972, BZS, 1399. J. Rouxel, J. Cousseau, and L. Trichet, Compt. rend., 273, C , 243. R. N. McGinnis and J. B. Hamilton, Inorg. Nuclear Chem. Letters, 1972,8,245. Y. Jeanin and A. Mosset, J . Less-Common Metals. 1972, 27, 237. L. Brattas and A. Kjekshus, Acra Chem. Scand., 1971, 25, 2350, 2783. A. P. Palisaar and R. Juza, Z . anorg. Chem.. 1971, 384,1 . A. E. Laubscher and K. F. Fouche, J . Inorg. Nuclear Chem., 1971,33,3521. S. Tribalat and L. Schriver, Compt. rend., 1972, 214, C, 849. I. V. Vinarov, N. F. Rusin, and L. I . Il'chenko, Zhur. neorg. Khim., 1971, 16,2226.


29

octylphosphine oxide) have been obtained in extractions from aqueous solutions by an organic solution of the organophosphorus compound.185 Conductometric and spectrometric evidence for 1:2, 1:4, and 1:6 Zr'"SCN- and Zr"-SeCNcomplexes has been obtained by studying the reaction of ZrC1, with KSCN and KSeCN.58 [ZrCl,(NCSe),], [HfCI,(NCSe),], K,[Zr(NCSe),], and K,[Hf(NCSe),] have also been identified in similar studies. Stabilization of the metal-selenocyanate bond by chelating ligands allowed [Zr( bipy),(NCSe),], [Hf(bipy),( NCSe),], [Zr(phen),(NCSe),] ,THF, and [Hf(phen),(NCSe),],THF to be synthesized.lB6

Halogen Compounds.-A text describing the chemistry of fluoride compounds of zirconium and hafnium has been pub1i~hed.l~' Binary Compounds. The thermodynamics of the formation of HfCl,, and of HfCI,, in fused sodium and potassium chlorides have been described.IB8The reduction of ZrX, (X = CI. Br, or I) with metallic Zr or A1 in molten AlCI, has been studied at temperatures from 250 to 360°C, depending on the halide. The electronic spectra of the initial reaction products were consistent with either a solvated Zr"' complex or an intervalence Zrll'-Zrlv species. Further reduction resulted in the precipitation of reduction products which were identified by analysis and i.r., electronic, and X-ray powder diffraction spectra. The stability of the trihalides with respect to disproportionation was observed to increase from chloride to iodide: thus ZrCl, and ZrC1,,0.4AIC13 were precipitated, whereas only ZrI, was formed.'89 Metathetical exchange of BBr, with anhydrous ZrC1, and HfCl, has been shown to be a convenient route to the corresponding tetrabromides. ZrBr, was also obtained from the reaction of BBr, with ZrO2.l7 Although ZrX, and HfX, (X = Cl, Br, or I) are polymeric in the solid state, Raman studies have shown that the compounds exist as tetrahedral monomeric molecules in the vapour phase. Force constants and some thermodynamic functions have been calculated for these molecules, values of the former being virtually independent of the metal but decreasing as C1 > Br > I.,' Fluoro-complexes. The double fluorides M,ZrF, (M = Na or K) have been obtained by sintering M,SiF, with anhydrous ZrCl,.' Rb,Zr,F,, contains four crystallographically independent Zr" atoms, each of which has a different co-ordination geometry. The structure consists of cross-linked polyhedra which involve six-co-ordinate octahedral, seven-co-ordinate pentagonalbipyramidal, and irregular antiprismatic environments about the zirconium, with Zr-F bonds of length 190-224(2) pm.Ig1 The Mossbauer spectra of

190 '91

0. A. Sinegribova and G. A. Yagodin, Zhur. neorg. Khim., 1971, 16,2237. A. M. Golub, T. P. Lishko, and V. V. Skopenko, Ukrain. khim.Zhur., 1971,37, 835. M. M. Godneva and D. L. Motov, 'The Chemistry of Fluoride Compounds of Zirconium and and Hafnium', Nauka, Leningrad, Otd: Leningrad, U.S.S.R., 1971. M. V. Smirnov, T. A. Puzanova, N. A. Loginov, V. A. Panishev, and B. G. Rossokhin, Re$ Zhur. Khim., 1970, Abs. No. 14B824. J. W. Moyer, Diss. Abs. ( B ) , 1971,31,7169. S. M. Flaks, U.S.S.R.P. 311865 (Cl. CO1 6d) 1971. G . Brunton, Acta Cryst., 1971, B27, 1944.

30


178Hfin polycrystalline M2HfF6 and M,HrF, (M = Li, Na, K, Rb, Cs, or NH,) have been measured at 4.2K using the 93 keV emission from a 178W source in tungsten MiM2ZrOF, (M'. M2 = K. Rb. Cs, T1) have been prepared by heating M'F. MLF,and ZrOF, (2: 1: 1) at 5 0 0 4 0 0 "C under an atmosphere of dry n i t r ~ g e n . " ~The compounds of the TIF-ZrF, and T1FHfF, systems. TIMF,, TI, hhMFfi,h6, TI,MF,. and Tl,MF7 (M = Zr or Hf). have been characterized by X-ray diffraction studies and their melting points r e p ~ r t e d . ' ~ Sn,ZrF8, , which is useful for reducing the solubility of dental enamel, has been prepared by the reaction of SnF, and ZrF, either in aqueous solution (1 :2) or in a melt (2: AgZrF, and AgHfF, have been prepared by heating Ag,SO, and a complex halide of the appropriate metal in a stream of fluorine at 480°C. E.s.r. and diffuse reflectance spectra indicate that these compounds contain Ag" in a tetragonally distorted ( c > a ) octahedral environment.lY6 The hydrated double fluorides of hafnium, MHfF,,6H20 (M = Fe, Co, Ni, or Zn), MnHfF6,5H,0, CuHfF6,4H,O, and M,Hff8,12H,0 (M = Co, Ni, Cu, or Zn) have been synthesiied and shown to be isostructural with their zirconium analogue^.'^^ Rare-earth fluorozirconates, LnZrF, (Ln = lanthanide or Y) have been prepared and characterized by X-ray studies.' 9 8 Chloro-, Bromo-, and lodo-complexes. The effect of pressure on the kinetics of the reaction between solid NaCl and ZrC1, or HfC1, vapours has been investigated.'99 The i.r. and Raman spectra of solid ZrC1,,2NOCl and HfC1,,2NOCl have shown that they consist of NO' and octahedral hexachlorometallate ions.200 Normal-co-ordinate analyses have been reported for the [ZrX,I2and [HfX,I2- ions (X = C1 or Br).'', ZrI, vapour reacts rapidly and reversibly with metallic copper and silver which are (M) at ca. 200°C to give thick, velvet-like scales of Mo,25Zro.7513, considered to be pseudo-trihalides. Hfl, vapour only reacts to a small extent with copper acd not at all with silver.20'

b r i d e s and Tetrahydroborate Compounds.-ZrB,, HfB,, and the mixed diboride TiB,-ZrR, have been prepared by heating a stoicheiometric mixture of boron and the metal dioxides (1600-1900'C; lo-, mmHg).24The phases of the Hf-B202 and IIf-M-B (M = Mo or W)203 systems have been studied by X-ray diffract ion techniques . 193

19'

lg6 19'

19' 199

2oo '01 *02

E. Gerdau, B. Scharnberg, and H. Winkler, Conference on Hyperfine Interactions in Excited Nuclear Processes 1970, 3, 861. A. Vedrine, D. Belin, and J. P. Besse, Bull. SOC.chim. France, 1972, 76. D. Avignant and J. C. Couseins, Compt. rend., 1972, 274, C , 631. J. D. Donaldson, U.S.P., 3594116 (C1. 23-20: C 22b), 1971. G. C. Allen, R. F. McMeeking, R. Hoppe, and B. Miiller, J.C.S. Chem. Comm., 1972, 291. R. L. Davidovich, T. F. Levchishina, and T. A. Kaidalova, Izvest. Akad. Nauk S.S.S.R., Neorg. Materialy, 1971, 7 1992. M. Poulain, M.Poulain, and J. Lucas, Materials Res. Bull., 1972, 7 , 319. P. Pint and S. N. Flengas, Canad. J. Chem., 1971,49,2885. J. MacCordick, C. Devin, R. Perrot, and R. Rohmer, Compt. rend., 1972, 274, C, 278. K. Lascelles and R. A. J. Shelton, J. Less-Common Metals, 1971, 25, 49, K. I. Portnoi, V. M. Romashov, I. V. Romanovich, Yu.V. Levinskii, and S. A. Prokofev, Zzvest. Akad. Nauk S.S.S.R., Neorg. Materialy, 1971, 7. 1987.


31

The kinetic parameters of the heterogeneous thermal decomposition (200300 "C) of Zr(BH,), and Hf(BH,), to ZrB, or HfB,, respectively, B,H,, and H, have beendeterrni11ed.2'~R,NBH,(R = alky1)reactwith Zr(BH,),and Hf(BH,), to form the thermally stable (R,N)[Zr(BH,),] or (R,N)[Hf(BH,)J. The corresponding lithium salts may be obtained in a similar manner, although they decompose to the borohydride compounds in vacuo at low temperatures. The "B n.m.r. and i.r. spectra of these compounds indicate that the tetrahydroThe Raman borate groups are bonded to the metal via two h~dr0gen-bridges.l~~ spectrum of Zr(BH,), has been reported and assigned on the basis of molecular symmetry,205 and the mass spectrum of this compound (at 70 eV) afforded Zr(BH,)i as the main component.206 The 'H n.m.r. spectra of Zr(BH,), and Hf(BH,), have been found to have the same temperature dependence and this has been attributed to loB and "B quadrupolar spinlattice relaxation effects. The activation energy for molecular reorientation, 13.0 & 0.4 kJmol-',is thesameforboth molecules withinexperimentalerr~r.~" Carbon, Silicon, or Germanium Compounds.-The chemical stability of the germanides Zr,Ge. Zr,Ge,, ZrGe. ZrGe,. Hf,Ge,, and HfGe, towards mineral and organic acids and oxidizing and complexing agents has been found to increase with increasing germanium content.28 Alkyl and Related Compounds. The alkylzirconium trihalides, RZrX, (R = Me, Et, or Pr: X = C1 o r Br) have been prepared by treating ZrX, with R,Zn in toluene at 0 "C; the dialkylzirconium dihalides, R,ZrX, (R = Me or Et; X = C1 or Br) were obtained from these reactants in pyridine at 0°C. R,ZrX,,bipy adducts were also obtained.208 Tetra-(1-norbornyl)-zirconium and -hafnium have been prepared5 by treating (1-norborny1)lithium with ZrC1,,2Et,O or HfC1,,3Et,O, respectively, and tetraneopentylzirconium was obtained in a similar manner., The synthesis of tetrabenzylhafnium has been achieved by the addition of HfCl, to BzMgCl in ether. Adduct formation ofthe compound with py, bipy, quinoline, Me,P, and T H F was studied using n.m.r. spectroscopy, and the equilibrium constant for Bz,M + py + Bz,M,py was determined as 12.6 k 0.6 for M = Zr, and as 460 f 50 for M = Hf.'09 A determination of the crystal structure of tetrabenzylhafnium at -40°C has shown the molecules to be isostructural with tetrabenzylzirconium and thus to involve some n-interaction between the aromatic ring and the metal d-orbitals, in addition to the four Hf-C o-bonds.,

Cyclopentadienyl Compounds. [(n-Cp),Zr(Bz),] has been prepared in 60 % yield by the reaction of [(n-Cp),ZrCl,] with BzMgCl in ether. The compound P. Rogl, H. Nowotny, and F. Benesovsky, Monatsh.. 1971, 102,971. V. A. Grigor'ev, Kinetika i Kataliz, 1971, 12, 1042. '05 B. E.Smith and B. D. James, Inorg. Nuclear Chem. Letters, 1971, 7. 857. ' 0 6 Yu.S. Khodeev and B. M. Kirin, Zhur. strukt. Khim., 1971,12,531. *07 T. J. Marks and L. A. Shimp, J . Amer. Chem. SOC.1972,94,1542. ' 0 8 K. H. Thiele and J. Kruger, Z . anorg. Chem., 1971,383,272; K. H. Thiele, J. Miiller, K. Jacob, S. Schroder, E. Anton, and H. D. Lehmann, Ger. (East) P., 76673 (CI. C. 070, 1970. '09 J. J. Felten and W. P. Anderson, J . Organometallic Chem., 1972,36,87. '03

'04


32

may be recrystallized from boiling heptane as yellow needles, and thus shows unexpected thermal stability. Unlike its titanium analogue, [(n-Cp),Zr(Bz),] does not react with carbon monoxide, even at 40atm and 100°C.''4b Sulphur dioxide has been shown to insert into Zr-alkyl bonds and also into the Zrcyclopentadienyl rc-bond in certain cases. The preparation of the 0-sulphinatoderivatives, [(n-Cp)(C,H,SO,)Zr(O,SMe)Cl],,, [n-Cp)(C,H,S02)ZrO]n, and [ ( T ~ - C ~ ) ( C ~ H ~ S O , ) Zwas ~ S Oachieved ~ ] ~ , in this way. Insertion uf SOz into the 'ionic' (n-Cp)-Zr bond in these compounds parallels the path of reaction with EtOH or MeC0,H. It was not possible to insert SO, into the other (n-Cp)-Zr bond.' Insertion reactions of sulphur dioxide between both Zr-Me bonds and one (n-Cp)-Zr bond in [(rc-Cp),ZrMe,] have also been reported. Nitric oxide will insert into a Zr-Me bond of this compound leading to the novel zirconium complex (32), a methylnitrosohydroxylamine derivative.

Insertion reactions of sulphur dioxide and nitric oxide have also been observed lo with [(rc-Cp),Zr(Cl)Me] and [(~c-Cp),Zr(Cp)].~ The X-ray determination of crystal structure of tetracyclopentadienylhafnium has established that the molecule should be represented as C(7c-c~)~Hf(Cp),], and thus resembles the titanium rather than the zirconium analogue.' 3 5 Both [(n-Cp),Hf(Cp),] and [(x-Cp),Zr(Cp)] exchange nonequivalent cyclopentadienyl rings very easily such that, even at - 15OoC,only one sharp line is observed in the 'H n.m.r. spectrum.'' The crystal and molecular structures of [(x-Cp),ZrF,] and [(n-Cp),ZrI,] have been determined. Both molecules have the expected distorted tetrahedral arrangements of two (n-Cp) groups and two halide atoms about the metal. The Zr-F bond, 198 pm, is considerably shorter than expected from the length of the Zr-I bond, 285 pm, and it is suggested that the contraction is a consequence of the marked ionic character of the bond, rather than Zr-F 71bonding.2' A new series of zirconium compounds [(n-Cp),Zr(OR),Cl, - ,,I (n = 1 or 2: R = Me, Et, or Pr') has been prepared by allowing the appropriate alcohol and triethylamine to react with [(n-Cp),ZrCl,] in THF. Hydrolysis of the [I(x-Cp),Zr(OR)Cl] compounds affords the corresponding [ClZr(n-Cp),OZr(rc-Cp),Cl] derivative, whereas the [(n-Cp),Zr(OR),] compounds are hydrolysed to polymeric species, with the cyclopentadienyl groups being

'

'lo

P. C. Wailes, H. Weigold, and A. P.Bell, J . Organometallic Chem., 1972, 34, 155. G . A. Sim and M . A. Bush,J. Chem. SOC.( A ) . 1971, 2225.


33

displaced in the final stages. Of these compounds, only [(n-Cp),Zr(OPr')CI] was found capable of activating molecular nitrogen to produce ammonia.'38 The stable complexes [(n-Cp),M1(C1)M2Ph3] (M' = Zr or Hf; M2 = Si or Ge) have been prepared by salt-elimination reactions between [(n-Cp),M 'Cl,] and Ph,M2Li(Na). Some evidence was also obtained for the formation of [(n-Cp),Zr(SnPh,),].' 3 6 These complexes involve a metal-metal bond which cannot have any 7c-contribution, as manifested by the long Zr-Si separation of 281.3(2) pm in [ ( ~ - C p ) , Z r C l S i P h ~ l[(x-Cp),ZrX,] .~~~ (X = C1 or Br) react with M2P,Ph, (M = Li or Na) in dioxan to form the orange bis-(xcyclopentadienyl)-(1,2,3-triphenylphosphanato-P',P3)zirconium, which has a four-membered ZrP, ring [see (26)].126 The interaction of [(n-Cp),MCl,] (M = Zr or Hf) with a P-diketone (HL) in the presence of triethylamine has been shown to give either [(n-Cp)MClL,] or [(n-Cp)ML,], depending on the ratio of reactants and the nature of the P-diketone. In this way [(n-Cp)MClL2] (M = Zr or Hf; HL = acac, bzac, or 1,3-diphenyl-1,3-dione and [(x-Cp)ML,] (M = Zr or Hf; H L = tropolone, acac, or 1,3-diphenyl-1,3-dione) have been prepared. Variable-temperature 'H n.m.r. studies have indicated that these [(n-Cp),-MCIL,] compounds exist predominantly as cis-isomers in solution but that they lack stereochemical rigidity.'28, 2 1 3 Vanadium

Introduction.-Texts describing the high-temperature electrochemistry and physical chemistry of vanadium" and oxygen compounds of this element2', have been published, and the compilation of the chemistry of organovanadium compounds has been Interesting developments in vanadium chemistry this year include the preparation of the dioxodihalogenovanadate(v)anions, [VOJ,] - (X = F or C1) which are isoelectronic with the corresponding Cr02X2species.216A new class of vanadium compounds, the golden-yellow pentachloroalkoxyvanadatediv), [V(OR)C1,]2-, has been characterized.,' Crystals of tetrakis(dithioacetato)vanadium(rv), [V( MeCS,),], involve two trigonal-dodecahedra1 VS, chromophores, one where the ligands chelate the four m-edges and the other where they chelate over two m- and two g-edges of the dodecahedron. This latter appears to be the first example of such an arrangement.,18 The new 212

213

21*

215

216

217

218

D

M. Kh. Minacheva, L. A . Fedorov, E. M. Brainina, and R. Kh. Freidlina, Doklady Akad. Nauk S.S.S.R., 1971, 200, 589; L. A. Fedorov, M. Kh. Minacheva, and E. M. Brainina, Izvest. Akad. Nauk S.S.S.R., Ser. khim., 1971, 1844. V. V. Voleinik, 'High Temperature Electrochemistry and Physical Chemistry of Vanadium', Nauka, S.S.R., Alma, Ata, U.S.S.R., 1971. A. A. Fotiev, M. P. Glazynin, V. L. Volkov, B. G . Golovkin, and V. A. Makarov, 'Studies of Oxygen Compounds of Vanadium', Sverdlovsk, U.S.S.R., 1971. Gmelin, 'Organovanadium Compounds', Handbook of Inorganic Chemistry, Supplementary Work, Vol. 2, Gmelin Institute, 1971, 8th edn. (a) E. Ahlborn, E. Diemann, and A. Muller, J.C.S. Chem. Comm., 1972,378; (b)A. K. Sengupta, and B. B. Bhaunik, Z. anorg. Chem., 1971, 384,255. R. D. Bereman, Diss.Abs. (B), 1970, 31, 1132. L. Fanfani, A. Nunzi, P. F. Zanazzi, and A, R. Zanzari, Acta Cryst., 1972, B28,1298.


34

vanadium(rv) compounds which involve four V-C a-bonds, tetrabenzylhave been reported. vanadium’ and tetra-(l-norbornyl)~anadium,~ The results of kinetic studies of the reaction between [V(salen)]+ and oxygen in pyridine indicate that a [V(salen)]+-oxygen adduct is formed, and thus reinforce the view that V”’-complexes can act as oxygen carriers.220 Cyanocomplexes of vanadium-(Ir) and -(I), [V(CN),]4‘5-, have been obtained by reduction of the corresponding vanadium(ili) complex by potassium in liquid ammonia.221The existence of [V(CN),NO]’ - has, however, been challenged on experimental and theoretical grounds.222 Direct ligand substitution in [V(CO),]- by photolysis has been reported, and the synthesis of several [V(CO,L]- and [V(CO),L,]- complexes achieved in this manner.223 Carbonyl, Cyanide, and Nitrosyl Complexes.-There have been conflicting reports concerning the utility of photochemical substitution for ligand substitution reactions of [v(co),]-. Although [V(CO),(MeTHF)]- was generated by the irradiation of a glass (90 K) of [Na(diglyme),] [v(co)6]dissolved in 2-methyltetrahydrofuran, the substitution process rapidly reversed when the glass was allowed to warm to room temperature. Similarly, irradiation of a solution of [V(CO),]- in MeTHF at room temperature in the presence of PPh, was found to produce no net reaction in a sealed vessel; however, when CO evolution was allowed, a pale, air-sensitive material was obtained which did not contain [V(CO),PPh3]-.223a However, photolytic substitution has been reported as the best available method for the preparation of phosphine-, arsine-, and stibine-substituted carbonyl anions of vanadium, and the Et,N+ salts of [V(CO),L]- [L = Ph,P, Bu,P, Ph2PCH2CH2PPh2,Ph,As, (Ph2AcC,H,),Fe, or Ph,Sb] have been obtained in good yield.223bThe reasons for this discrepancy are not clear. Photolysis of M[V(CO),] (M = Na or Et,N) in the presence of cyanide yields Na,[V(CO),CN], or with simultaneous photochemical oxidation of vanadium, (Et,N),[V(CO),(CN)2]2. In liquid ammonia, photolysis of Na[V(CO),] affords Na[V(CO),NH,]. These complexes have been characterized by i.r., electronic, and ” V n.m.r. spectra, and structure (33) was suggested for the vanadium(0) anion.223c 0

0

NC -

0 219 220 22 1

222

223

(33)

0

J. D. Ibekwe, and J. Myatt, J . Organometullic Chem., 1971, 31, C65. J. H. Swinehart, Chem. Comm., 1971, 1443. R . Nast and D. Rehder, Chem. Ber., 1971, 104, 1709. (a) J. Masek and R. Pribil, jun., Znorg. Chim. Acta, 1971, 5, 499; (b) R. F. Fenske and R. L. DeKock, Znorg. Chem., 1972, 11,437. (a)P. S. Braterman and A. Fullarton, J . Orgunometullic Chem., 1971, 31, C27; (b) A. Davison and J. E. Ellis, ibid., p. 239; (c) D. Rehder, ibid., 1972, 37,303.


35

[R,MV(CO),PPh, J have been prepared by the reaction of [v(co),]-salts with R,MCI. The substituted complexes are very prone to heterolytic cleavage in weak donor solvents, and reactions of some of these tin compounds are included in Scheme 2, which describes convenient syntheses of [HV(CO),(diphos)], [IV(CO),(diphos)], and [V ( C O ) , ( d i p h ~ s ) ] . ~ ~ ~ The seven-co-ordinate complexes [R,MV(C0)6],

(R,M = Ph,Sn, EtHg, or Ph,PAu), and [Ph,SnV(CO),(diphos)]

\

-[Ph,SnV(CO),] diphos [Ph,SnV(CO),(diphos)]

Ph SnCl

(Et.aN)CV(CO),I

diphos hv

Ph/

\\

(Et,N)[V(CO),(diphos)] Me3/

TgBF4,

(Ph,As)[HCI,

12,

CHZCI,

- 60°C

Scheme 2

The reaction of [ (n-Cp)V(CO)] with N-piperido(dialky1aminodifluorophosphine), C,H ,NPF,, in boiling toluene gives [(n-Cp)V(CO),(PF,NC,H,,)], which has v(C-0) stretching frequencies at 1925 and 1842 cm-'. These values are higher than those of the corresponding Bu,P derivative, consistent with the greater n-acceptor strength of the difluorophosphine K,[V(CN),] and Na,[V(CN),], prepared by the reaction of V(CH,CO,), with KCN and NaCN, respectively, have been quantitatively reduced by potassium in liquid ammonia to K,[V(CN),], and then to K,[V(CN),]. The i.r. spectra and the magnetic susceptibilities (9-295 K) of these new cyanide complexes of vanadium-(Ii) and -(I) were obtained.221 The purported existence of the [V(CN),N0]5 - ion has been questioned. The electrode potentials relevant to the only preparative method described for this ion, the alkaline reduction of metavanadate by hydroxylamine in the presence of excess cyanide, suggest that no reaction should occur. This seems to be correct, 224 225

A. Davison and J. E.Ellis, J . Organometallic Chem., 1972, 36, 113, 131. R. B. King, W. C. Zipperer, and M. Ishaq, Inorg. Chem., 1972, 11, 1361.

36

Inorgunic Chemistry of the Transition Elements

since the 'product' of such a reaction exhibits the polarographic behaviour of metavanadate., 2 2 a The existence of [ V ( C N ) , N 0 I 5 - has also been questioned on the basis of MO calculations.222b

Simple Binary and Related Compounds.-Oxides. The information presently available concerning the crystal structures and properties of vanadium oxides has been tabulated.226 A phase diagram has been proposed for the V-VO system from m.p., d.t.a., X-ray. and other studies. In this system V,O,, V,O, and V,O have been identified at 510, 1 185. and 1665' C . respecti] ely. and the m.p. of V O was determined as 1790 . 2 2 7 The cubic vanadium monoxide phase has been shown228to exhibit 91 and V O l ~ 0 5 - V O l ~ 2 5 . two closely related phase sections. VO,,,,-VOo The formation of gaseous V O by the flash photolysis of VOCl, has been reported. and some new transitions have been identified in the electronic absorption spectrum of this Studies of the V,O3-V,O, system have confirmed that the phases V,O,,(n = 2-9) exist below 1400°C.230The crystal structure of V , 0 7 has been shown to be based on the rutile lattice, the VO, octahedra being considerably distorted with V-0 = 178-212 pm.231The heat and entropy of formation of V,O, at 1333 K have been determined as -373 kJ mol-' and 146 J mol-' K - respectively, by electrochemical rnea~urements.'~ A refinement of the crystal structure of V,OI3 has shown that the structure proposed by Aebi (1948) is correct. The V-0 distances in the distorted VO, octahedra range from 164.2 to 227.6(3) pm.232The i.r. spectra of V 2 0 3 , V 2 0 4 , and V,O, have been redetermined and to be quite different from those reported earlier, which have been used in discussions of the catalytic behaviour of these oxides. An effusion-mass spectral study of the vapours in equilibrium with V 2 0 3 . V 2 0 , , and V,O, at elevated temperatures has been reported. The vapour over V,O, at 1000-1200 K contains V,O,, and V,O, with standard heats of formation of -2560 _+ 30 and -2490 _+ 30 kJ mol-', respectively. V 2 0 , decomposes rapidly, at similar temperatures, to V203(s),V02(g),and presumably O,(g). At 2270 K. the vapour over V,O, contains V(g). VO(g). and VO,(g), the oxides having standard heats of formation of 147 _+ 17 and -226 & 17 kJ mol-', respectively.234The standard free-energy change for the reaction 2VO,(s) + )O,(g) --* V,0,(1) has been reported as -74.5 k 0.032 kJ mo1-l at 1020-1 100 K . 2 3 5 The crystal orientation dependence of the K and L X-ray emission lines of

,

226 227 228 229

230

231 232

233 234

235

M. Neuberger, Gov. Report Announce. ( U . S . ) . 1972,72, 204. D. G. Alexander, and 0. N. Carlson, Met. Trans., 1971, 2, 2805. H. Reuther and G. Brauer, 2.anorg. Chem., 1971,384,155. A. G. Briggs and R. J. Kemp, J.C.S. Dalton, 1972, 1223. S. Kachi, T. Takada, Y. Bando, K. Kosuge, H. Okinaka, and K. Nagasawa, Proceedings of the International Conference on Ferrites, 1970, 563. H. Horiuchi, M. Tokonami, N . Morimoto, and K. Nagasawa, Acta Crysz., 1972, B28, 1404. K. A. Wilhelmi, K. Waltersson, and L. Killborg, Acia Chem. Scand., 1971, 25, 2675. G. Fabbri and P.Baraldi, Analyt. Chem., 1972,44, 1325. M. Farber, 0. M. Uy, and R. D. Srivastava, J. Chem. Phys., 1972,56,5312. H. Suito and D. R. Gaskell, Met. Trans., 1971, 2, 3299.


37

atoms in single crystals can give information about the electronic structures of these atoms in the particular crystal. For example, in single crystals of V,O, the splittings of the 3p and 4p vanadium electronic levels have been determined as 1.0 and 0.8 eV, respectively, and that of the 2 p oxygen level as 1.4 eV.236 Halides nnd Oxyhalides. Molecules of VCI,, prepared by Knudsen cell techniques, have been isolated in solid inert-gas matrices and their ix. spectra indicate a linear structure. However, similar studies suggested that VF, molecules are non-linear.15 The d-d spectrum of gaseous VC1, has been discussed in terms of ligand field theory, and the Tanabe-Sugano matrix for a linear ( D E h )d 3 system pre~ented.~ The Raman spectrum of VCl, has been reported and values for the force constants and various thermodynamic parameters of the molecules have been calculated.238VCl, has been used to investigate the structure of oxide surfaces. The number of OH groups per unit area follows from the amount of HCl liberated, and the arrangement of such groups can then be determined by e.s.r. spect r o ~ c o p y39. ~ Molecular beam-mass spectrometric studies have shown that VF, is monomeric in the vapour phase,240 and mass spectrometric studies of the vapour from solid VOF, ( - 23--30 "C) have shown that it consists of < 10 % dirner~.,~' The formation of VC1, by the reaction of PCl, and VOCl, has been further challenged242on the basis of X-ray and analytical studies, the results of which are consistent with the formation of [PCl,][VCl,] (see Vol.1, p. 36). The microwave spectrum of VOCl, has given values for the structural parameters = 111.8".243 The of V-0 = 159.5, V-Cl = 213.1 pm and L Cl-V-Cl standard heat of formation of VOCl, (1) has been calculated as -710 kJ mol- 1.244 Metathetical exchange of BBr, with VOCl, affords VOBr,."

Sulphides and Selenides. The new compounds V7S8 and V7Se, have been prepared and shown to have NiAs-type structures with ordered vacancies.24 Finely powdered V20,, or NH,VO,, when heated in a stream of H,Se at 900-1300 "C, gives VSe, (n = 1.6--l.75).246 Nitrides and Phosphides. The reaction of vanadium oxides with liquid lithium containing dissolved nitrogen provides a method for the preparation of vanadium nitrides. The oxides V,O,, VO,, V 2 0 3 , and VO are reduced by liquid lithium to the metal. Reaction with nitrogen then occurs forming the a-phase I. B. Borovskii, V. I. Matiskin, and V. I . Nefedov, J. Phys. (Paris). Colloq., 1971. 207. D. W. Smith, Znorg. Chim. Acta, 1971, 5, 231. 238 R. J. H. Clark, B. K. Hunter, and P. D. Mitchell, J.C.S. Faraday ZZ, 1972,68,476. 2 3 9 J. C. W. Chien, J. Amer. Chem. Soc.. 1971,93,4675. 240 M. J. Vasile, G. R. Jones, and W. E. Falconer, Chem. Comm., 1971, 1355. 2 4 1 A. J. Edwards and D. R. Lloyd,J.C.S.Chem. Comm., 1972,719. 242 H. E. Blayden, Znorg. Nuclear Chem. Letters, 1971,7, 1147. 2 4 3 K. Karakida. K. Kuchitsu, and C. Matsumura, Chem. Letters. 1972. 293. 244 V. I. Sonin, N. I. Vorob'ev, Yu. A. Raikov, and 0. G. Polyachenok, Vestnik Akad. Nauk Belarus. S.S.R., Ser. khim. Nauk, 1971, 88. 245 S. Brunnie, M. Chevreton, and J. M.Kauffmann, Materials Res. Bull., 1972,7,253. 246 V. A. Obolonchik and L. M. Prokoshina, Zhur. priklad. Khim. (Leningrad), 1971. 44, 21 66. 236 237

Znorganic Chemistry of the Transition Elements

38

solid solution of nitrogen in vanadium, V,N, VN, or Li,VN,, depending on the concentration of dissolved The crystal structure of V,P has been refined.248 Silicides and Germanides. V,Si, has been prepared by radiofrequency heating

of the stoicheiometric elemental mixture, and characterized by X-ray diffraction studies.29 V,Ge has been shown to have a cubic lattice of the Cr,Si type.24' Hvdrides. Replacement of hydro9en by deuterium or tritium in VH, or (V, Nb)H, results in a more stable compound, the inverse of the normal effect of isotopic s u b ~ t i t u t i o n . ~ ~ ' Vanadium(ri) Complexes.-Dehydration of V S 0 4 , 7 H 2 0 has been shown to proceed via the formation of V S 0 4 , n H 2 0 (where n = 6, 4,or 1) and V(0H)(SO,), which were characterized by X-ray studies.25' The polarographic behaviour and the oxidation potential of the V"-l,2-cyclohexanediaminetetra-acetic acid complex, at pH 6-12, have been determined.252Formation constants and electronic spectra have been reported for the [V(phen),12+ and [V,0(phen)l2' complexes.253The absorption spectrum of Vil ions doped in cadmium telluride has been presented and interpreted on a crystal-field The unpaired spin density in fluorine 2p~-orbitalsof [VF,]'-, arising from covalent transfer and overlap with vanadium orbitals, has been determined by ENDOR spectroscopy and interpreted using a covalent model.25 4 The first study of ring-exchange reactions involving metallocenes has shown that vanadocene is quite inert to exchange with both Li(C,D,) and Ni(n-

c

5 D5)2. 2 5

Vanadium(I1r) Complexes.-0-Donor Ligands. VO(0H) has been prepared by hydrothermal synthesis from V,O, and VH1.3in the appropriate molar ratio, and characterized by X-ray methods.256Similarly, M ' V 0 3 (M' = La, Sm, Gd, or Er)257and M2VW208(M2 = Li or Na) and LnVWO, (Ln = Y, Pr-Er,' or Yb),258obtained by the reaction of the corresponding oxides at elevated temperatures, have been identified. The atomic co-ordinates of UV20, have been redetermined: the vanadium atoms were shown to be surrounded by six oxygen atoms with average V-0 = 196(4) pm.2s9 Magnetic and neutron

247

248 249

250

"'

252 253 254

255

lS6 257 258

259

C. C. Addison. M G. Barker. and J. Benthan. J . C . S . Dalton. 1972. 1035. H. Jawad. T. Lundstrom. and S . Rundqvist. Physicu Scripts, 1971, 3, 43. M. K. Borzhitskaya, V . L. Zagryazhskii, V . I. Surikov, and A. K. Shtol'ts, Trudy Urul. Politekh. Inst., 1970, No. 186207, (From Ref. Zhur. Met. 1971, Abs. N o . 5141). R. H . Wiswall, jun. and J. J. Reilly, Inorg. Chem., 1972, 11, 1691. J. Tudo and G . Laplace, Compt. rend., 1972, 274, C , 1382. T. Kimura, K. Morinaga, and K. Nakano, Nippon Kuguku Zusshi, 1971,92,880. N . L. Babenko and A. I. Busev, Zhur. neorg. Khim., 1972, 17,402. J. J. Davies, S. R. P. Smith, J. Owen, and B. F. Hann, J . Phys. (C),1972,5,245. M. E. Switzer and M. F. Rettig, J.C.S. Chem. Comm., 1972,687. E. Schwarzmann and R. Birkenberg, Z . Nuturforsch., 1972, n b , 76. H. Brusset, R. Mahe, and A. Delroichet, Compt. rend., 1972,274, C, 1293. R. Salmon and G. Le Flem, Compt. rend., 1972,274, C , 292. L. M. Kovba, Radiokhimiyu, 1971, 13, 909.


39

diffraction measurements have been reported for the normal spinel ZnV, 0, ; a value of peff of 2.18 BM was obtained.260 The structures of the anhydrous vanadium(ir1) sulphates. V,(SO,),, yellow (monoclinic) and green (rhombohedral), have been investigated,261and a new double sulphate, (NH,),V(SO,),, has been prepared and extensively characterized.262 Single-crystal magnetic susceptibility studies (1.5-20 K) of guanidinium vanadium(rrr) sulphate have been reported,263and the zero-field splitting has been estimated as 3.74 cm-'. The proton and deuteron linewidths of [V(acac),] and other paramagnetic trisacetylacetonato-complexes and their deuteriated analogues have been measured. As reported for [Ti(acac),] (p. 6), the significantly better resolution achieved for the deuteron spectra suggests that useful information can be obtained from deuteron n.m.r. studies of paramagnetic complexes.45 Ligandfield absorption and emission spectra and magnetic moments of tris-(00'su1phinato)-complexes of vanadium(rrI), [V(RSO,),] (R = Me or Ph with 11 = 2.35 and 2.63 BM, respectively) have been reported.264 [V(H,PO,),] has been prepared by the reaction of VSi, with H3P0,.41 The reaction of VCl, with tetraethyl methylenediphosphonate at temperatures above 120°C has been shown by analytical and i.r. studies to produce the compound VL(LH) (where L = CH,[O(O)P(OEt),],). The electronic spectrum of this = 671, 423, and 353 nm) is consistent with octahedral vancomplex (A,, a d i u m ( ~ ~and ~ ) ,the room-temperature magnetic moment of 2.38 BM suggests that the compound is polymeric rVOL(LH)1,.265A polynuclear cross-linked structure has also been suggested for the related tris(diethylthiophosphat0)vanadium (111) complex, prepared in a similar manner by suspending VCI, in excess triethyl thiophosphate and heating to 15O-2OO 0C.266 The kinetics of the reaction between [V(salen)] in pyridine and oxygen have been determined and interpreted in terms ofthe formation of a [V(salen)]+oxygen adduct. This reinforces the view that vanadium(~11) complexes can act as oxygen carriers.220The oxidation of the 1,2-cyclohexanediaminetetra-acetic acid complex of V"' has been studied in solutions of pH 6-12.252 The nature of the reaction products obtained on refluxing vanadium(rr1) halides with acetic or propionic acids has been confirmed as H[V30(RC0,),]. [VCl(MeC02),I was isolated after reaction under mild conditions. The roomtemperature magnetic moments of the trinuclear species of ca. 2.65 BM are +

260

261 262

263

264

265

266

A. Bombik, B. Lesniewska, and Z. Tucharz, Znst. Tech. Jad., AGH, Rep. 1971, 1TJ No. 9/PS. R.Perret, A. Thrierr-Sorel, and J. P. Larpin, Bull. Soc. frany. Mintral. Cristdlog., 1972, 94, 558. J. Tudo and G. Laplace, Bull. SOC.chim. France, 1971, 3922. J. N. McElearney, R. W. Schwarz, S. Merchant, and R. L. Carlin, J . Chem. Phys., 1971, 55, 466. E. Konig, E. Lindner, I. P. Lorenz, G. Ritter, and H. Gausmann, J . Znorg. Nuclear Chem., 1971, 33.3305. C. M. Mikulski, N. M. Karayannis, L. L. Pytlewski, and R. 0. Hutchins, Inorg. Nuclear Chem. Letters, 1972, 8, 225. C . M. Mikulski, N. M. Karayannis, and L. L. Pytlewski, Inorg. Nuclear Chem. Letters, 1971, 7.785.

40


normal for magnetically dilute V”’, and the electronic spectra are consistent with octahedral co-ordination of this ion.’67 S-Donor Lignnds. LiVS, has been shown to have a crystal structure like that of NiAs. with ordering of Li’ and V”’ in alternate layers.268The deep-brown to orange-red compounds [V(S,PX,),] (X = Me, Ph, OEt, F, or CF,) have been obtained by salt-elimination reactions from VCl, and NaS,PX,. All these compounds are air-sensitive, although the stability of the complexes towards air oxidation varies with X. Their solution electronic spectra suggest that these complexes inyolve a trigonally distorted octahedral VS, chromophore. and BM.’69 Tris(P-thiotheir magnetic moments lie in the range 2.79-2.90 4ketonato)vanadium(m) complexes with 4-mercaptopent-3-en-2-onato-, phenyl-4-mercapto-3-en-2-onato-, and 5-methyl-4-mercaptohex-3-en-2onato-ligands. have been prepared and characterized. These complexes appear to involve the f u c ( O 0 0 : S S S ) isomer exclusively.270 N-Donor Ligands. The full account of the preparation and properties of V[N(SiMe,),], has been p ~ b l i s h e d . ,(Et4N),[V(NCSe)6] ~ has been prepared and its electronic spectrum reported in several solvents.’ 7 1 The electronic spectra of rVL,l(NCS), complexes (L = py, 3-picoline, 3,4-lutidine, or 33lutidine) are consistent with tetrahedral microsymmetry about the V”‘ atom,, 7 2 and the magnetic properties of V”’ complexes with the thiosemicarbazones of salicylaldehyde and pyruvic acid have been interpreted in terms of a tetragonal environment about the metal.’’, Halogen-donor Ligands. The r- and P-modifications of LiVF6 have been obtained by reaction of LiF and VF, (3: I) and quenching or slowly cooling the products. r e ~ p e c t i v e l y .Hyperfine ~~ and superhyperfine interactions of V”’ ions in MF, crystals ( M = Ca, Sr, or Cd) have been studied at 4.2 K . 3 4 The compounds M,[VOCl,] (M = K, Rb, or Cs) are formed when a mixture of M3[VCI,] and Sb,O, (3: 1) is heated. VCl, reacts with Sb’O, at 245-315°C to give VOCl which has different properties from those of VOCl obtained by other r n e t h ~ d s . ’ ~ ~ Organornetallic Complexes. The compounds [ (I~-C~)V(RCO,),] (R = Me, Bz or CF,) involve dimeric molecules, and magnetic studies have indicated that strong metal-metal interactions exist within these d i m e r ~ . ~ ’

Vanadium(1v) Complexes.-Aqueous electron-transfer reactions involving V” as a reductant have been reviewed.275 267 268

269 270 27‘ 2’2

2’3

274

275

B . G. Bennett and D. Nicholl, J. Inorg. Nuclear Chem., 1972, 34, 673. B. Van Laar and D . J. W. Ijdo, J. Solid State Chem.. 1971,3, 590 R. G. Cavell, E. D. Day, W. Byers, and P. M. Watkins, Inorg. Chem., 1971, 10,2716. J. G. Gordon, M . J . O’Connor, and R. H. Holm, Inorg. Chim. Acta. 1971,5, 381. F. Pruchnik, S. Wajda, and E. Kwaskowska-Chec, Roczniki Chem., 1971,45, 537. E. KiSnig and G . Thomas, J . Inorg. Nuclear Chem., 1972, 34, 1173. V. V. Zelentsov, N . V. Gerbeleu, E. V. Ivanov, G. M. Klesova, and A. V. Ablov, Zhur. neorg. Khim., 1972, 17, 874. A. I. Morozov and E. V. Karlova, Zhur. neorg. Khim., 1972, 17, 669. D . R . Rosseinsky, Chem. Rev., 1972, 72, 215.


41

0-Donor Complexes. The preparation and properties of the perovskite metavanadates CaVO, and SrVO, have been reported. Both compounds are metallic conductors and exhibit Pauli paramagnetism. BaVO, has been prepared by sintering Ba4V,09 and V 2 0 3 and shown to have a structure derived from the Ba3V,0s-type. The compound exhibits Curie-Weiss magnetic behaviour above 77K.276 Sc,VO, has been identified in the Sc,O,-V,O, system and shown to have a structure similar to that of fluorite, with oxygen vacancies.277 The structure of UVO, has been determined; the vanadium atoms are co-ordinated to six oxygen atoms, with the V-0 distances in the range 171-242 pm.259 n.m.r. spectra have been reported for oxoWide-line 1 7 0 and vanadium(1v) species in hydrochloric acid solutions over a large range of concentrations and temperatures. The line-broadening observed was attributed to equilibria among the paramagnetic [VO(H,O),]”, [VO(H,O),Cl]’, and [VO(H,O),Cl,] complexes, each of which probably involves an additional water molecule weakly co-ordinated trans to the 0x0 atom.278The formation of V’”-hydroxy-complexes, [VO(OH),]z -‘ has been investigated and their stability and hydrolysis constants have been determined.279The solubility and product of V(OH), at 20°C has been reported as 1.50 2 0.02 x the dehydration of V(OH),,2H20 uia VO(OH), to V,O,(OH), has been observed.2 The vanadyl ammonium double sulphate VOS04,(NH,),S0,,3H20 has been prepared and its dehydration studied.281A 1 : 1 vanadyl-pyrophosphate complex has been shown to be trinuclear as Na,[VOP,0,]3,12H,0 by molecular weight, e.s.r., and magnetic studies.282Crystals of (parH),[VO(C,O,),],2H,O [par = 4-(2-pyridylazo)resorcinol] have been obtained on dropwise addition of an aqueous solution of Na(par) to oxalic acid solutions of vanadium. The i.r. and electronic spectra, magnetic susceptibility, and other physical properties of this compound were reported.283 A series of oxovanadium(rv) carboxylates VO(RCO,), (RCO, = acetate, propionate, butyrate, isobutyrate, valerate, pivalate, phenylacetate, benzoate, or m-chlorobenzoate) have been prepared by the reaction of freshly prepared hydrated V 2 0 4 with a mixture of the corresponding acid and anhydride in toluene or DMF solution, and/or by the reaction of VOCl, and the corresponding carboxylic acid in aqueous solution. I.r., electronic, and e.s.r. spectra 276

’” 270 279

280 281

282 283

Solid State Chem., 1971, 3, 243; (b) A. Feltz and S. Schmalfuss, Krist. Tech., 1971, 6, 367. Yu. Ya. Mikhailov, B. I . Poknovskii, and L. N. Komissarova, Doklady Akad. Nauk S . S . S . R . , 197 1,198,344. A. H. Zeltmann and L. 0. Morgan, Znorg. Chem., 1971,10,2739. I. V. Mel’chakova, D. G. Khadzhidemetriu, N. A. Krasyanskaya, and V. M. Peshkova, Zhur. neorg. Khim., 1971, 16, 1981. A. M. Golub, A. F. Tishenko, A. M. Kalinichenko, and 1. S. Kononenko, Ukrain. khim. Zhur., 1972, 38, 115. J. Tudo, M . Tudo, and G. Laplace, Rev, Chim. mintrale, 1971.8, 841. A. Hasegawa, J . Chem. Phys., 1971, 55, 3101. M. Siroki and C. Djordjevic, J . Less-Common Metals, 1971, 25,431. (a)P. S. Danielson, J .

42


and magnetic properties of the compounds were determined. The magnetic properties ( p = 0.3-0.4 BM) have been interpreted in terms of antiferromagnetic exchange along infinite linear chains of V=O- - -V=O- - - units, linked by bridging carboxylato-groups. This proposed interaction is supported by the low v(V=O) stretching frequency of 890-900 cm-' in these comp o u n d ~ . ~ VO(OH)2, ~ ' . ~ ~ ~prepared by adding ammonia to a solution of [VO(H20)S]S0, in aqueous acetone, affords the green [VO(malonate)] or blue [VO(maleate)] complex when dissolved in malonic or maleic acid, respectively. Addition of a solution of o-phenanthroline or 2,2'-bipyridyl (L) in ethanol to these solutions produces [VO(malonate)L],nH,O and [VOmay be prepared simi(maleate)L],nH,O; [VO(maleate)(Ph,A~0)~],2H,O larly. Various physical properties of these mixed complexes have been determined,285 and their electronic spectra indicate a pseudo-octahedral environment for V". Hydroxyhexafluoroisobutyrate resembles oxalate in its has been isolated co-ordination of metals (34); K2[VO{ OC(CF,),),],H,O and characterized ( p = 1.73 BM).286

The stepwise stability constants for VIV complexes with glutamic, aspartic, A"'-et hylenediaminedisuccinic, and NN'-ethylenediamine-bis-(a-glu taric acid) have been reported.287The 1: 1 oxovanadium(1v) complex of 5-nitrosalicylic = 710 nm), and the mixed species formed acid has been characterized288 between vanadium(rv) with protocatechuic acid (H,L') or gallic acid (H,L2) and 4-aminoantipyrine (aant) have been identified spectroscopically as the 1: 1 : 1 and 1 :2:2 VIV: HL'(HL2): aant complexes.289 The species present in solutions of V 0 2 + and tartaric acid below pH 2 have been identified as [VO(H,tart)] and [VO(H2tart),12- (H,tart = tartaric acid), with formation The e.s.r. spectra of aqueous dinuclear constants of 12.5 and 2.0, re~pectively.~~' oxovanadium(1v) tartrates have been studied at various pH values by freezing in aqueous ethylene glycol at 77 K. The V * V distances were estimated as 420, 520, and 650 pm in the solutions of pH 9,4.8, and 2.8, respectively. The increased separation was attributed to the acidification of the carboxylatogroup, resulting in dissociation of the co-ordinate bond and a change in the 284

A. T. Casey, B. S. Morris, E. Sinn, and J. R. Thackeray, Austral. J . Chem., I972,25,1195.

285

J. Sala-Pala and J. E. Guerchais, Bull. Soc. chim. France, 1971,2444. J. T. Price, A. J. Tomlinson, and C. J. Willis, Canod. J . Chem., 1972,50, 939. M.K.Singh and M. N. Srivastava, J . Znorg. Nuclear Chem., 1972,34, 2081; S. G.Tak, 0. P. Sunar, and C. P. Trivedi, J. Indian Chem. Soc., 1972,49, 121.

286

287

289 290

P. V. Khadikar, Sci. Cult., 1971,37, 444. S. Ya. Schnaiderman, G. N. Prokofeva, and V. G. Zaletov, Zhur. neorg. Khim., 1972,17, 996. R. D.Pizer, Dim. A h . [ B ) , 1970,31, 1138.


43

conformation of the tartrate.291Dimeric species have also been identified for the oxovanadium (rv) complexes of 1-hydroxycyclohexanecarboxylic acid and mandelic acid in DMF solutions and the V O . - - . V O separation has been estimated as 360 pm.292 (R = H, 3-Me, 4-Me, or 3-Me0) The compounds ( a ) Tl,[V(RC,H,O,),] and (b)T12[VO(RC,H,02)2] (R = CHO) have been prepared by the reaction of VO(SO,), TlOAc, and substituted 1,2-dihydroxybenzenes, RC,H3(0H),, in aqueous solution. Their i.r. spectra indicate that in both types of complex all ligand molecules are co-ordinated: thus an earlier formulation of the ( a ) compounds as ( b ) complexes plus a ligand of crystallization is incorrect. The magnetic moments of these compounds, p = 1.7-1.8 BM, are consistent with monomeric species of V" and the electronic spectra of (a) involve chargetransfer transitions extending throughout the visible region. whereas (b)gives d d transitions at 746, 625, and 500 nm, characteristic of o x o v a n a d i ~ m ( v ) . ~ ~ ~ In SO--100% sulphuric acid kanadium(1v) forms a green 1: 1 and a blue 1:2 complex with guaiacol ( o - h y d r o x y a n i ~ o l e ) 1. ~:1, ~ ~1:2, and 1:3 VIV-pyrocatechol complexes have been characterized by their e.s.r., electronic, and i.r. spectra. The yellow 1:1 complex formed at pH 6 has Amax = 380 nm; the blue 1:2 = 590 nm, forms in more acidic media, and the yellow-green 1:3 complex, A,, = 670 nm, is obtained in 95% sulphuric acid.295Equilibrium complex, A,, constants for the oxovanadium( iv) complexes of pyrocatechol, tiron, pyrocatechol-5-sulphonate, pyrogallol, and salicylic and sulphosalicylic acids have been determined.296Two complexes of vanadium(1v) with xylenol orange of (H,R-), [VOH,R]'- and [VOH,R2I3-, have been characterized with A,, 564 (c = 35 700) and 520 nm ( E = 23 600), respectively.297 A new class of crystalline vanadium(1v) compounds, salts which contain the golden-yellow [V(OR)C1,]2- ion, have been prepared by addition of one mole of R'OH (R' = Me, Et, Pr, or Bu) to a slurry of (NR;) or (pyH+)[VCl,] in MeCN-Et,O. Similar attempts to prepare [V(OR),Cl,] -, however, were unsuccessful. Magnetic moments and e.s.r., electronic, and i.r. spectra of these pentachloroalkoxovanadates are consistent with their proposed formulation.,' VOX, (X = C1, Br, or I) react with (Pr'O),MePO to form [VO(O(O)PMe(0Pri)},], which appears to be polymeric.29s The low steric interactions of combined with the weak pyridine 1-oxide and 4-methylpyridine 1-oxide (L1), nucleophilicity of the tetrafluoroborate anion, allow the formation of the

,

291 292

293 294 295

296 29' 298

A. Hasegawa, Y. Yamada, and M . Miura, Bull. Chem. SOC.Japan, l971,44, 3335. T. D. Smith, T. Lund, J. R. Pilbrow, and J. H. Price, J . Chem. SOC.( A ) , 1971,2936. R. P. Henry, P. C. H. Mitchell, and J. E.Prue, J . Chem. SOC.( A ) , 1971, 3392. S. Ya. Schnaiderman and A. M. Pleskonos, Zhur. obshchei. Khim., 1971,41,967. S. Ya. Schnaiderman, A. N. Dermidovskaya, and V. G. Zaletov, Zhur. neorg. Khim., 1972, 17, 665; S. Ya. Schnaiderman and A. M. Pleskonos, Ukrain. khim. Zhur., 1971,37,311. J. Zelinka and M. Bartusek, CON.Czech. Chem. Comm., 1971, 36, 2628. I. N. Chistyachenko, Vestnik Akad. Nauk Kaz. S.S.R.. 1971, 27, 49. N. M. Karayannis, C. M. Mikulski, L. L. Pytlewski, and M. M . Labes, Z . anorg. Chem., 1971, 384,267.


44

[VOL[(BF,),] and [VOL:(BF,),(H,O)] compounds. In contrast, the high steric interactions of 2-methylpyridine 1-oxide (L'). combined with the strong nucleophilicity of the sulphate anion, result in [VOL;(SO,)(H,O)] being obtained.299 Vanadium metal reacts with bromine in DMF solution to give [V(DMF),(Br,),] which is slowly oxidized to afford the [V0(DMF),l2' complex. The complexes [VO(C,O,)L,] (L = DMF, formamide, urea, or ethyleneurea; L, = en) have been prepared by the addition of an acetone solution of the ligand to an aqueous acetone solution of VO(C,O,). A square-pyramidal structure with a bidentate oxalato-group and unidentate L ligands has been suggested for these complexes.300 Treatment of VO(C,O,) or VOBr, in acetone with a 504 excess of diphenyl sulphoxide (DPSO), produces [VO(C20,)(DPS0),] or [VOBr,(DPSO),], r e s p e ~ t i v e l y . ~ Dimethoxy~' ethane forms 1 : i and 2 : l adducts with VCI,, both of which appear to be monomeric cis-octahedral c o m p l e x e ~ . ~ ~ . The e.s.r. spectra obtained for several oxovanadium (IV) complexes, including [VO(acac),]. orientated in nematic glasses, compare favourably with those obtained by dilute single-crystal procedures.302 X-Band e.s.r. spectra of magnetically dilute glasses at 77 K show that EtOH and py form weak complexes with [VO(P-dik)] molecules [P-dik = acac, bzac, tropolone, 3-bromotropolone, (35), or (36)], and that vanadium(1v) in solutions of these Me

O

8

0

HOH,C

a:

chelates is readily oxidized to vanadium(v).,03 The dipole moments for [VO(acac),] dissolved in benzene and dioxan have been estimated as 3.2, and 3.9, D, respectively. The larger value for dioxan is regarded as definite The i.r. and electronic evidence for 1 : 1 complex formation in this spectra of [VO(P-dik),] complexes [IP-dik = acac, bzac, dibenzoylmethane, dipivaloylmethane, bis(p-methoxybenzoyl)methane,trifluoroacetone, or pivaloyltrifluoroacetone] have been interpreted as indicating strong 0-and ionic metal-ligand bonding, but weak x-metal-ligand bonding, for these distorted square-pyramidal complexes.305 A 1 :2 oxovanadium(1v) complex with 299

300 301

302 303 304

305

M . Pavicic, Proc. N . Dakota Acad. Sci., 1971, 24, 114. D. N . Sathyanarayana and V. V. Savant, Z . anorg. Chem., 1972,387, 373. V. V. Savant and C. C. Patel, J . Inorg. Nuclear Chem., 1972,34, 1462. J. P. Fackler, jun., J. Levy, and J. A. Smith, J . Amer. Chem. SOC.1972,94,2436. C. P. Stewart and A. L. Porte, J.C.S. Dalton, 1972, 1661. M . J. Aroney, H . Chio, J. M . James, R.J. W. Le Fevre, R. K . Pierens, and K. R. Skamp, J.C.S. Dalton, 1972,712. J. M . Haigh and D. A. Thornton. H e h . Chirii. Acta, 1971. 54, 2221.


45

1-hydroxy-9,lO-anthraquinone has been synthesized and characterized by i.r. spectroscopy.306 Complexes with Oxygen and Other Donor Atoms. The crystal structure of the 4-phenylpyridine adduct of [VO(acac),] has shown that the molecule adopts an approximately cis-octahedral structure (37) with a V=O bond length of 158(1)pm.307 0

II ,07

Ph

I I

OH

(37)

(38)

Nitriloacetic acid reacts with vanadium-(111).,-(rv), or -(v) oxides to form oxovanadatranetrionic acid (38).308The crystal structure of [VO(C,,H,NO),] (C,,H8NOH = 2-methyl-8-quinolinol) has shown that the vanadium atom has a five-co-ordinate trigonal-bipyramidal environment, with three oxygen atoms in the equatorial plane and the two nitrogen atoms of the bidentate ligand in the apical positions.309 The optimum conditions for the formation of a 1 :2 :2 vanadium(w)-morin4aminoantipyrine system have been described as: pH 5, a tenfold excess of morin (39), and a 3300-fold excess of 4-aminoa n t i ~ y r i n e .O~ ' OH

0

'OH (3 9)

Absorption and c.d. spectra of the complex formed between oxovanadiumand the Schiff base derived from (R)-1,2-propanediamine and two moles of acac indicate that the co-ordinated Schiff base moiety is close to planarity.311 The lack of spin-spin coupling between metal centres in "'-propylenebis(salicyliminato)oxovanadium(Iv) molecules ( p = 1.78 BM) has been di~cussed.~Some seven new oxovanadium(1v) complexes with N-(2-hydroxy(IV)

306 307

308

309 310 3" 312

R. A. Walker, Spectrochim. Actu, 1971, 27A, 1785. M. R. Caira, J. M. Haigh, and L. R. Nassimbeni, Inorx. Nuclear Chem. Letters, 1972, 8, 109. M. G. Voronkov and S. V. Mikhailova, Khiin. yeterotsikl. Soedinenii. 1971, 7 , 1606 M. Shiro and Q. Fernando, Anal-vt. Chem., 1971,43, 1222. S. Ya. Schnaiderman and G. N. Prokofeva, Zhur. neorg. Khiin., 1971, 16, 2222. H. P. Jensen and E. Larsen, Acta Chem. Scund., 1971,25,1439. D. M . L. Goodgame, and S. V. Waggett, Inorg. Chiin. Acta, 1971,5, 155.

46


phenyl)-2-hydroxynaphthylidenimines have been prepared by the reaction of VOCI, with 15 less than the stoicheiometric quantity of ligand in EtOH. ( p = 1.47 BM)and naphth-5Thecomplexes with naphth-4-phenylaminophenol nitroaminophenol ( p = 1.44 BM) appear to involve antiferromagnetic coupling.31 Five-co-ordinate compounds VOL (H2L = dibasic Schiff base derived from 1,3-diaminopropan-2-01 and salicylaldehyde, 3-aldehydosalicylic acid, 5-chlorosalicylaldehyde. or acac, or 1,3-diaminopropane and salicylaldehyde) have been prepared and characterized by analytical, spectroscopic, and magnetic The complexes [VO(o-(RN :CH)XC,H,O},] (X = H, R = Ph, MeC6H4, 2,6-Me2C,H,, or 2,6-Et2C,H,) and [VO(l(RN=CH)-2-(HO)C1 *H6),] appear to have a square-pyramidal co-ordination geometry: however. when X = C1 or Br distortion of this _geometry is apparent. The complexes form 1 : 1 adducts with ~ y r i d i n e . ~ ' ~ The new series of oxovanadium(1v) complexes with Schiff bases derived from 2-aminothiophenol and substituted salicylaldehyde (40)or 2-hydroxynaphthaldehyde has been synthesized and characterized. The ligands (40a),

(40) R' = H, C1, Br, or NO, R2 = H or C1 R3 = H or C1

which can co-ordinate as bivalent 0, N, and S , terdentate ligands, cyclize if heated to form the corresponding (40b) derivatives. which act as univalent 0 and N bidentate ligands. The complexes [VO(OZVS)],nH,O (n = 0 or 1) exhibit subnormal room-temperature magnetic moments ( p = 1.27-1.28 BM), the temperature variation of which supports antiferromagnetic exchange. [V0(2-hydroxynaphthaldehyde-2-aminothiophenol)~.H2O has j/ = 1.52 BM, and the [VO(O;Y),] complexes have p values in the range 1.69-1.86 BM.316 The oxovanadium(1v) complexes, [VOL,], of the monothio-P-diketones C,H,SC(SH)==CHC(O)CCF, and p-O2NC6H4C(SH)=CHC(O)OC2H, (HL) appear to involve V=O - - - - V=O - - - - interactions in the solid state, judging by their golden-yellow colour which contrasts with the green of other monothio-P-diketonato-complexes of oxovanadium(1v); this is supported by a low v(V=O) stretching frequency of cu. 870 cm- '. Surprisingly, the room-tempera3'4 315 316

G. 0. Carlisle and D. A. Crutchfield, Inorg. Nuclear Chem. Letters. 1972, 8, 443. K. Dey and K. K. Chatterjee, Z . anorg. Chem.. 1971,383, 199. Y. Kuge and S. Yamada, Bull. Chem. SOC.Japan, 1972, 45, 799. C. C. Lee, A. Syamal, and L. J. Theriot, Inorg. Chern., 1971, 10. 1669.


47

ture magnetic moments are 1.78 and 1.74 BM. Pyridine appears to break down the polymeric structure, and forms adducts with v(V=O) of ca. 965 cm-'. Molecular weight studies indicate that, even in non-co-ordinating solvents, the V=O----V=O---- bridging is disrupted with the formation of predominantly monomeric units., l 7

S- and Se-Donor Ligands. The te trakis(dithiocarboxylato)vanadium(rv) complexes [V(RCS,),] (R = Me, Ph, Bz, or p-tolyl) have been prepared by dissolving VOCl, or VCl, in absolute ethanol (0.03 mol 1 - I ) and adding an equal volume of a solution of RCS, (0.3 mol 1 - I ) in ether. The magnetic, e.s.r., and i.r. properties of these complexes are consistent with the presence of eight-co-ordinate VS, trigonal-dodecahedra1 chromophores? l8 This inference has been confirmed for [V(BZCS,),]~~'and [V(MeCS,),].218 For the latter, the crystal structure consists of two types of molecule, one where the ligands chelate over the four rn-edges of the dodecahedron. and the other where two ligands chelate over rn-edges and two over g-edges; this is apparently the first example of this arrangement. VOSO, reacts with morpholine-4-carbodithioate [mdtc (4)](1:2) in aqueous solution, pH 4,to form a dull-brown compound which is unstable and slowly

, S-

/CH2--CH2\ 0

'CH,-CH~

/

N-C

*s

changes to form dull-green [VO(mdtc),]. The electronic spectrum of this complex consists of absorption maxima at 610, 550, 435,and 290 nm, which suggests a square-pyramidal VOS, c h r ~ m o p h o r e . ~Although ~' the e.s.r. spectrum of [VO(S,P(OEt),},] had been reported previously, the first isolation and characterization of [VO(S,PX,),] complexes (X = Me, Ph, CF,, OEt, or F) has been reported. The electronic and e.s.r. spectra of these compounds were obtained and their magnetic properties investigated. Complexes with X = F or CF, exhibit anomalous magnetic behaviour which is believed to arise because of molecular associations along V=O - - - - V=O - - - chains., Salts containing the anions of thio- and seleno-phosphinic acids [R,P(X)Y]- (L) (R = Et or Pr; X, Y = S , Se) react with VCl, and VOSO, to give VL, and VOL,, respectively. The 1 : 1 pyridine adduct of [VO(S,PEt,),] was also prepared in this J. B. McCormick and R. A. Bozis, Znorg. Chem., 1971,10,2806. 0. Piovesana and G. Cappuccilli, Znorg. Chem., 1972,11, 1543. 3 1 9 M. Bonamico, G . Dessy, V. Fares, and L. Scaramuzza, Cryst. Struct. Comm., 1972, 1, 91. 320 D. H. Brown, G. Aravamudan, and D. Venkappayya, J . Chem. Soc. ( A ) , 1971, 2744. 3 2 1 R. G. Cavell, E. D . Day, W. Byers, andP. M. Watkins, Znorg. Chem., 1972,11, 1591. 322 H . Hertel and W. Kuchen, Chem. Ber., 1971, 104, 1740. 317

3L8

48


N-Donor Ligands. E.s.r. spectra of the [V(NEt,),]-EtAlCl, system, in heptane solution, have shown that the olefin polymerization catalysts are the 1: 1 or 1: 2 adducts. which are formed for V: A1 ratios of grcater or less, respectively, than 4:l.323 VOC1, reacts with ammonia at room temperature to give [VO(NH,),]Cl,. which appears to involve weak V=O- - - -V=O - - - - interactions since ki = 1.62 BM and v(V=O) = 985 cm-’.324 [VO(NH20H),12’ has been characterized in solutions of pH 6-8.5 following reduction of vanadate by h y d r ~ x y l a m i n e . ~ ~ In the presence of 8-hydroxyquinoline (HL) or o-phenanthroline and thiocyanate, vanadium(rv) is quantitatively extracted into BuOH as H,L[VOL(NCS),] or [VO(phen)(NCS),],BuOH, r e ~ p e c t i v e l y . ~ ‘ ~ Good evidence for the formation of dimeric 4,4’,4”,4’”-tetrasulphophthalocyanine oxovanadium(rv) species in H,O-DMF solution5 has been obtained from e.s.r. spectra, and the metal centres are estimated to be 450 pm apart. In aqueous solution, although dimers are present, most of the oxovanadium(1v) complexes are polymerized, and in DMF solution substantial amounts of monomer exist.32- Stability constants for the formation of 1 : 1 complexes between pyridine and some oxovanadium(iv)-2,4-disubstituted deuterioporphyrin dimethyl esters have been determined in chloroform solution at 25 “C. Magnetic and spectroscopic evidence suggest the presence of an electronic interaction between V 0 2 + centres in these compounds.328 Conzplexes with Nitrogen and Other Donor Atoms. The complexes VOR, (where HR = 7-halogeno-substituted 8-mercaptoquinoline) have been prepared for all halogens as substituents and characterized by their electronic spectra.329 The compounds [VOL],nH,O (L = dinegative anion of thiosemicarbazones of salicylaldehyde, 5-chlorosalicylaldehyde, or 5-bromosalicylaldehyde: n = 1.5 or 1)have been prepared. Their low magnetic moments have been taken as indicative of dimeric structures which involve a direct V-V i n t e r a ~ t i o n . ~The ~ ’ pseudo-octahedral complexes [VO(sesp)L,],nH,O and [VO(sesa)L,],nH,O have been characterized (H,sesp and H,sesa are the selenosemicarbazones of pyruvic acid and salicylaldehyde: L = py, in = 2: L = phen, or 2,2’- or 4.4’-bipy,m = 1).The related anion [VO(sesal)]- (H,sesal = 1.4-disalicylidene-3-selenosemicarbazide) appears to have a square-pyramidal

323

’’’ 326

327

328

’’’ 330

C . Busetto and N. Pnll:idino. Chiriticn ( ’ fndtrsrria. 1971. 53.934. L. V. Kobets, N . 1. Vorob’ev. V. V. Pechkovskii, and A. I . Komyak, Zlrirr. priklad. Spectroskopii, 1971, 12, 6 8 2 ; L. V. Kobets, L. P. Dmitrieva, N . 1. Vorob’ev, and V. V. Pechkovskii, Doklady Akad. Nauk Beloruss. S . S . R . . 1971, 15, 713. A. T. Pilipenko, 0.I. Karpova, V. V. Lukachina, andV. V. Trachevskii, Zhur. analit. Khim., 1972, 27,78. V. P. R. Rao, D. Satyanarayana, and Y. Anjaneylu, Proceedings of the Second Chemistry Symposium, 1970. 1. 151. P. D. W. Boyd and T. Smith J.C.S. Dalton, 1972, 839. E. Higginbotham and P. Hambright, Inorg. Nuclear Chem. Letters, 1972,8,747. J. Bankovis, M . Krasovska, L. Cera, J. Lejejs, and R. Lazdina, Latvijas PSR Zinatnu Akad. Vestis., Khim. Ser., 1971, 742. M . D. RevenkoandN. V. Gerbeleu, Zhur. neorg. Khim., 1972,17,1018.


49

structure in which the selenium is not co-ordinated to the oxovanadiurn(IV).~ P-Donor Ligands. E.s.r. have shown that the family of [VOCl,(PR,),] complexes (R = Me, Et, Pr, Bu, or Ph, or R, = Ph,Et) preferentially adopt a trigonal-bipyramidal rather than the square-pyramidal geometry usually typical of oxovanadium(rv) complexes. The adoption of this structure appears to be a consequence of the steric requirements of the phosphine ligands {cf: CVOC1,(Me3N),I 3. Halogen-donor Ligands. Blue prismatic crystals of Cs, [VF,] have been obtained by dissolving V , 0 5 and V 2 0 3 (1 : 1) in 40% hydrofluoric acid and adding Cs,CO,. X-Ray studies have shown that the crystals consist of [VF,]'octahedra.333A calorimetric study of [VOF,,xH,O] (n = 1, 2, 3, or 4) complexes in aqueous NaClO, (l~Omoll-l),has shown that they are entropystabilized and have AG values of - 19.2, - 13.5, -8.9, and -4.5 kJ rnol-', 34 re~pectively.~ [VO(MeCO,),] reacts with PPh, in thionyl chloride to form (ClPPh,),[VCI,], which undergoes reduction when heated to form (CIPPh3)[VC1,].267 N.q.r. spectra have been reported for Cs,[VOCI,],H,O and the covalency in this and other d' systems discussed.335Metallic copper reacts with VOCl to give a product of stoicheiometry CuVOCl,, which may be either a discrete compound or a CuCl + VOCl, mixture. Similarly, CuVCI, is formed when liquid VCl, is distilled on to copper foil in the absence of air.,,,

Organometdic Complexes. Me,VCI, has been prepared by treating VCl, in organic solvents with ZnMe,.,08 The complete account of the preparation and properties of [V(CH,SiMe,),] has been published. This dark-green compound, m.p. 43 "C, exhibits electronic absorption maxima at 640 and 424 nm, together with a weak broad band in the near 1.r. The magnetic moment is 1.55 BM in benzene solution and 1.30 BM in the solid.,,' Tetrabenzylvanadium has been prepared by treating VCl, in pentane with Bz,Mg and Et,O at -20°C. The compound was characterized by i.r. and e.s.r. spectra, and the details of the latter suggest that the molecule has a distorted tetrahedral structure similar to that of the zirconium a n a l ~ g u e . " ~Treatment of VCI, in pentane with 1-norbornyl-lithium affords tetrakis-( 1 -norbornyl)~anadium.~ Dilute single-crystal e.s.r. spectra have been obtained for [(7c-Cp),VC12] in [(n-Cp),TiCI,]. The experimental results were interpreted using MO calculations which indicate that the unpaired electron is in an a,-type M O

336

N. V. Gerbeleu, M. D. Revenko, and A. V. Ablov, Zhur. neorg. Khim.. 1972,17, 136. G. Henrici-Olive and S. Olive, J . Amer. Chem. Soc., 1971, 93, 4154. A. Carpy and K. Waltersson, Compt. rend., 1972,214, C, 405. S . Ahrland and L. Kullberg, Actu Chem. Scund., 1971,25, 3471. R. D. Bereman, Inorg. Chem., 1972, 11, 642. K. Lascelles and R. A. J. Shelton, J . Less-Common Metals, 1972,27,423.

337

W. Mowat, A. Shortland, G. Yagupsky, N. J. Hill, M. Yagupsky, and G. Wilkinson, J . C . S .

331

332 333 334

335

Dalton, 1972, 533.

E


50

composed primarily of the metals' d_, and d,2-y2 orbitals.338 [(n-Cp),VCl,] reacts with NOPF, in MeCN to give the dark-green [(n-Cp),V(MeCN),](PF6),.339A mixture of m- and p-nitrobenzoyl peroxides reacts with vanadocene in THF solution to give the corresponding [(n-Cp),V(0,CC6H,N02)2] benzoate derivative^.'^^ These molecules, and also [(n-Cp)V(PhCO,),], have been shown to have monomeric and i.r. spectra have been reported for [(n-Cp),V(O,CC,H,N02-~)2] and [ ( K - C ~ ) , V ( P ~ C O , ) , ] . ~ ~ ~

Mixed-valence Oxide Compounds involving Vanadium (iv).-The majority of these compounds involve vanadium-(rv) and -(v) in oxide lattices and much of this work is summarized in Table 3. The crystal structure of LiV,O, has been shown to involve distorted square-pyramidal environments about both the vanadium-(Iv) and -(v) ions.'49 Electrolysis of a Cs,O-V20,(46 :56 mol 7;) melt at 585 "C affords single crystals of C s V 2 0 , which, in contrast to the lithium salt, contain vanadium-(rv) and -(v) ions with tetrahedral and trigonal-bipyramidal co-ordination geometries, respectively.340CaV,O, crystals may be prepared by the hydrothermal reaction of Ca(OH), with V 2 0 5 (2: 1) and X-ray studies have shown that they involve distorted square-pyramidal V O units connected by common Partial substitution offluorine for oxygen in VO, and V,O, has been achieved by treating these oxides with aqueous hydrofluoric acid under pressure. The new phases of composition VO,-,F, (for 0 < x < 0.2) and V,O,-,F, (for 0 < .Y < 0.025) were obtained and characterized by X-ray diffraction The oxide-fluoride bronze Ko~2,VOo.,5F,~2, has been prepared from the high-temperature reaction of KVO, and VF, and the unit cell parameters have been determined.343 Table 3 Compounds containing vanadium-(Iv) and -(v) in oxide lattices Cornpoitnd

Source

LiV,O, + V,O, at 650 "C

V,O,-KCl 470-530 'C V,O,-KCI 470 "C 338

339 340 34' 342

343

Properties reported R eJ

X

U

e.s.r. spectra unpaired electrons close to V atoms

b

kinetics of formation

c

D. P. Bakalik and R. G. Hayes, Inorg. Chem., 1972, 11, 1734. N. G. Connelly and J. D. Davies, J. Organometallic Chem.. 1972, 38, 385. W. G. Mumme and J. A. Watts, J. SolidState Chem., 1971,3, 319. A. Kutoglu and S. Schulien, Naturwiss., 1972, 59, 36. M. L. F. Bayard, T. G. Reynolds, M. Vlasse, H. L. McKinzie, R. J. Amott, and A. Wold, J. Solid State Chem., 1971, 3, 484. A. Carpy and J. Galy, Acta Chern. Scand., 1971, 25, 1918.


51


Rb20,5V204 Rb20,4V304 Rb,0,nV,04 (n = 2 or 3) Rb20?V308

I

Source

Properties reported

Re$

Rb,O-V204-VZOs system

X

d

X X

f

RbxVZO 5 (X = 0.30, 0 . 4 M . 4 2 , 0.624.70) Sr6V6019

TI,O-V,O,-VO2 system

T12V308

TlXVZOS x = 0.30-4.36 = 0.44-4.48 =

T1,O-V20,-VO, system

0.22

V9M06040

'ZW07 w07

X, m.p. 600 "C(0.30)g X, m.p. 610 "C (0.45)

X V20,

+ MOO,

m.p. 630 "C

h

structure related to that of TiNb207 i

(w0.2v0.8)307

2'

e

V-W-0 system

X

j

AgzO-V20s (1 :6)

i r . , m.p. 692 "C,X

k

.S

AgV601S

(u) J. Galy, J. Darriet, and P. Hagenmuller, Rev. Chim. minkrule, 1971, 8, 509. ( b ) A. A. Fotiev, E. D. Stoler, R. N. Pletnev, and Yu. N. Belyakov, Trudy Inst. Khim. Akud. Nuuk S.S.S.R., C'rul. Filiul, 1970, 37. (c) A. A. Fotiev and L. L. Surat, ibid., 1970, p. 1 1 . (d)J. Tudo and B. Jolibois, Compt. rend., 1971, 273, C, 1526. (e) Ref. 275 (b). (f) J. Tudo and B. Jolibois, Compt. rend., 1971, 273, C, 466. (g) M. Ganne and M. Tournoux, ibid., p. 975. (h) A, Bielanski, K. Dryek, J. Pozniczek, and E. Wenda, Bull. Acad. polon. Sci., Skr. Sci., chim., 1971, 19, 507. (9 J. Darriet and J. Galy, J . SolidSfafeChem., 1972, 4, 357. (J) S. Launay-Mondet, Rev. Chim. minkrule, 1971, 8, 391. ( k ) B. V. Slobodin, Trudy Inst. Khim. Akad. Nauk S.S.S.R., Ural. Filial, 1970, 121, 24.

Vanadium(v) Complexes.-0-Donor Ligands. A large number of metal vanadates and mixed oxide compounds containing vanadium(v) have been characterized, and the majority of these studies are summarized in Table 4. A determination of the crystal structure of the pseudo-trisodium vanadate, Na3V0,,(NaOH),~,,,,,12H,0, has shown that it should be formulated as 3(0H)o-l(H,0)4,](V0,)4, the average bond length in the vanadate [Na, ion being 161 pm.344 The crystal structure and iron Mossbauer spectrum of FeVO, have been reported and the iron(Ir1) shown to occupy octahedral and trigonal-bipyramidal An X-ray diffraction study of the solid solution , has shown that the average bond length in the [VO4I3Bi, - x , 3 M ~ x V-x04 tetrahedra is 177 pm.346The thermochemical radii of [VO4I3- and [VO,]344

345

346

E. Tillmann and W. H. Baur, Acta Cryst., 1971, B27,2124. B. Robertson and E. Kostiner, J . Solid State Chem., 1972, 4, 29. M. Cesari, G. Perego, A. Zazzetta, G. Manara, and B. Notari, J . Znorg. Nuclear Chem., 1971, 33,3595.


52

have been estimated as 248 and 178 pm, respectively, from the standard heats of formation of their alkali-metal salts, using the Kapustinskii Heats of formation of several other vanadates have also been estimated.73 P-Sr,V,O, is isomorphous with P-Ca,P,O-: the anion therefore has the dichromate-type structure with nearly eclipsed V 0 3 groups. The V-0-V interbond angle is 123', and the bonds involving the bridging oxygens, 181 pm, are longer than those involving the terminal oxygens, 163-177 pm.348 The new compounds MVTeO, (M = Na, K, Rb. or Ag) have been identified

Vanadates and mixed oxide compounds containing vanadium ( v )

Table 4

Properties reported Li2C0, + V,O,: X < 600 :C prolonged heating N a 2 C 0 , + VIO,: X 650 C in a stream of 0, V20,-Na,Si0, system: 298-- 1098 K A H

Compound LiVO,

Source

r-NaVO, NaVO, NaV601

5

Na,V,002Na,VO,

Na20 + V20j: X 350 'C under Ar. 15 h

K 2 0 . V , Oi.2S0, K ,0.V20,,4S0, 6K20.V,0,.12S0,

ME,V,O 1 . 1 MEJP? Mg,V20, CaV&@2 1 SrV,O, Sr2V20Sr,V,O, SrV 206 .4H 2O Sr2V20-.3H20 Sr,V, 0 , . 6 H 0 Sr2V,0,7.14H,0

I

V20j-K2S20system

i.r.

V,O,-MgO

m.p. 760 "C

system'

m.p. 1132°C m.p. 1212°C m.p. 645 "C. t.d.

V,O,-CaO SrO-V,O,

( < 1 : 1)

system

+ Sr(N03)2

K3V04

in aqueous solution

b

c

d

e

.f LJ

ir., m.p. 658 "C i r . , m.p. lOlO*C h i.r., m.p. 1250°C, X i

i,r,. t.d., X

M :V 0 - .sH 0 ( M = Ca, Sr, or Ba, s = 2. 1.5. or 0.5. resp.)

pptn. from Na,V,O, with MIOH), at pH 11 ix., t.d., X

BaV206

V , O j + BaCO,: 700 'C/24 h V 2 0 , Tl,CO,: 250--550 'C. or K,VO, + TlNO,

TlVO, TI,VO, TI,V, 0

Ref II

i

k

X

+

X

34'

A A. Fotiev and B. G . Golovkin, Trudv Inst. Khim. Akad. Nauk S.S.S.R., Ural Filial. 1970,

348

No. 20. 3. J. A. Baglio and J. N. D a n n , J . SolidSiate Chern.. 1972.4. 8 7 .


53

Table &continued Compound

TlVO, TlV,O, T13 v 8 °2 1

T13V50

14

f3-V0PO4

i

ZrV,O, FeVO, FeV,O,

Source

Properties reported

T1,-V,05 system

m.p. 506 "C, X m.p. 518 "C. X

NH4V0, (NH,)3P0, at 595 C ; 1 atm of 0,

X

Ref

m.p. 405 "C, X

X

+

n

metals in a V 2 0 5melt

0

c03v208

Ni3V,04 Fe2V4013

Fe203

+ V205

m.p. 715"C, X

p

( < 1 : 1) 640"C/5 h

Ni(OH)V0,,2.2H20 Ni,(OH),V20,,5H,0 Ag2V40 1 1 a-Zn,(VO,), ZnV,O, ZnV,O, Zn4V209

Hg3V205 Na4HgV208 LaVO,

V,O,-NiO-Na,O-H,O system Ag,O-V,O, system low temp. form.

V,O,-ZnO system

4

i.r., m.p. 532 "C, X X , isostructural with Mg3(VOJz, V-0 = 171 pm

s

X

t

r

NaVO, + HgNO, in U aqueous solution ix., R, st, [VO4I3- u V2OS + La,O,; in air, 110O0C/5h tetrahedral with

v-0

=

168-1 78 pm

st

NdVO, LnVO, 4Ln,O,,VzO5 (Ln = La-Lu except Ce and Pm) 5Ln203,V205 (Ln = Sm-Yb) ~L~,O~,V~OS (Ln = Pr or Nd) LnAV,O, (Ln = La, Dy, Y, Sm, Nd, or Gd; A = Li, Na, or K)

W

Y

A2C03 + Ln,O, + V,O,; 800 "C/10 h 1200-1300 'C/12 h

+

e, X , pyrochlore structure

Y

(a) W. Freundlich, A. Erb, M. Quarton, and J. Perraud, Compt. rend., 1972,274, C , 627. (b)E. Erdos, J . Appl. Crystallog., 1972, 5 , 141. (c) N. Kh. Valikhanova, V. P. Malyshev, and A. A. Fortiev, Vestnik Akad. Nauk K a z . S.S.R., 1971,27,65. ( d )G. Le Flem, R. Olazcuaga, J. P. Parant, J. M. Reau, and C. Fouassier, Compt. rend., 1971,273, C , 1358. (e) Zh. G. Bazarova, G. K. Boreskov, A. A. Ivanov, L. G. Karakchiev, and L. D. Kochkina, Kinetika i Kataliz, 1971, 12,948. cfl E. I. Speranskaya, Zzuest. Akad.

54


N m k S.S.S.R.. Neorg. Muteriuly, 1971. 7, 1804. (9) P. I. Fedorov, N. P. Slotvinskii-Sidak, G . V. Vorob'eva, and V. K. Andreev. I x e s r . V. L'. 2. Khini. i khim. Tekhnol.. 1971. 14. 1750. ( h ) S. Solacolu, R. Dinescu, and M. Zaharescu, Rev. Roumaine Chim., 1972,17,311. (i) Ref. 275(b).(i)A. P. Nakhodnova, L. N. Kovgan, and T. V. Ivanova, Izvest. Akad. Nauk S.S.S.R., Neorg. Materialy, 1972, 8, 523. ( k ) P. Schwendt, P. Petrovic, and L. Zurkova, Coll. Czech. Chem. Comm., 1971,36, 3780. (f) M. Ganne and M. Tournoux, Compt. rend., 1971,273, C, 1858. ( m ) J. Tudo and B. Jolibois, ibid., p. 466; M. Touboul, ibid., 1972,274, C , 861. (n)E. Bordes and P. Courtine, ibid., 1972,274, C, 1375. (0)S. Muroi, M. Someno, and M. Kobayashi, Tetsu To. Hagane, 1972, 58, 773. ( p ) Y. Otsubo and K. Utsumi, Nippon Kagaku Zasshi, 1971,92, 737. (4)V. I. Elfinov, I. Ya. Beznikov, and V. L. Zolatavin, Trudy Inst. Khim. Akad. Nauk S.S.S.R.,C'rul. Filial, 1971, 122, 130, 134. (r) B. V. Slobodin, ibid., 1970, 24. (s) R. Gopal and C. Calvo, Canad. J . Chem., 1971, 49, 3056. ( t ) V. A. Makarov, A. A. Fotiev, and L. N. Serebryakova, Zhur. neorg. Khim., 1971, 16, 2849. ( u ) R. S. Saxena and C . P. Sharma, J . Inst. Chem. Calcutta, 1971, 43, 121. ( L ' ) H. Brusset. F. Madade-Aubry. R. Mahe. and C . Boursier, Compt. rend, 1971, 273, C , 455; E. J. Baran and P. J. Aymonino, Z . anorg. Chem., 1971, 383, 220. (w) J. A. Baglio and 0. J. Sowers, J . Solid State Chem., 1971, 3, 458. (x) H. Brusset, F. Madaule-Aubry, B. Blanck, J. P. Glaziou, and J. P. Laude, Canad. J . Chem., 1971,49, 3700. ( v ) V. S. Chincholkov, J . Inorg. Nuclear Chem., 1972,34, 2973; J.C.S. Chem. Comm., 1972, 723.

in the M,O-V,O,-TeO, system and were shown to be isostructural. A determination of the crystal structure of NaVTeO, showed that it contains VO, tetrahedra incorporated into chains of (VTe0,);- anions.349 Vibrational spectra of some vanadate salts"2".350 and several mineral species containing condensed vanadate ions3 have been reported. Raman spectra have been determined for the garnets NaCa,MtV,O, (M1 = Mg or Zn),'* and-neutron diffraction analyses of the related com( M 2 = Ni or Cu) presented.353 The garnets pounds NaCa,M:V,O,, Na,LnM;V,O,, (Ln = Bi, Y, or Pr-Lu, except P m ; M 3 = Mn, Co, Ni, or Zn), Na3Sc,V3012, NaCa,Mn,V,O,,, and NaCd,Mg,V30,, have been synthesized using conventional ceramic technique^.',^ The results of some studies concerned with the preparation and properties of iso- and hetero-polyanions containing vanadium(v) are summarized in Table 5. Acidification of solutions of [V2W40,,]4- is an efficient means of preparing the red complex V,W,O,,'-, previously formulated as V,W,O, which has been isolated as Na. K, NH,. NMe,, C(NH,),, and C,H,(NH,), salts. [V4W9049]6- is most stable at pH 3. At pH 5 it is converted into [V2W,019]s- and isopolytungstate. The free acid is formed on acidification and may be extracted with ether. 1.r. and chemical evidence, together with comparisons with metatungstate. suggest that the ion has a Keggin structure [V(W9V3)0,0]6-. Several other species are also obtained on acidification of [V,W,0,,]4- : one of these, K,V,W,00,,,20H,0, has been isolated and appears to have the Keggin structure [V(W10V2)040]5-.355 The [V,W,0,0]7+'Iseries, has been isolated ion, the fourth member of the [V(W - nVn)040](3

,-,

,

349

350 351

352 3s3

35s 355

J. Darriet, G. Guillaume, K . A. Wilhelmi, and J. Galy, Acta Chem. Scand., 1972, 26, 59 E. J. Baran and P. J. Aymonino, 2.anorg. Chem., 1971, 383, 226. A. S. Povarennykh and S . V. Gevork'yan, Mineral Sb.(L'cou). 1970.24, 254. W. B. White and G. Vassilis, J . Amer. Ceram. SOC.,1971,54,472B. Yu. V. Lipin and Yu. 2. Nozik, Latvijas PSR Zinatnu Akad. Vestis, Fiz. Teh-.Zinat, Ser., 1971, 122: 123. G. Ronniger and B. V. Mill, Kristallografiya, 1971, 16, 1035. C. M. Flynn, jun.,and M. T. Pope, Inorg. Chem., 1971, 10,2745.


55

Table 5 Iso- and hetero-pol'yanions containing vanadium ( v ) Species

Comments und reported properties Ref: prepared by cation-exchange reactions, * u d, i.r., t.d., soly. prod. of Ba,V,0028,19H20 = 8.54 x (22 "c) X, monoclinic P2/m b stability constant = 6.3 x lo5 c V,O,-Ni" in aq. EtOH

M3V10028,nH20

(M = Ca, Sr, or Ba, n = 16,24, or 19, resp.) NaAI,V,,038,30H20

[pv, 2o 6l'Ni,V ,O2,,22H 20 Na,Ni,Vl,028,21H20 0 Na4NiVl 0028,23H2

,

V,O,-Nill-Na' in weakly acidic media

I

Na, PVW 0, ,,28H 0 Na,PV, W10040,26H20 i.r., t.d., X Na, 0P2V~Wi2O6 1,42H2O HSPV,W,o040,28.5H20 H,PV,W80,0,25.5H20 7pv4w 8°40,8H20 i.r., t.d., X X,PV~W~~O~O,~H~O x4pVw11040,4H20 (X = guanidinium) isomorphous with K2Zn2analogue (NH,)Ni2Vi 0028,16H2O

d

f

9

h

(a) L. Zurkova, V. Sucha, and M. Dillinger, Coll. Czech. Chem. Comm.,1971, 36, 3788. (b) F. A. Kurmakaeva, Zap. Vies. Mineralog. Obshchestva, 1971,100,523. (c) R. Ripan, V. Cordis, and A. Botar, Rev. Rournaine Chim., 1971, 16, 1717. (d) Y.I. Elfimov, I. Ya. Beznikov, and V. L. Zolotavin, Trudy Inst. Khim. Akad. Nauk S.S.S.R., Ural. Filial, 1971,122,130,134. ( e ) E .F. Tkachand N. A. Polotebnova. Zhur. neorg. Khim., 1971,16, 1913. (f)D. U. Begalieva, A. B. Bekturov, and A. K. Il'yasova, ibid., p. 2748. (9)A. B. Bekturov, A. K. Il'yasova, and D. U. Begalieva, 1zvest.Akad. Nauk Kaz. S.S.R., Ser. khim., 1971,21,4. (h) D. G. Wickham, J . Inorg. Nuclear Chem., 1972,34,2673.

from the reaction of KVO, and K,WO, with formic The orangeyellow M 4 V 2 W 4 0 , , salts, and yellow M 3 V W , 0 , , , n H 2 0 salts (M IS a univalent cation) have been obtained from stoicheiometric mixh r e s of vanadium(v) and tungsten(vI), with appropriate p H adjustment. The [V2W,0,9]4- ion is stable in the pH range 4--7, below this it is converted into other heteropoly complexes, one of which is [ V W , 0 , 9 ] 3 - . Cryoscopic studies and ix., electronic, and X-ray diffraction spectra indicate that these ions have the [M,O,,]"- structures characteristic of the isopolyanions of Nb, Ta, Mo, and W.," The purple heteropolyanions [PV6M,0,8]5- and [ P V , o M 2 0 3 7 ] 7 (M = M o or W) have been prepared and some of their simple salts characteri ~ e d . ~O' n~ acidification the molybdenum ions afford H,PVMo, whereas the tungsten ions form H,PV,W, oO,o. Neutralization of the [PV,M,O,,]S- ions gives [PV,,M,O,,]'and [V2M4OI9]'-. 356 357 358

C. M. Flynn and M. T. Pope, Inorg. Chern., 1972,11, 1950. C. M. Flynn and M. T. Pope, Znorg. Chem., 1971, 10,2524. P. Courtin, Rev. Chirn. minkrule, 1971, 8, 221.


56

The kinetics and stoicheiometry of the oxidation of oxovanadium(rv) by peroxide have been studied and continuous-flow e.s.r. techniques used3s9 to investigate the intermediate which appears to be a vanadium(v) complex with a paramagnetic ligand, formulated as either [ O V 0 0 , a q I 2 + or [VO,( HO,). a s ] - . Six- and seven-co-ordinate \ anadium(v) has been identified by X-ray crytallop-aphy in the pero-uo-complexes (NH,)[V0(02),NH,]360 and (NH,),[O(VO(O,), j respectively. and seven-co-ordination suggested for (NH,)[VO(O,)(H,O)(dipic)].H ?O(dipic = anion of 2.6-pyridinedicarboxylic acid) and Ba[VO,(O,)terpy],, from conductance and spectroscopic The co-ordination about the Lanadium in the [VO(O,j,NH,]- anion can best be described in terms of a pentagonal pyramid, (42), the four oxygens of the two peroxo-groups and the ammonia nitrogen forming the distorted base of the pyramid and the oxo-oxygen occupying the apical position. /O\

0

II

'0\

O/,V\O H ,"

V=O V-0

=

160.6(3)pm

= 188.3(3) pm = 211.0(4) pm

V--N 0--0 = 147.2(4)pm

(42)

The t w o \anadium(v) atoms of the dinuclcar [O(VO(O,),) ,I- anion have an approximately pentagonal-bipyramidal environment. They are linked by a bridging oxygen atom (V-0 = 201 pm, L V--0- V = 98.7") and four peroxo-oxygen atoms (V--0 = 187pm) and these five atoms form a pentagonal plane. At 204pm above this plane, and 161 pm from the metal, is an oxo-oxygen atom. and at 203 pm below the plane is a peroxo-oxygen atom belonging to the other vanadium atom. V,O,. NH,VO,. and VOCI, all give H[VO(HSO,),] when dissolved in disulphuric acid, in which the compiex behaves as a n ~ n - e l e c t r o l y t e . ~ ~ ~ 3 have been prepared Ba, [V021C, O,),] .6 H 0 and Ba [VO(C , 0 ~ ~ 1H.?O and the dehydration of the former at 265°C gives Ba[(V0)2(Cz0,)3].364The have been determined.36s unit cell parameters of (NH,),[V0,(C,0,),],2H20 The equilibrium constant for the formation of [VO,(H,edtaj]- has been estimated366 as 1.66 x 10,. Vanadium(v)-hydroxycarboxylato- and -polyalcohol complexes have been observed in acidic media, and were shown to be primarily tetravanadato-complexes which are broken down by an excess of

,

H. B. Brooks and F. Sicilio, Inorg. Chem., 1971, 10, 2530; T. Ozawa, Y. Kirino, M. Setaka, and T, Kuran, Nippon Kagaku Zasshi, 1971,92,304. 3 6 0 R. E. Drew and F. W. B. Einstein, Inorg. Chem., 1972, 11, 1079. 3 6 L I. B. Svensson and R. Stomberg, Acfa Chem. Scand., 1971, 22, 898. 3 6 2 F. Offner and J. Dehand, Compr. rend., 1971,273, C, 50. 3 6 3 R. C. Paul, J . K. Puri, and K. C . Malhotra, J. Inorg. Nuclear Chem., 1971,33,4191. 3 6 4 J. Gopalakrishnan, T. Palanisamy, M. V. C . Sastri. and V. Srinivasan, Proceedings of the Second Chemistry Symposium, 1970, 1, 183. "' L. 0 Atovmyan and Yu. A. Sokolova, Zhur. strukt. Khim.. 1971,12,934. 3 6 6 J . Lagrange.and P.Lagranpe, Bull. SOC.chim France, 1972. 13. 359


57

reagent to give monovanadato-complexes.36 Complexes of vanadium(v) with phloroglucinol (1 : 1),368 N-arylhydroxamic acids, HON(R ')C(0)R2 (R' = Ph or p-tolyl, and R 2 = Pr, pentyl, PhCH=CH, furyl, nonyl, or n-tridecyl) (1 :2),369 and 2-hydroxy-3-naphthohydroxamic acid (1 : 1 and 1 : 2)370 have been characterized spectrophotometrically. Dibenzoylmethane (HL)and NH,VO, react in acetic acid to form H[VO,L,] which affords [LVO(OR),] (R = Me, Et, Pr', Bu', or But) when treated with ~0~.371

0-and N-Donor Ligands. The [VOCl(L)] complexes formed by treating VOCI, in CCl, with the multidentate Schiff bases (H,L), salen, NN'-bis(salicy1idene)1,2-phenyldiamine, NN'-bis(salicylidene)benzidene, 4,4'-bis(salicylidineimino)diphenylamine, and 4,4'-bis(salicylidineimino)diphenylsulphideand disulphide have been characterized by i.r. and electronic spectroscopy and shown to be non-electrolytes in DMF.372[V0,{4'-(salicylideneamino)acetophenone}] has been prepared and shown to be monomeric6' The Schiff bases (L) benzylideneaniline and anisylideneaniline react with VOCI, to give L,VOC1,373 and Schiff bases derived from salicylaldehyde and substituted aminophenols act as univalent bidentate ligands to form VOCIL, complexes (HL = pRC,H,N:CHC,H,OH-o and R = H, Me, C1, or OMe) or act as a bivalent terdentate ligand to form [VOCIL] (H,L = O-HOC,H,N=CHC~H,OH-O).~~~ S-, Se-, and Te-donor Ligands. The NN'-dialkyldithiocarbamato-complexes [VO(R,NCS,),] (where R = Me or Et, or R,N = 1-pyrrolidine) have been prepared. Their i.r. and mass spectra suggest that the compounds consist of discrete, seven-co-ordinate molecules.375 The [VOSe,13- ion has been identified spectrophotometrically in the course of the reaction between an aqueous solution of [VO4I3- and H2Se gas.376Cu,VX, (X = S, Se, or Te) have been prepared and shown to have a sulvanite-type structure.377

N-Donor Ligands. Whereas small amounts of NH,OH reduce vanadium(v), at high concentrations of NH,OH [VO,(NH,OH),]+ is stable.325Similarly, oxovanadium(v) complexes with HOCH,CH,N[CH,CH(OH)R], (R = Me or Et) have been obtained.378Vanadium(v) reacts379with 8-hydroxyquinoline (Hox) and thiocyanate at pH 4-5 to give a dark-green solid which extracts 367 368

369 370 371

372 373 374

375 376 377

378 3'9

F. Preuss and L. Rosenhahn, J . Inorg. Nuclear Chem., 1972, 34, 1691. S. Ya. Schnaiderman and G . N. Prokofeva, Ukrain. khim. Zhur., 1971, 37,948. J. P. Shukla and S. G. Tandon, J . Indian Chem. SOC.,1972, 49, 83. B. G. Ostrobod and A. L. Markman, Izvest U . Z . Khim. i khim. Tekhnol., 1971, 14, 498. A. V. Savitskii and S. Ya. Skachilova, Zhur. obshchei Khim., 1971,41, 1308. N. S . Biradar and V. H. Kulkarni, Rev. Roztmaine Chim., 1972, 17,481. N. S. Biradar and V. H. Kulkarni, Current Sci., 1972,41,333. N. S. Biradar and V. H. Kulkarni, Rev. Roumaine Chim., 1971,16, 1203. A. T. Casey, D. J. Mackay, R. L. Martin, and A. H. White, Austral. J . Chem,, 1972,2!5,477. A. Miiller, A. Ranade, andV. V. K. Rao, Spectrochim. Acta, 1971,27A, 1973. F. M. Berkovskii, A. A. Vaipolin, N. A. Goryunova, V. M. Orlov, V. I. Sokolova, E. V. Tsvetkova, and G. P. Shpen'kov, Poluprov. Svedin. Zkh. Tverd. Rastvorg., 1970, 159. R. Benes, J. Novak, and S. Sulcek, Coll. Czech. Chem. Comm., 1972, 37, 1118. V. P. R . Rao, and Y. Anjaneyulu, J . Inorg. Nuclear Chem., 1971, 33, 3567.


58

into benzene and is formulated as [VO(NCS),(ox)],Hox with a formation constant of 2.5 x 10'. The i.r. and electronic spectra of VOCl,,nMeCN ( n = 1 or 2) haxe been reported: the v(V=O) stretching frequency decreases from 1035 cm- in VOC1, to 1016 cm- in VOCI,,MeCN and to 992 cm- in VOC1,,2MeCN.380

'

'

Halogendonor Ligands. XeF, reacts with excess VF, at 90°C to give XeF,,VF, as colourless transparent crystals, m.p. 22-28 "C. The i.r. spectrum of the vapour indicates that the compound is completely dissociated in this phase.38' The phase diagram for the HF--VF, system has been presented.382 Dioxotrifluorovanadate salts M;[VO,F,] (M' = Na, NH,, or iNi) and M2[HV02F3],,xH20 (M2 = Co, Ni, or Cu) have been prepared by cation exchange with K,VO,F, or by the reaction of V,O, in excess hydrofluoric acid with M 'CO,, respectively.383 Several salts containing the colourless [VO,F,]- and yellow [VO,CIzl- ions have been prepared. These anions may be formed by mixing a solution of NaVO, with 40% hydrofluoric acid or 259; hydrochloric acid, and appear to have the expected C,, 1.r. spectra of several [VOF,]'and [VOF,]- salts have been reported, together with t.g.a. studies of the decomposition of the latter to V 2 0 s . 3 8 4 Intermolecular charge-transfer spectra have been reported for aromatic hydrocarbons and fluorocarbons with VOC13,and possibly VF,, molecules.385 V,O, reacts with MoOC1, to give a compound nMoOCl,,rnVOC1,, m.p. 96"C.386 Organornetallic Conzpounds. [VO(CH,SiMe,),] is obtained when a petroleum solution of [V(CH,SiMe,),] is passed through a cellulose column, or when VOCl, is treated with less than the stoicheiometric amount of the trimethylsilylmethyl Grignard. This pale-yellow compound, m.p. 75 "C, has been characterized by i.r. and ' H n.m.r. spectra.337

4 Niobium and Tantalum Introduction.-A text describing the analytical chemistry of niobium and tantalum has been p ~ b l i s h e d8.7~ Absorption spectra have been recorded for tantalum atoms isolated in an argon matrix at 4 . 2 K . A complex spectrum was observed388between 228.8 and 504.1 nm which. with only a few exceptions, correlates with the transitions within the ,1,-+ ground state observed for tantalum atoms in the gas phase. The 380

381 382 383 384 385

386

387 388

J. P. Brunette, R. Heimburger, and M. J. F. Leroy, Compt. rend., 1971,272, C, 2147. B. Zemva and J. Slivnik, J. horn. Nuclear Chem.. 1971, 33, 3952. V. K. Ezhov, Zhur. neorg. Khrm., 1972, 17, 661 A. K. Sengupta and B. B. Bhaunik, Z. anorg. Chem.. 1972,390,61. A. K. Sengupta and B. B. Bhaunik, Z. anorg. Chem.. 1971,384, 251. P. R. Hammond and R. R. Lake, J . Chem. SOC.(A), 1971, 3800. S. S. Elineev, I. A. Plukhov, E. E. Vozhdaeva, and R. M. Narzikulova, Doklady Akad. Nauk Tadzh. S.S. R., 1972, 14, 32. I. M. Gibalo, 'Analytical Chemistry of Niobium and Tantalum', Ann Arbor-Humphrey, Ann Arbor, Mich., 1970. W. R. M.Graham and W. Weltner, jun.,J. Chem. Phys.. 1972,56,440.


59

sixth ionization potential of niobium has been reported as 104.5130 and 102.1 eV.t3’ Several studies have been concerned with the chemistry of the + 111 oxidation state of these elements, and the characterization of the first tantalum(III) compounds has been claimed.3s9 The diamagnetic dimer [TaCl,(MeCN),], has been prepared and used to obtain [TaCl,(phen)], [TaCl,(bipy)], and tris(dibenzoylmethanato)tantalum(~~~). NbF, has been characterized as the product of the reaction of Nb and NbF, ( 1 : 1) at 750°C under pressure.390Electrolytic reduction of niobium(v) in ethanol,39 formamide, and dirnethylf~rmamide~~’ can afford preparative concentrations of niobium(1rr)and the new compound niobium(rrr) trilactate has been obtained from ethanol. X-Ray studies have shown that the dimer of niobocene is a metal hydride species [ (x-Cp)Hhb-(p-C,H,),-hbH(rc-Cp)] with bridging C,H, groups and a Nb--Nb bond.393The new complexes [M,(CSiMe,),(CH,SiMe3)4] (M = Nb or Ta) have been shown to contain bridging CSiMe, groups (43) in a fourmembered quasi-aromatic ring, and do not appear to involve a metal-metal bond394. SiMe, M

FHzSiMe3

‘CH,SiMe, Me,Si

Carbonyl Complexes.-The first direct substitution of donor molecules into the co-ordination sphere of metal carbonyl anions has been reported for [M(CO),]- (M = Nb or Ta).223bPhotolytically induced substitution of uniand bi-dentate phosphines has been used to prepare (Et,N) [M(CO),PPh,] and (Et,N) [M(CO),(diphos)]. The preparation of the mixed-metal, seven-co-ordinate complexes [R,M lM2(CO),], [R,M1M2(C0)5PPh3] (R,M1 = Ph,Sn, EtHg, or Ph,PAu; M2 = Nb or Ta), and [Ph,SnM(CO),(diphos)] has been achieved by the reaction of [M2(CO),] -, [M2(CO),PPh3]-,or [M2(CO),(diphos)]- saltswith R,M 1Cl.224 Simple Binary and Related Compounds.-Reviews have been published which describe crystal structures of, and chemical bonding in, the Ta-0 system.395 Structural aspects of niobium and tantalum oxides and oxide fluorides have 389

390 391

392 393 394 395

D. G . Blight, R. L. Deutscher, and D . L. Kepert, J.C.S. Dalton, 1972,87. M . Pouchard, M. R. Torki, G . Demazeau, and P. Hagenmuller, Compt. rend., 1971,273, C, 1093. R. Bosselaar, B. G. Van der Heyden, and R. Mieras, Inorg. Nuclear. Chem. Letters, 1971, 7, 1199; R. Bosselaar, F. Berendes, R. Glasser, and H. V. Bemmel, ibid., 1972, 8, 581. R. Bosselaar, F. Berendes, and R. Glasser, Inorg. Nuclear Chem. Letters, 1972,8, 585. L. J. Guggenberger and F. N. Tebbe, J . Amer. Chem. SOC.,1971,93,5924. F. Huq, W. Mowat, A. C. Skapski, and G. Wilkinson, Chem. Comm., 1971, 1477. V. I. Khitrova and V. V. Klechkovskaya, Metailidy-Str., Svoistva, Primen, 1971, 98.


60

been described, with emphasis on structures which involve both six- and sevenco-ordination of these metals.396 Equilibria in the Nb-0, Nb-N, Nb-C, and Nb-H systems have been studied,39' and the crystal structures and physical and chemical properties of tantalum nitrides, carbides, silicides, and borides and of their multicomponent systems have been reviewed.398 0.uides. The standard free energies of formation of NbO, NbO,, and Nb,O, have been determined electrochemically over the temperature range 1 1001400K as -416 + 0.091; -770 + 0.161; and -1841 + 0.39T 2 2 kJ mo1-', respectively.399 The polymorphism, X-ray data, non-stoicheiometry, thermodynamic data. and oxide -oxide interactions of N b 2 0 , and T a 2 0 , have been d i s c ~ s s e d . ~The " ~ high-temperature form of h , O , can be stabilized by the . crystallographic studies have shown that addition of 2 mol of S C , ~ , X-Ray the crystal structure consists of r - U O , type sheets in which each tantalum(v) is surrounded by a pentagonal bipyramid of oxygen atoms (with Ta-0 = 185-238 pm) which shares edges and corners with distorted octahedral TaO, units (with Ta---0 = 171-238 pm).40'

Halides and O.uyhalide.7. Thermodynamic data hake been presented for MF, compounds (M = Nb or Ta, I I = 1 --5).402 The equilibrium pressure of dissociation of NbBr, into the penta- and tri-bromides. as (5

-

x)NbBr,(s)

%

NbBrx(s)

+ (4

-

x)NbBrS(g)

(s = 2.67--3.03) has been measured403 over the temperature range 275-

365 'C. At a given temperature, this pressure was found to be much lower than that of NbCl,, indicating that NbBr, is significantly more stable than NbCl,. The i.r. spectrum of matrix-isolated NbF, molecules has been reported and shown to be consistent with a C,, monomeric structure.404Thermodynamic functions of NbF, and TaF, as ideal gases at 1 atm and 298--3OOO K have been A mass calculated using the rigid-rotator-harmonic-oscillator spectrometric study has shown that NbF, and TaF, are associated in the vapour phase, ions due to (MF,), (up to n = 4) being observed. Ion-molecule reactions ere eliminatcd by using a molecular beam source.24oMolecular weight data, obtained by mass spectrometric and vapour density measurements, and i.r. and Raman spectra of NbF, and TaF, in the gas phase (250--400°C) are also consistent with these results. Raman spectra confirm that reversible dissociation of the polymers occurs as the temperature is raised. polymeric species being 396 397

398 399 400

401

402

403 404

*O'

M. Lundberg, Chem. Comm. Univ. Stockholm, 1971,22,42,43. G . S. Sokolova and S. F. Yur'ev, Metallovedenie, 1970, 14, 204. K. Surars, Chem.-Ztg.. 1971.95.934. T. Hiraoka, N. Sano. and Y. Matsushita, Trans. Iron Steel I n s t . Japan, 1971, 11, 102. A. Reisman, and F. Holtzberg, 'High Temperature Oxides', ed. A. M. Alper, Academic, New York, 1970, Vol. 2, p. 217. N . C. Stephenson and R. S . Roth, J . Solid State Chem.. 1971.3.145. N. P. Galkin, Yu. N. Turnanov. V. P Korobtsev. G. A. Batarev, V. A. Khokhlov, and A. A. Pavlov, Zhur. j7z. Khim., 1971, 45, 2694, 2695. A. D. Westland and D. Lal, Canad. J . Chem.. 1972,50, 1604. N. Acquista and S. Abramowitz, J . Chem. Phys.. 1972,56,5221. V . P. Seleznev, E.G. Rakov, and V. V. Mikulenok, Zhur.fiz. Khim., 1971,452941.


61

the main constituents of the vapours at their boiling points. The i.r. spectra of the polymers suggest that they involve octahedrally co-ordinated metal atoms with cis-fluorine bridges, since the spectrum of molten NbF, is closely related to that of the gas at lower temperatures, and to that of the solid which is known to involve such a bridging arrangement.406 MBr, and MOBr, (M = Nb or Ta) may be obtained by the reaction of BBr, with anhydrous MCl, or M,O,, respectively. The far-ir. and Raman spectra of these pentabromides and NbOBr, were also reported in this study." The standard heats of formation of NbOF,, TaOF,, Nb02F, and T a 0 , F have been calculated as -1510, -1514, -1138, and -1205 kJ mol-', re~pectively.~'~ Chalcogenides and their Intercalation Complexes. The crystal structure of Nb,Se, has been determined and shown to be similar to that of Ta,S in many respects. Both compounds exhibit a metallic lustre and good electrical conductivity and both involve short metal-metal contacts: in the case of Nb,Se, each metal atom is involved in two Nb--Nb bonds of length 288.5(7) pm. Nb,Se, and Nb,Te, are i s o s t r u ~ t u r a l .An ~ ~ investigation ~ of the Nb-Te system in the composition range from Nb,Te, to Te has led to the characterization of the compounds Nb,Te8 and NbTe,.,09 NbSe, has been prepared by heating finely powdered Nb,O, at 900-1300"C in a stream of H,Se.246 A determination of the crystal structure of the 2H-polymorph of NbSe, has shown that, at room temperature, it has a layered hexagonal structure, with Nb atoms at the centre of a trigonal-prismatic arrangement of Se atoms (Nb-Se = 259.5 pm). At 40 K the compound undergoes a structural transition in which the hexagonal symmetry is maintained although two-thirds of the metal atoms are displaced towards a face of the trigonal prism. This transition is accompanied by anomalies in the electrical resistivity and Hall The 1s-forms of TaS, and TaSe, which involve octahedral co-ordination of the metal atoms, are diamagnetic owing to spin-orbit coupling effects within these d'-configurations. These materials are semiconductors, as are BaTaS, and BaTaSe3.411 Following the discovery of superconductivity in TaS,(py)o,,,32a number of similar intercalation compounds with substituted pyridines have been prepared to study how the structure and properties of the complexes are inter-related. X-Ray studies have shown that the crystals contain the pyridine or substituted pyridine molecules in between the metallic layers of the TaS, lattice. The critical temperature varies between 1.5 and 4.5 K, and generally increases as the number of molecules per TaS, increases.412New sandwich complexes have also been '06

'07

'08

'09

410 '11 '12

L. E. Alexander, Inorg. Nuclear Chem. Letters, 1971, 7, 1053; L. E. Alexander, I. R. Beattie, and P. J. Jones, J.C.S. Dalton, 1972, 210. E. G. Rakov, D. S. Kopchikhin, B. N. Sudarikov, and L K. Marinina, Ref Zhur. Khim., 1971, Abs. 2B844. J. G. Smeggil, J . Solid Srate Chem., 1971, 3, 248. D . L. Smith, A. R. Mochel, J. J. Banewicz, and J. A. Maguire, J . Less-Common Metals, 1972,26, 139. M. Marezio, P. D. Dernier, A. Menth, and G. W. Hull, jun., J . Solid State Chem., 1972, 4,425. W. Geetsma, C. Haas, R. Huisman, and F. Jellinek, Solid State Comm., 1972, 10, 75. F. R. Gamble, J. H. Osieck, and F. J. DiSalvo, J . Chem. Phi r., 1971, a?. 3525

62


formed from NbSe, or TaS, and simple nitrogenous bases, e.g. NbSe,(L),., (L = py, piperidine, Et,NH, or Et,N), NbSe,(en),.,, TaS,(L),,, (L = piperidine, Et,NH, or Et,N), and Ta,S,(en),.,. Their X-ray photoelectron spectra indicate that the electrons are transferred from the nitrogen atom to the metallic layers. and a simple band model can account for the formation of such comp o u n d ~ . ~Crystallographic ’~ and magnetic studies have been reported for M,NbS, (s = 0.33, M = Fe or M n : .Y = 0.25, M = Cr or Mn) and Mn,,,,TaS, formed by the introduction of transition-metal atoms into octahedral holes between the sulphur X-Ray studies of intercalation compounds formed by heating NbSe,, TaS, with Co, Ni, Cu, or Ag at 500--1000°C showed that the chalcogenide layer structure was p r e ~ e r v e d . ~Two ” types of phase have been observed for MxNbS, (M = Ti, V, Cr, Mn, Fe, Co, or Ni). A rhombohedra1 phase may be obtained with x < 0.17 or a hexagonal for x = 0.05--0.50 in which the metal atoms M occupy octahedral Nitrides and 0.uvnitride.y. Crystalline films o f NbN and Nb,N, have been prepared. Electron-diffraction studies showed that the former has a NaC1-type structure and the latter is isomorphous with Ti,05 and Ta,N,.417 The phase O-TaN,., has been prepared by nitriding Ta metal powder with ammonia gas at 85O--12OO0C.Although it could not be obtained pure, the phase was characterized by X-ray diffraction The free energy of formation of Ta,N, has been determined as -272 & 42 kJ mol-’ and that of Ta0,,,,N,~,5 as -396 21 kJ r n 0 1 - l . ~ ~ ~ Arsenides. The crystal structure of Nb,As, has been determined. It consists of a complicated arrangement of Nb,As prisms, with one additional Nb in a cubic hole. and one additional As atom situated in another hole hetueen the prisms.420 Gerittarzide.s and Silicides. A crystal-structure determination of the material pre\iiously formulated as Nb,Ge, has shown that the actual compmition is Nbl,Ge-.42’ The structures of NbFeGe, TaMnGe. and TablriSi h:ive also been investigated . 4 2 2 Borides. Above 1200”C, MB is the principal phase formed by the reaction of M,O, and MB, ( M = N b or Ta).423In the Nb-Ti-B system at 1 10O-18OO0C, Nb,B, and (Nb.Ti)B are in equilibrium with N b solution.26 The compounds 413

“* 4’5

416

*17 418 419 420 421

422 423

B. Bach and J. M. Thomas, J . C . S . Chem. Comm., 1972, 301. B. Van. Laar, H. M. Rietveld, and D. J. W. Ijdo, J. Solid State Chern., 1971, 3, 154. V. L. Kalikhman, E. P. Gladchenko, A. G. Duksina, and A. G. Krupina, Porosh. M e t . , 1971, 11, 57. J. Rouxel, A. Le Blanc, and A. Royer, Bull. SOC.chim. France, 1971, 2019. G. Oya and Y. Onodera, Jap. J. Appl. Phys., 1971, 10, 1485. G. Brauer and E. Mohr-Rosenbaum, Monatsh., 1971, 102, 1311. J. H. Swisher and M. H . Read, Met. Trans, 1972, 3,489. B. Carlsson and S. Rundqvist, Acra Chem. Scand.. 1971, 25, 1742. R. Horyn and R. Kubiak, Bull. Acad. polon. Sci., Ser. Sci. chim., 1971, 19, 185. B. Deyris, J. Roy-Montreuil, A. Rouault, R. Fruchart, and A. Michel, Compt. rend., 1971, 273, c, 47. E. V. Marek, Yu. B. Kuz’ma, and T. Ya. Kosolapova, Porosh. Met., 1971, 11, 70.


63

Ta,Re,B, and TaReB, have been identified in the Ta-Re-B system at 1400°C and characterized by X-ray Hydrides. Replacement of hydrogen by deuterium or tritium in NbH, or (V,Nb)H, results in a more stable compound, the inverse of the normal effect of isotopic Metal Cluster Complexes.-An improved synthesis of Na4[Nb6C1 8] has been obtained by heating an intimate mixture of NbCI,, NaCl, and Nb at 850°C for 6-8 h. The hydrated halides [Nb,C1,,],8H20 and [Nb6Br,,],8H,0 may be prepared conveniently by treating Na4[Nb,C1, 8] or K,[Nb,Br I respectively, with hot concentrated hydrochloric or hydrobromic acid.'L5 clusters have shown MO calculations of the (Nb,C1,,)3 and (Ta,Cl,,), that the upper occuped MO's are predominantly metallic in character and are responsible for the metal-metal bonding.426The crystal structure of (Me,N),[ (Nb6C1,,)C1,] has shown that the anion possesses 0, symmetry with Nb---Nb = 301.8(2), Nb--CI (bridging) = 242.5(2) and 241.2(2). and Nb--Cl (terminal) = 245.7(3)pm. A comparison of these data with those reported for K4[Nb6Cl,,] shows that, on removal of two electrons, the Nb--Nb bonds become longer and the Nb--C1 (terminal) bonds become shorter (cf: similar results for [ (Ta,CI, ,)Cl,]"- clusters, Vol. 1, p. 49). Therefore the two electrons appear to be removed from a bonding MO centred primarily on the metal atoms.42' Roomtemperature 93Nb, 35C1, and n.q.r. spectra of (Me,N),[ (Nb,CI, 2)C16] have,been recorded. An approximate population analysis based on the charges on the chlorine atoms indicated by these results, led to a total of fourteen electrons being available for metal-metal bonding, in agreement with M O treatments of this The compounds (pyH),[ (Nb,ClI2)CI6], (pyH),[ (Nb,Br,JCl,], and (pyH),[ (Nb,Br,C1,)Br6] have been characterized by X-ray crystallography and the exothermic irreversible transition of the second into the third has been Three new mixed-metal cluster species derived from (Ta,CI, ,)"+, [ (Ta,MoCl,,)C1,]2- and 3 - and [(Ta,Mo,Cl, 2)C16]2-, have been prepared by co-reducing 'CaCl, and MoCl, with A1 in a NaC1-AlC1, melt.430 +

+

Niobium(m) and Tantalum(m) Complexes.-The first tantalum(II1) compounds have been reported. TaC1, and MeCN react at 100°C to form the diamagnetic dimer [TaCl,(MeCN),],. The compound exhibits five i.r. bands in the 2300 cm-' region, suggesting more than one environment for the MeCN groups: the structure (44), analogous to that of [WCl,(py),],, has been proposed for the 424

425 426 427 428 429

430

Yu. B. Kuz'ma, V. I. Lakh, B. I. Stadnik, and N. F. Chaban, Dopovidi Akad. Nauk Ukrain. R.S.R., 1971,33A, 849. J. A. Parsons, A. Vongvusharintra, and F. W. Koknat, Inorg. Nuclear Chem. Letters, 1972,8,281. N. S. Voronovich and D. V. Korol'kov, Zhur. strukt. Khim., 1971, 12, 501, 676. F. W. Koknat and R. E. McCarley, Inorg. Chem., 1972,11, 812. P. A. Edwards, R. E. McCarley, and D. R. Torgenson, Inorg. Chem., 1972, 11, 1185. B. Spreckelmeyer and H. G. Von Schnering, Z . anorg. Chem., 1971, 386, 27; B. Spreckelmeyer, C. Brendel, M. Dartmann, and H. Schaefer, ibid., p. 15. 3 . L. Meyer, Diss. Abs. (B), 1971, 31, 5241.

64


compound. Addition of bipy or phen to this compound in MeCN solution precipitates the diamagnetic compound [TaCl,(bipy)] or ['TaCl,(phen)], respectively. Tris(dibenzoylmethanato)tantalum(in) ( p = 1.39 BM) has also been prepared from [TaCI,(MeCN),], by the addition of triethylamine and diben~oylmethane.~~~ Me C .CNMe CNMe

NbF, has been obtained in stoicheiometric yield by heating Nb and NbF, (1: 1) in a sealed gold tube at 750 "C and 3.5 kbar. The compound is a black powder with a cubic Re0,-type structure; it is semiconducting and weakly Preparative paramagnetic with a very weak ferromagnetic concentrations of Nb'" have been obtained by the electrolytic reduction of NbCl, with carbon electrodes in super-dry ethan01,~' formamide, or dimethylf ~ r m a m i d e Addition .~~~ of lactic acid to the ethanolic solution affords the yellow niobium(m) trilactate Nb(C,H,O,),. The reduction of NbV in the presence of Complexon(1v) has been followed33 polarographically at pH 3.2-3.6, and was shown to occur in two irreversible steps: NbV + Nb" --+ Nb"'. [(Cp),NbH,] may be prepared from NbCI,, C,H,Na, and NaBH, under 800 atm pressure. This compound reacts with ligands (L = PMe,, PEt,, CO, or C2H4) to form [ (Cp),Nb(H)L]. Although [(Cp),Ta(H)CO] and [ ( C P ) ~ Ta(H)PEt,] were also prepared, the niobium trihydride exhibits a much greater reactivity than its tantalum analogue.,,, Niobium( IV) and Tantalum( rv) Complexes-NbC1, is reduced in MeCN solution by base metals (e.g.Al) to afford NbCI4,3MeCN, which is a convenient synthetic intermediate for the preparation of other NbW complexes. NbCl,,2L (L = PhCN or DMF) NbC1,,2MeCN,PPh3, [NbCl,,diphos], NbCl,F,xMeCN, [NbCl,(acac),], Nb(OMe),C12,2MeOH, (NMe,),[Nb(OMe)CI,], and K,[Nb(OMe),] have been obtained from NbC1,,3MeCN by ligandexchange reactions. NbBr4,2.65MeCN and TaC1,,3MeCN were also E.s.r. spectra of niobium(iv) dissolved in prepared during this hydrochloric acid and ethanol-hydrochloric acid mixtures have shown that the complex species [NbOC1,I3-, [NbOCl,,H,0]2-, and [NbCl,]'are present, and the latter was isolated as the Cs salt.433bNbCI4,2DMF, NbBr4,431

432

433

G. Popa, R. Lerch, and C. I. Constanta, An. Univ. Bucuresti, Chim., 1970, 19,9. G. W. Parshall and F. N. Tebbe, J . Amer. Chem. Sac.. 1971,93, 3793. (a) R . Gut and W. Perron, J . Less-Common Metals, 1972, 26, 369; (b) D. P. Johnson and R. D. Bereman, J . Inorg. Nuclear Cbem., 1972, 34, 679.


65

2DMF, and Nb14,8DMF have been shown to involve 0-bonded DMF molecules by i.r. studies. The latter compound may be constituted as [Nb(DMF),]I, since no bands attributable to Nb--I were observed, and this formulation is supported by preliminary conductance data in DMF E.s.r. studies of NbC1,,2L complexes (L = DMF, DMA, THA, dioxan, dimethoxyethane, hexamethylphosphoramide, or NN'-diethylformamide) indicate that they adopt a trans-octahedral geometry.435". KSeCN reacts in 6 : l mole ratio with NbCI, in MeCN solution to form TetraK,[ Nb(NCSe),] which involves N-bonded seleno~yanato-groups.~~~~ kistetramethylenedithiocarbamatoniobium(Iv), [Nb{ S2CN(CH2),),], has been prepared by the reaction of NbCI, and NH,{S,CN(CH,),} in MeCN: however, the corresponding tantalum compound was too unstable to be isolated. The niobium derivative was characterized by magnetic ( p = 1.83 BM), i.r., and electronic spectral studies which suggest eight-co-ordinate n i o b i u r n ( ~ v ) . ~ ~ ~ [Nb(S,P(OEt),].] has been obtained by refluxing an excess of Na{S,P(OEt),) and NbX, (X = C1, Br, or I) in toluene for several days. 'The e.s.r., i.r., trigonaland electronic spectra of the compound are consistent with a dodecahedra1 co-ordination about NbLV.Na(S,P(OEt),} and NbX, (X = C1, Br, or I) in a 2: 1 ratio afford reddish-black compounds of composition between [Nb2X,(S2P(OEt),},] and [NbJ, { S,P(OEt),),].'78 [(n-Cp),Nb(SR),] (R = Me or Ph) have been obtained from [(n-Cp),NbCl,] by ligand-exchange reactions. The methyl derivative has been shown to act as a bidentate ligand, and the complexes [ (n-Cp),Nb(SMe),MI2+ (M = Ni, Pd, or Pt) and [I( ~ - C ~ ) , N ~ ( S M ~ ) , M O ( C have O)~ been ] prepared.437The structure of the dimer of niobocene has been shown by X-ray studies to be a dimeric metal hydride with a Nb--Nb bond, [310.5(5)pm], terminal hydrogens and n-Cp groups, and bridging CsH, groups (45). The compound is therefore considered to be a derivative of Nb", and the presence of the Nb-Nb bond is consistent with the diamagnetism of the complex.393

.

434 435

436 437

F

K. Kirksey and J. B. Hamilton, Znorg. Chem., 1972, 11, 1945. ( a ) D. P. Johnson and R. D. Bereman, J . Inorg. Nuclear Chem., 1972,34,2957; (b) T.M. Brown and B. L. Bush, J . Less-Common Metals, 1971, 25, 397. T. M. Brown and J. N. Smith,J.C.S. Dalton, 1972, 1614. W. E. Douglas and M. L. H. Green, J.C.S. Dalton, 1972, 1796.


66

Niobium(v) and Tantalum(v) Complexes.-0-Donor Ligands. A revised compilation of the chemistry of oxoniobates has appeared,438and the general features of the crystal chemistry of titanotantaloniobates have been d i s c ~ s s e d . ' ~ LiNb30ghas been shown to be isomorphous with LiTa30, and thus involves a hexagonal close-packed oxygen lattice with the metal ions in octahedral sites.439aThe corrosion of niobium and tantalum by liquid sodium has been shown to be strongly influenced by dissolved oxygen in the liquid metal. The oxides N a 3 N b 0 4and Na,TaO, have been identified on the surface of niobium and tantalum, respectively, after immersion in liquid sodium containing disSimilarly, niobium and tantalum solved oxygen at temperatures > 300 oC.439b ternary oxides in liquid potassium solutions afford K 3 N b 0 4 and K3Ta04.440 The effect of substituting titanium or tungsten for niobium in M6Nb,o0,0 niobates has been studied.441The crystal structure of LaTaO, has shown that the tantalum(v) atoms are located near the centre of slightly distorted octahedra, the average Ta-0 separation being 200 pm.442The complete series of LnNbO, compounds (Ln = Y or La-Lu except Pm) has been prepared and shown to adopt a distorted form of the scheelite The results of studies of niobates, tantalates, and mixed oxide compounds containing niobium(v) or tantalum(v) are summarized in Table 6 . Table 6

Niobates, tantalates andmixedoxide compounds containing niobium (v) or tantalum(v)

Compound

Source

Properties reported Ref.

Na,NbO, Na,TaO,

Alkali-rich portions of NazO-Nb20, or Na,O-Ta,O, systems oxides in LiF melt

X,new forms

SrLiTa,O,F

M:M;T~,,o,~ (M' = Na or K, M2 = Ba, Sr or Ca) NaBa,Nb,O, SrBaNb,O,,

MNbO, M(NbO313 (M = A1 or In) 438

439

440 441 442

443

Dehydration of compounds from the M(N03),-K3NbO4-Hz0 M(NO,),-KNbO, - H 2 0 systems

U

st, TaO, octahedra b with Ta-0 = 195.1 prn

x,P

C

R

d

C, S ,

X

e

Gmelin Handbook of Inorganic Chemistry, System N o . 49: Niobium, Part B, Section 3 : Oxoniobates (excl. Alkali Niobates), 8th edn., Gmelin Inst. 1971. (a) M . Lundberg, Acta Chem. Scand., 1971, 25, 3337; B. M. Gatehouse and P. Leverett, Cryst. Struct. Comm., 1972, 1, 83; ( b ) C. C . Addison, M. G . Barker, and D. J. Wood, J . C . S . Dalton, 1972, 13. S. Stecura, J . Less-Common Metals, 1971, 25, 1. T. Ikeda, T. Haraguchi, Y . Onodera, and T. Saito, Jap. J . Appl. Phys., 1971, 10, 987. T. A. Kurova and V. B. Aleksandrov, Doklady Akad. Nauk S.S.S.R., 1971, 201, 1095. G. J. McCarthy, Acta Cryst., 1971, B27, 2285.


67


Source

Properties reported Ref

(i) GaNbO, (ii) GaNb,014

Ga,O,-Nb,O,

system

(iii) GaNb, 1 0 2 9 (iv) GaNb490124 InNbO, GaTaO,

In,03-Nb20, system Ga203 TaZO,

InTaO,

h203+ Ta,O,

TIM309

T1203-M205 systems

+

(i) d, m.p., t.d. (ii) d, m.p., t.d.

f

d., m.p., t.d. c, m.p. 1695 "C, t.d., X c, m.p. 1900 "C, t.d., X c, t.d., X

9

h

T14M6021

(M = Nb or Tat Pb3MgNb209

, ,

Ca3Ti3Nb20 Ca,Ti6Nbl,05

+ MgO + Nb20,

X , pyrochlore and perovskite phases

i

CaO-TiO,-Nb,O, system

X

j

ceramic techniques

X

k

st trirutile structure

1 m

X

n

PbO

MIONb10030

+ 6Na, K or Rb) (Mlo = 2Li + 2K + 2Sr, or 4Li + 4Sr, Ba, or Pb) (Mlo = 2Li + 4K + 2La)

(Mlo = 4Li M10Ti2Nb8030

M10Ti4Nb6030

M6TisNb,O3, (M6 = Bi or La) Bi,TiNbO, Ta,CrO, M2Mo3O14

Ta205-Cr203-Cr at 85@-1050°C MOO,-M,O, systems

M12M0033

(M = N b o r Ta)

N b l 4M03044

Bi0.06(W0.82Ta0.18)03

Bi203-W03-Ta20,, 90&1250 "C

Bi, -,(W2-,Tal +x)010-2, Bi2(W0,)3

+ Ta2W08

MNb2O6(M = Mg or Mn) M

,

,

- ,Fe,Nb206 M0-FeO-Nb 0 at high temperatures (M = Ca or Zn) (x = 0,0.2,0.4,0.6,or 0.8) MNb206 (M = Mg, Mn, Fe, Co, Ni, Cu, or Zn) NiNb,O6 NiO + N b 2 0 5(1 :1) NiO Nb205(4: 1) Ni,Nb209 1100--1300°C

+

tungsten bronzes o with tetragonal and perovskite structures tungsten bronzes

p

reduction to

4

MNb203.6,

X

r

ir., X for M = Mg or Fe e, X

S

t

68


Table &continued Compound

AgMWO,,H ?O ( M = N b or Ta)

Zn,Nb,O, 3-ZnN b 2 0 , p -ZnN b 2 0 , Zn2Nb34Ot37 Th, m , w , - x P , (M = N b o r Ta) CeNbO, CeNb,O, Ce2 Nb 1 2 0 3 3 LnNbO,(Ln = Y or Eu)

Properties reported

Source

X Ion exchange with corresponding oxonium salts m.p. 1312°C

ZnO-Nb,O,

Ref U

system

ThO2-WO,-M,O 5 12-1250 "C Ce,03-Nb20, system

LnzO, + Nb,O,. crystallized from PbO + PbF, Ln,NbO-(Ln = La-Dy) Ln,O,-Nb,O, system LnSrn,NbOsolid-state reactions (Ln = Eu-Ln, Sc, or In) 1400 C Ln 4 M 0 Ln,O,+A,O,+M,O, (Ln = La,Dy.Y.Sm,Nd,or Gd. 8OO'C 1 0 h + 12W1300 Ci12h A = LI. Na, or K . M = NborTa) ( a ) M. G. Barker and D. J. Wood, J.C.S.Dalton, 1972, 9. ( b ) A.

m.p. 1405"C, X m.p. 1417"C, X tungsten bronzes

w

X

Y

Y

m.p.X

x

Nil

e, X , pyrochlore structure bb

G. Tutov, V. I. Bader, and I. E. Mytnikova, Kristallografiya, 1972, 17, 406. ( c ) Chan-Van-Thieu, N. N. Krainik, V. A. Isupov, I. G. Ismailzade. I. E. Myl'nikova, F. A. Agaev, and L. S. Volkova, ibid., p. 134. (4L. C. Bobb, I. Lefkowitz, and L. Muldawer, Ferroelectrics, 1971, 2, 217; E. Amzallag, T. S. Chang, R. H. Pantell, and R. S. Feigelson, J. Appl. Phys., 1971, 42, 3254. ( e ) A. M. Golub, A. P. Kvashenko, S. P. Rozhenko. M. M. Nekrasov, and E. V. Galagina, Zhur. neorg. Khim., 1971,16, 1253; A. M. Golub, A. P. Kvashenko, and S. P. Rozhenko, ibid., p . 1244. (f)S . S. Plotkin and V. E. Plyushchev. Izuest. Akad. Nauk S.S.S.R., Neorg. Materialy, 1972,8,319; N. F. Fedorov, I. F. Andreev, R. M.Kasparyan, T.P. Srnorodina, and V. N. Parfenkov, ibid., 1971, 7, 2211. (9) S. S. Plotkin and V. E. Plyushchev, Porosh. Met., 1972, 12, 69. (h) S . S. Plotkin, V. E. Plyushchev, and L. S. Moiseeva, ibid., 1971,7, 2041; S. S. Plotkin and V. E. Plyushchev, ibid., 1972,12,83.( i ) T. N. Verbitskaya, E. N. Laverko, S. M.Polyakov, L. A. Rozorenova, and E. B. Raevskaya, Izoest. Akad. Nauk S.S.S.R., Ser.$z., 1971, 35, 1973. 0') A. Jongegan and A. L. Wilkins, J . Less-Comnion Metals, 1971,25,345. ( k )Chan-Van-Thieu, N. N. Krainik, I. E. Myl'nikova, I. G. Ismailzade, V. I. Isupov, F. A. Agaev, and I. S. Chrnel, lzvest. Akad. Nauk S.S.S.R., Ser.fiz., 1971, 35, 1825. (0 R. W. Wolfe, R. E. Newnharn, D. K. Smith, and M.I. Kay, Ferroelectrics, 1971,3, 1. (m) P. Massard, J. C. Bernier, and A. Michel, Ann. Chim. (France), 1971,6,41. (n)T. Ekstrom, Acta Chem. Scand., 1971, 25, 2591. (0)L. Leparmentier and B. Raveau, Bull. SOC. chim. France, 1971, 2874. ( p ) A . Deschanvres, L. Leparmentier, and B. Raveau, ibid., 1971, 3459. ( 4 ) F. Abbattista and P.Rolando, Ann. Chim. (Italy), 1971, 61, 196. (r) V. V. Deshpande, V. S. Darshane, and R. K. Rao, Current Sci., 1971,40,345: V. S. Darshane, D. A. Braganza, S. P. Kedar. V. M. Phadke. and K. R. Rao, J. Indian. Chrm. SOC.,1972, 49, 109. (s) C. Rocchiccioli-Deltcheff, 1. Dupuis, and C. Wadier, Compt. rend., 1971, 273, C, 1020. ( t ) R. T. Mkrtchyan, S. A. Babayan and G. G. Babayan, Armyan. khim. Zhur., 1971,24, 473. (u) D. Groult, C. Michel, and B. Raveau, Compt. rend., 1972,274, C , 374. (0) R. R. Dayal, J . LessCommon Metals, 1972,26,381. ( w ) J. Y. Feneyrol, R. Sabatier, and G. Baud, Compt. rend., 1972,274, C, 1059. (x) N. A. Godina, T. I. Panova, and E. K. Keler, lzcest. Akad. Nauk S.S.S.K., Nrorg. Mai~riuLj,. 1971.7. 1205. (j,)I. A. Bondar. M. G. Degen. and L. N. Koroleva, ibid., 1971,7, 2215. (z) R. Collongues, M. Perez y Jorba, and G. Tilloca, Monatsh., 1972, 103, 571. (aa) G. Baud and J. P. Besse, Compt. rend, 1971,272. C. 1222. (bb)V. S. Chincholkar, J. lnorg. Nuclear Cheni., 1972,34, 2973. J.C.S.Chem. Comm., 1972. 723.


69

A review of the hetero- and iso-polyanions of niobium and tantalum has been pu bli~hed.,,~ Raman and i.r. spectra of [M,O,,]*- (M = Nb or Ta) salts have been determined and normal-co-ordinate analyses suggest4,, that the ratio of the force constants of the terminal, bridging, and central M-0 bonds is close to 8:4: 1. General methods for the preparation of niobium(v) and tantalum(v)complexes have been discussed and better synthetic routes to some known compounds have been described. [Nb(bpha),Cl], [Ta(bpha),Cl], and [NbO(t),] (where bpha and t are the anions of benzoylphenylhydroxylamine and tropolone, respectively) have been prepared for the first time. NbC1, or TaC1, in methanol react with Hbpha to form the [M(bpha),Cl] complexes. An aqueous solution of niobium(v) which contains tartaric acid to prevent condensation of the hydrolysed metal species affords [NbO(t),] with t r ~ p o l o n e . ~ ~ ~ The new compounds M, [N b(O,),F,],nH,O and M,[Ta( 0,),F4],nH2O ( M = NH,, n = 0: M = K or Na, rz = 1) have been prepared, and i.r. and conductivity studies suggest that they involve eight-co-ordinate metal atoms.447 The stability constants of the niobium(v)-peroxide complexes formed in sulphuric acid solutions have been determined.448 X-Ray studies have shown that oxohydroxobisoxalatoniobic acid pentahydrate, H,[NbO(OH)(C,04)2],4H 20,contains seven-co-ordinate niobium(v), the atom having an approximately pentagonal-bipyramidal environment of oxygen atoms.449 (parH), [NbO(C20,),],3H,0 [par = 4-(2-pyridylazo)resorcinol] has been prepared and characterized in spectroscopic studies2*, The new oxalato-complexes of niobium(v) and tantalum(v) (M), Na, [MO(C,0,)3],4H,O, Na[NbO(C,O,),H,0],4H20, Na,[Nb,O,(OH),(C,O4)2],8H,O, and Na[Nb,O,(OH),(C2O,)],3H,O, have been prepared from aqueous In aqueous media at pH 9.3-10.9 with oxalate: niobate ratios of 1:2 the complexes [Nb,0,(OH),o(C20,)2]6-, [Nb,0,(OH),(C,0,)2]4-, and [Nb202(0H),(C,0,),]2- co-exist. At lower pH values [Nb02(C,0,)2]3and [NbO(OH),(C,0,)2]3 - also exist.,,‘ The interactions of niobium(v) and tantalum(v) with trichloroacetic and adipic acids have been studied and [M(OH),(CC13C02)]. K[M(OH),(CCl,CO,)], and K,[M(OH)(0,C(CH,),C02)4],2H,0 isolated as crystalline solids.45 The reaction of Nb(OEt), and Ta(OEt), with various a-hydroxycarboxylic

444

445 446 447 448 449

450 451

H. T. Evans, jun., Perspect. Struct. Chenz., 1971, 4, 1. R. Mattes, H. Bierbuesse, and J. Fuchs, Z . anorg. Chem., 1971, 385, 230. B. Ilmaier and R. C. Johnson, J . Less-Common Metals, 1971, 25, 323. N. Vuletic and C. Djordjevic, Croat. Chem. Acta, 1970, 43,271. V. P. Vasil’ev, G. A. Zaitseva, and V. G . Malakhova, Zhur. neorg. Khim.. 1971, 16,2142. M. Galesic, B. Matkovic, M. Herceg, and M. Sljukic, J. Less-Common Metals, 1971, 25, 234. M. Muller and J. Dehand, Bull. SOC.chim. France, 1971, 2837. N. Kheddar and B. Spinner, Bull. SOC.chim. France, 1972, 502. Ts. V. Pevzner and I. A. Sheka, Ukrain.khim. Zhur., 1972,38, 295; Ts. V. Pevzner, I. A. Sheka, and Yu. L. Zborovskii, ibid.,p. 239.

‘”

70


acids have been studied and compounds of the type M(OEt),A, M(OEt)A,, and MA,(HA) (H,A = lactic, mandelic, or salicylic acid) obtained for both metals.453 ' H N.m.r. spectra have been used to show the formation of octahedral complexes between Nb(OMe), and Ta(OMe), and donor molecules (e.g. Me,NO, Me,PO. Me,AsO, NH,, or py) at low temperatures. Each octahedral complex is in equilibrium with the alkoxide dimer and the free ligand in solution, and the formation constants of the complexes have been determined. The alkoxides appear to be more reluctant to form complexes and more resistant to reduction than the corresponding Mixed 1 : 2: 2 complexes of niobium(v) with diantipyrylmethane and pyrocatechol or pyrogallol have been characterized by their electronic spectra.455 Magneson(1) and lumogallion form 1 : 1 complexes with niobium(v), with EL,,, = 540 and 546 nm.

S-, Se-. and Te-donor Ligands. NbC1, in MeOH, or KNbO, in aqueous solution with a tartrate buffer (pH = 5.0), reacts with sodium NN-diethyldithiocarbamate to afford [NbO(S,ONEt,),]. 1.r. and mass spectral studies suggest that 446 This this compound consists of discrete, seven-co-ordinate co-ordination number also seems to be characteristic of the complexes [MX(OR'),(S,CZRt),] (M = Nb or Ta: X = C1, Br, or NCS: R' = Me, Et, or Pr'; Z = N, R' = Me, Et, or Bz; Z = P, R2 = M e 0 or C6H110).457 Niobium(v) in acidified perchlorate media reacts with pyrrolidene- and hexamethylene-dithiocarbamates (dtc) to form the [Nb(dtc),]ClO, complexes.458 The tantalum(v) pentakis complex of the latter ligand, [Ta(S,CN(CH,),),], has been isolated, although it probably is not an example of ten-co-ordinat i ~ nCu,NbX4 . ~ ~ ~(X = Se or Te) and Cu,TaSe4 have been prepared and shown to have a sulvanite ~ t r u c t u r e . ~ ' ~

0-, or S-. and N-donor Ligands. 4-(Salicy1ideneamino)acetophenone (HL) reacts with NbCl, inCCl,togive[NbCl,L,],a 1: 1 e l e ~ t r o l y t eThe[NbCI,L'] .~~ and [NbClLIl complexes formed with aromatic Schiff bases (H2L1), N N disalicylidenethylenediamine, bis- [p-(salicylideneamino)phenyl] sulphide, 4,4'bis(salicylideneamino)diphenylamine, bis-[o-(salicylideneamino)phenyl] sulphide. and ( H,L2) N-salicylidene-o-hydroxyanilinehave been prepared, and appear to involve seven-co-ordinate n i o b i ~ r n ( v ) . ~ , ~ Halogeno-c.onzplexes. This section includes studies on oxy- and thio-halide specieb, and 1 : 1 halide adducts with a variety of donor atoms. Phase diagrams for the HF-NbF, and HF-TaF, systems have been presented."' The anti-

458

S. Prakash and R. N . Kapoor, Inorg. Chim. Acra, 1971, 5 , 372. L. G. Hubert-Pfalzgraf, J. Guion, and J. G. Riess, Bull. Soc. chim. France, 1971, 3855. I. M. Gibalo and G. V. Eremina, Zhur. analit. Khim.,1971, 26, 1531. S. V. Elinson and T. I. Nezhnova, Zhur. analit. Khim., 1971, 26, 1535; A. T. Pilipenko, A. I. Volkova, and A. I. Zhebentyaev, ibid., p. 2048. D. C. Pantaleo, Dim. A h . ( B ) , 1971, 31, 5864. K. A. Uvarova, Yu. I. Usatenko, N. V. Mel'nikova, and Zh. G. Kiopova, Zhur. neorg. Khim.,

459

1971, 16, 2137. N. S . Biradar and V. H . Kulkami, J . Less-Common Metals, 1972, 26, 355.

453 454

455 456

457


71

pyrine (A) salts (A,H) [NbF,] and (A,H) [NbF,] have been prepared and their i.r. spectra reported.460X-Ray, d.t.a., and t.g.a. studies have shown that several compounds(4: 1,5: 2,2: 1 , l : 1, and 1:3) are formed in the NbF,-PbF, system.46' MNbOF,,nH,O and MTaF,,nH,O (M = Mn, Co, Ni, Cu, Zn, or Cd, n = 4 or 6) have been prepared, and X-ray studies have shown that the two series are structurally i s o t y p i ~ a lStability . ~ ~ ~ quotients for mono- to hepta-fluorotantalates have been determined in 2M-perchlorate solutions by measuring the free-fluoride concentrations by a lanthanum fluoride membrane electrode. Ion-exchange studies indicate that the complexes are predominantly anionic, and thus [Ta(OH),F,](m+"-s)- species seem likely.463"Equilibrium constants for these complexes in aqueous H F solution have been determined.436b Niobium(v)-fluoro-complexes in aqueous HClO, solutions have been studied by potentiometric titrations and, for high fluorine concentrations and high acidity, evidence has been obtained for the formation of [NbF,I2-, [NbF,I3( K 8 = 1.2 x lo3),and [NbF9I4- ( K , = 1.0 x 104)P64 MgNbF, has been prepared by passing NbF, vapour at 270-300°C over anhydrous MgF, in a silica tube. The equilibrium constant for the thermal dissociation of the compound was evaluated and the heat of formation calculated as -3000 kJ mo1-1.46s The standard heats of formation of Na,[NbF,], K,[NbF,], Na,[TaF,], K,[TaF,], and (NH,),[TaF,] have been determined as -3050 f 22, -3090 f 24, -3210 & 32, -3170 & 18, and -2960 & 18 kJ mol-', respectively.466 The species formed in hydrofluoric acid solutions of tantalum(v) containing hydrazine are pH dependent since this affects both the (N,H,), :(N2Hs)' and and (N,H,)[TaF,] were the [TaF,]- :[TaF7I2- ratios. (N,H,)[TaF,], isolated from anhydrous HF, and (N,H,)[TaF,],H,O and (N,H,),[TaF,] from 45 and 5 % aqueous HF, respectively.467 The geometrical arrangements of halogen atoms in ['TaF,Cl,Br,]- (x + y + z = 6) complexes have been studied using I9F n.111.r.~~~ N.m.r. studies have shown that the most stable mixed-halide complexes formed from the reaction of NbBr, or TaBr, in MeCN at - 10 to - 40 "C are those with identical halogen atoms mutually trans.469 93Nb N.m.r. shifts (from [NbFiI-) in a series of [NbCl,Br,-,]complexes have been shown to correlate with n, as found for other central atoms in mixed halide species, the shielding decreasing as the electronegativity of the halogen increases, e.g. [NbCI,]- and [NbBr,]- ha\ e +

460 461

462

463

464

465

466 467 468

469

V. K. Akimov and A. I. Busev, Zhur. neorg. Khim., 1971, 16, 2404. D. Bizot, Rev. Chim. minhrale, 1971, 8, 797. R. L. Davidovich, T. F. Levchishina, T. A. Kaidalova, and V. I. Sergienko, J. Less-Common Metals, 1972, 27, 35. ( a ) E. W. Baumann, J. Inorg. Nuclear Chem., 1972, 34, 687; ( b ) B. I. Nabivanets and V. V. Lukachina, Ukrain. khim. Zhur., 1971, 37, 581. C . V. Osborn, Diss. Abs. ( B ) , 1971, 32, 3241. G. G. Fedorov, E. G. Rakov, B. N. Sudarikov, and V. A. Starobinskii, Trudy Moskov. KhimTekhnol. Inst., 1970, N o . 67, 89. L. K. Marinina, E. G. Rakov, B. t'.Gromov, and 0.V. Markina, Zhur.fiz. Khim., 1971,45, 1592. B. Frlec and M. Vilhar, J. Inorg. Nuclear Chem., 1971,33,4069. Yu. A. Buslaev, E. G. I l k , and M. N. Krutkina, Doklady. Akad. Nauk S.S.S.R., 1971, 201, 99. Yu. A. Buslaev, E. G . Il'in, and M. N. Krutkina, Doklady Akad. Nauk S.S.S.R., 1971,200, 1345.

72


shifts of 1490 and 2220 rt_ 5 p.p.m. from [NbFb]-."" X-Ray diffraction studies have indicated that the compounds (PCI,)MCl,,AsCl, ( M = Nb, Ta, or Sb) are isomorphous.'" Charge-transfer interactions have been observed between NbF, and MX, ( M = Si. Ge. or Sn. X = alkyl: M = C. Si, or Sn. X = C1) and several organic and for NbCl, and h C 1 , with aromatic hydrocarbons and f l ~ o r o c a r b o n s .In ~ ~these ~ latter cases the enthalpies of interact ion were estimated as 6.3 kJ mol-'. The new complexes [MF,L] (M = Nb or Ta, L = DMSO, EtCN. or CH,ClCN). [TaF5(2-Mepy)]. and [TaFJ4-Mepy),] have been prepared. Their vibrational spectra have been recorded and. together v, ith those of [MF,(MeCN)] and [MF,L2] (M = N b or Ta and L = DMSO or py), discussed in terms of MF,L and [MF,L,J[MF6] structures.473 Neu ' H n.m.r. methods for determining the relative stability constants haLe been developed and used to study the 1 : 1 adducts of NbCl, and TaC1, with a series of ethers, sulphides, and nitriles. The complexes MCI,.R,S are _generally more stable than MCl,R,O, e.g. NbCI,,Me,O + Et,S + NbCl,,Et,S + Me,O, has K = 4.6 in CHCI, at 40°C. Steric factors were shown to be more important thiin inductive effects in determining the relative stabilities of the ether and sulphide adducts, but inductive effects appear to control the relative stability of nitrile adducts, e.g. NbCl,,FCH,CN + ClCH,CN -; NbCl,,ClCH,CN + FCH,CN, has K = 3.6 in CHCI, at -60°C. NbCl, is a weaker Lewis acid towards ethers and nitriles than is TaCl,, e.g. TaCl,,thioxan has 0- and S-bonded isomers. whereas NbCl,,thioxan only forms as the S-bonded isomer. In addition to identifying the 1 : 1 adducts. evidence was obtained for the 2NbCl,.thioxan and 2TaCl,,thioxan adducts."7' NbCl,.POCl, has been identified in the vapour phase of the NbC1,-POCl, system and its AH:o, and AS:,, of dissociation have been shown to be 66 k 4 kJ mol-' and 125 F.4 kJ mol- ', re~pectively."~'(cJ: the heat of formation from solid NbCl, and POCl, of -44 kJ mol- '). The dipole moments, molecular weights, i.r. spectra. and heats of formation of several 1: 1 complexes of NbCI, with esters (EtOAc. PrOAc, BuOAc. PrCO,Et, or C,H,,CO,Et) have been determined."'6 The heats of formation of the acetate complexes are cn. - 1 9 bJ mol- and those with higher acid esters ca. -48 kJ mol LTaCl,,(HMPA)j, [N bOCl 3( H M PA)3. [N bOC1,( 0M PA ) 1, and [TaOCl,( H M PA),] ( H M PA and O M P A = hexa- and octa-methylphosphoramide) have been synthesized, and characterized by i.r. and S - r a y spectroscopy.'-l .

470 471 472

473 414

475

476 47'

Yu. A. Buslaev, V. D. Kopanev, and V. P. Tarasov, Clirrn. Cotnrn., 1971, 1175. H. Preiss and P. Reich, Krist. Tech., 1971, 6 , 375. R. R. McLean, D. W. A. Sharp, and J . M . Winfield, J.C.S. Daltotr, 1972, 676. J. C. Fuggle, D. W. A. Sharp, and J. M. Winfield, J. Fluorine Chem., 1972, 1, 427. A. Merbach and J . C . Buenzli, Chimia ( S w i t . ) , 1971. 25. 222. Helv. Chim. Acta, 1971, 54, 2536, 2543; 1972, 55, 580. A. V. Suvorov, A. M. German, and N . P. Bondareva, Zhur. neorg. Khitn., 1971, 16, 2413. L. V. Surpina, Yu. V. Kolodyazhnyi, and 0. A. Osipov, Zhur. obshchei Khitn., 1971, 41, 1420. R . J. Dorschner, J. Itiorg. Nuclear Chem., 1972, 34, 2665.


73

The chlorine n.q.r. frequencies of the cyanogen chloride adducts, N bCl,,NCCl and TaCl,,NCCl, have been determined and the values shown to be consistent with the crystal structures of the compounds.478MX,,L and 2MX,,L [M = Nb or Ta: X = Cl or Br: L = CH,(CN), or NC(CH,),CN] adducts have been prepared by the direct reaction of the appropriate metal halide uith a solution of L in CCl, or CH,Cl,. Their i.r. spectra are consistent witl, Nbonded nit rile^.^" Similarly, the NbCl,,nL (L = imidazole, 3,5-dimethylpyrazole, benzimidazole, benzazole, or benzothiazole: n = 1,2, or 3 ) compounds have been shown to involve azoles co-ordinated via the unsaturated nitrogen of the azole ring.480 ‘raC1, reacts with PhNCS in hexane or heptane solution to give TaCl,,PhNCS which may be quantitatively converted into TaSCI,,PhNCCl, by refluxing the solution, and into TaCl,.PhNHCSPh by Friedel-Crafts acylaor TaSCl,,PhNCCl, reacts with MNCS (M = K or t i ~ n TaOC13,2MeCN . ~ ~ ~ NH,) in MeCN at 25--60”C to give 4tepwise ligand e~change.,~’NbC1, and TaCl, react with MeSCN and MeNCS to afford MCl,,NCSMe and MCl,,SCNMe, respectively. At 175 “C an equilibrium between the N - and S-bonded species is established.483 MCl,,PR, (M = Nb or Ta: R = Bu or Ph) adducts have been prepared in CCl, solution and, for R = Ph, were shown to react with EtOH or NH, in benzene to give [MCl,(OEt),,PPh,] or MCl,,nNH,,OSC,H, (M = Nb, n = 6: M = Ta, n = 7), respectively. NbCl,,PBu, decomposes at 410°C to give and at 475 “C to give polymeric NbPC12.484

I

Ph

The reactions of 1,2,5-triphenylphosphole(tpp)(46), 1,2,5-triphenylphosphole oxide (tppO), sulphide (tppS), and selenide (tppSe), with niobium(v) and tantalum(v) halides in dry, oxygen-free organic solvents have been studied. The complexes formed were characterized by i.r. and X-ray spectroscopy. The 47 8 479

480

48 1 482 483 484

M. Burgard, J. MacCordick, and E. A. C. Lucken, Znorg. Nuclear Chern. Letters, 1972, 8, 185. M. S. Gill, H. S. Ahiya, and G. S. Rao, Proceedings of the Second Chemistry Symposium, 1970, 1, 239. L. V. Surpina, A. D. Garnovskii, Yu. V. Kolodyazhnyi, and 0. A. Osipov, Zhur. obshchei Khirn., 1971, 41,2279. H. Bohland and F.-M. Schneider, Z . Chem., 1972, 12, 28. H. Bohland and F.-M. Schneider, Z . anorg. Chern., 1972,390, 53. H. Bohland and F.-M. Schneider, Z . Chern., 1972, 12, 63. M. A. Glushkova, M. M. Ershova, N. A. Ovchinnikova, and Yu. A. Buslaev, Zhur. neorg. Khim., 1972, 17, 147.

74


chemistry observed resembles that of the corresponding complexes of PPh, and its analogues. MX, (M = Nb or Ta: X = C1 or Br) and tpp under reflux in CH,Cl, solution form 1 : 1 complexes. The weakness of these M--P bonds is shown by their rapid hydrolysis on exposure to air and the displacement of the phosphole by such solvents as MeCN and Et,O. Protonation of the complexed ligand at the hetero-atom is achieved by HC1, which affords (tppH)[MCI,], and EtOH. The reactions ofthe MX, halides with tppO are summarized

+ (M

X

=

=

Nb or Ta:

C1 or Br) reflux in CbHb.2.5 h

vacuum sublimation

/ Scheme 3

in Scheme 3, where all the complexes involve 0-bonded tppO molecules. With neither the sulphide or selenide was any abstraction of S or Se from P=S or P=Se observed. tppS reacts with a slight excess of TaC1, in benzene to form a-TnCl,.tppS. and in CH,CI, to form f3-TaC15,tppS,0.5CH,C12.tppSe and TaCl, in both CH,Cl, and benzene form the solvated P-phase a d d u ~ t . " ~ ~ M,[NbOF,] (M = Rb or Cs) have been prepared by dissolving Nb,O, in 40 % H F and neutralizing with the alkali-metal carbonate, whereas (NH,),[NbOF,] has been prepared by the thermal decomposition of (NHJ3[NbOF,1?86 ( N H4)3[Nb,O,F9], (NH4)2[NbOF,], (NH4)3[NbOF6],(NH4),[NbOF,],2NH4HF2, (NH,)[TaF,], (NH,),[TaF,], (NH,),[TaOF,], and (NH,)3[Ta,0,F,] have been prepared by the reaction of NbF, or TaF, with aqueous NH4F. 19F N.m.r. spectra were used to follow the changes in state of these fluoro-niobate and -tantalate ions in aqueous solution and in 60% H,O,. The oxide fluorides of niobium gave evidence of partial hydrolysis in the aqueous medium, but in H,O, [NbOF,I2- appeared to be formed.487 X-Ray studies of N,H,[NbOF,],H,O have identified a distorted octahedral structure for the anion! 8 8 485

486

D. Budd, R. Churchman, D. G . Holah, A. N. Hughes, and B. C. Hui, Canad. J . Chetn., 1972,50, 1008; R. Churchman, D. G . Holah, A. N. Hughes, and B. C. Hui, J . Heferocyclic Chetn., 1971, 8, 877. G. Pausewang, Z..Yuturforsch.. 1971,

Xb,1218.

' Yu. A. Buslaev, E. G. Il'in, V. D. Kopanev, and 0. G . Kavrish, Izvest. Akad. Nauk S.S.S.R . , Ser.

"

khitn., 1971, 1139. Yu. E. Gorbunova, V. J. Pakhomov, V . G. Kuznetsov, and E. S . Kovaleva, Zhur. strukt. Khitn., 1972, 13, 165.


75

Substitution of F for 0 in KSr,Nb,O,, has led to the formation of tetragonal tungsten bronzes.489 The Na-TaV-0-F system at 700 "C has been studied; and the compounds NaTaO,F,, Na,Ta,OSF,. Na,Ta,O,F,, NaTa,O-F,, Na,Ta,O,,F,, and Na,Ta80,,F4 were characterized, and at 1100°C NaTa,O,,F was ob~erved.~"Na,TiNbO,F,, NaSnTiNbO,F, Sn,TiNbO,F, and TlTiNbO,F, have been prepared by heating MF (M = Na or Tl), SnO, and/or TiO,, and Nb,O, at 700°C. A'-Ray studies have shown that the compounds have the pyrochlore s t r u ~ t u r e .Structural ~~' studies have also been reported for MNb,O,F (M = Rb, Cs, or T1) and T1TiNb04F2.492 NbOC1,,2DMSO has been prepared and ~haracterized.,,~" N-Donor Ligands. Mono- and bis-diethylamido-niobium(v) and -tantalum(v) fluorides, MF,NEt, and MF,(NEt,),, may be conveniently prepared by treating MF, or MF,,OEt, with a small or a large excess, respectively, of trimethylsilyldiethylamine at 20 "C.Their i.r. spectra of these complexes suggest a dimeric fluoro-bridged structure. They are weaker Lewis acids than the parent pentafluorides and, although 1: 1 complexes with py or 4-Mepy are formed, no isolable complexes with MeCN or E t 2 0 could be obtained. NbF, reacts with trimethylsilyl chloride in Et,O to give labile niobium(v) chlorofluoride species and finally NbC1,,Et,0.493 Ligand-exchange reactions of TaOC13,2MeCN and TaSCl,,PhNCCl, withMNCS (M = K or NH,) in MeCN at 25--60°C have led to the complexes TaOCln(NCS),- +2MeCN (n = 0, 1, or 2), M[TaO(NCS),],2PhNC12, Ta(NCS),,PhNCCl,, and M[TaS(NCS),],PhNCCl, being isolated. Electronic and i.r. spectra indicate that these complexes are six-co-ordinate in solution and involve exclusively N-bonded terminal t h i o c y a n a t o - g r ~ u p s .K[Ta~~~ (NCSe),] has been prepared by reaction of TaC1, and KSeCN (1:6 in MeCN), and spectroscopic studies indicate N-bonded seleno~yanato-groups.~~~~ Organometallic Complexes. The elimination-stabilized alkyl, [Ta(CH,CMe,),Cl,], has been isolated.494 A new type of carbon bridging group, CSiMe,, has been identified by X-ray crystallography in (43) (see p. 59). The niobium compound and its tantalum analogue were obtained by the reaction of the pentachloride with Me,SiCH,MgCl in ether.394 [(IT-Cp),Nb(SR),] (R = Me or Ph) may be oxidized by iodine or by treatment with HBF, to give the purple [(.n-Cp),Nb(SR),]+ and orange [((ITCp)2Nb(C1))20]2+complexes, re~pectively.~~' The preparation and reactions of [ (Cp),NbH,] have been described earlier432(p. 64).

489

490 491 492

493 494

J. Ravez, D. Tourneur, and P. Hagenmuller, Materials Res. Bull., 1972, 7, 473. J. P. Chaminade, M. Pouchard, and P. Hagenmuller, Compt. rend., 1971, 273, C, 984. J. P. Miranday, G. Gauthier, and R. De Pape, Compt. rend., 1971, 273, C , 970. G. Ory, J. L. Fourquet, C. Jacoboni, J. P. Miranday, and R. De Pape, Cotnpt. rend., 1971,273, C, 747. J. C. Fuggle, D. W. A. Sharp, and J. M. Winfield, J . C . S . Dalton, 1972, 1766. W. Mowat and G . Wilkinson, J . Organometallic Chern., 1972, 38, C3.5.

76

Inorganic Chemistry of the Transition Elements 5 Chromium

Introduction.-The reference literature for organochromium compounds has been supplemented . 4 9 Interesting new developments in chromium chemistry which have been reported this year include the preparation of butadienetetracarbonylchromium by treating chromium atoms with butadiene, followed by subsequent treatment with C 0 . 4 9 6 The first ring-exchange reactions involving metallocenes have shown that chromocene is quite labile in this respect.255 [Cr [N(SiMe,),),(THF),] has been prepared and shown to have the trans square-planar configuration. In contrast, [Cr(NO) (N(SiMe,), 13] has a pseudo-tetrahedral structure with a linear Cr-N-0 system.497 A trigonalbipyramidal geometry about chromium(111) has been confirmed in CrCI,,2Me,N by X-ray studies2 and suggested in Cr(tdeH)Cl, [where tdeH, = thiodiethanol, S(CH2CH,0H),] from spectroscopic The novel complex [CI(H,O),(NCS)(SCN)]T . involving Y- and S-bonded thiocyanato-groups. has been prepared4" in solution by the reaction of (Fell'NCS),aq with Cr".aq in the presence of free NCS-. Irradiation of aqueous solutions of [Cr(NH,),N312+ at pH 1 in the ligand to metal charge-transfer region leads to redox decomposition and is the first example of photochemical redox decomposition of a chromium(iri) complex.500Oxygen molecules in the singlet excited state are released from potassium perchromate, K,Cr0,.501 Several new chromium-(rIi) and -(Iv) alkyl complexes have been characterized4. 5 . 33'. 5 0 2 and it is interesting that the latter oxidation state can be obtained readily with carbon as the ligand donor atom.

Carbonyl Complexes.-A detailed investigation of the electrochemical synthesis of [Cr(CO),] has been reported. The electrochemical reduction of chromium(rir) complexes in anhydrous solvents saturated with C O under medium pressure affords the carbonyl in good yields, e.g. 852; from [CrCl,(py),] in py at 85°C and 60atm.503The standard heat of formation of [cr(co)(,] has been deter13 kJ mol-' by measuring the heat of d e c o m p o s i t i ~ n . ~ ~ ~ mined as -935 Molecular core binding energies for some chromium complexes, including [Cr(CO)(,], have been reported and, as shown by an earlier study, the values cuggest that in the synergic bonding scheme x-bonding is more extensive then o-b~nding.~'~

*

495

496 497 498

499 500 'O'

'02

504 '05

'Gmelin's Handbook of Inorganic Chemistry,' supplementary work, vol. 3. Organochromium Compounds, 8th Edn., Gmelin Institute, 1971. E. K. von Gustorf, 0. Jaenicke, and 0. E. Polansky, Angew. Chem. Internut. Edn., 1972, 11, 532. D. C. Bradley, M. B. Hursthouse, C. W. Newing, and A. J. Welch, J.C.S. Chem. Comm., 1972,567. B. Sen and D. A. Johnson, J . Inorg. Nuclear Chem., 1972, 34,609. L. D. Brown and D. E. Pennington, Inorg. Chem., 1971, 10, 2117. A. Vogler, J . Amer. Chem. SOC.,1971,93, 5912. J. W. Peters, J. M. Pitts, jun., I . Rosenthal, and H. Fuhr, J . Amer. Chem. Soc., 1972, 94, 4349. T. Tsuda and J. K. Kochi, Bull. Chem. SOC.Japan, 1972,45,648. M. Gueinazzi, G. Silvestri, S. Gambino, and G . Filardo, J.C.S. Dalton, 1972, 927. H. A. Skinner and Y. Virmani, Rev. Roumaine Chim., 1972, 17,467. D. T. Clark and D. B. Adams, Chem. Comm., 1971. 740; Chem. Phys. Letters, 1971, 10, 121.


77

The photochemistry of [Cr(CO),] has been investigated in several studies. Flash photolysis of cyclohexane solutions of [Cr(CO),] affords two species; one has a Amax of 470 nm and a lifetime of 5 ms and the other, A,, = 440 nm, has a lifetime > 1 s.506The relationship between photolysed species of [cr(co)6] and photochemical substitution reactions described in Scheme 4 has been suggested from i.r. and U.V.spectroscopic studies of matrix-isolated species.5o7

1

strong ligand

co

Scheme 4

In argon and methane matrices at 20 K, co-ordinatively unsaturated C40 [Cr(CO),] may be obtained having absorptions at 542 and 492 nm, respectively. The shift to higher energy of the latter is attributed to a [(OC),Cr]-CH, may be regenerated by irradiation with light correspondinteraction. [cr(co)6] ing to the U.V.absorption of the pentacarbonyl. Essentially quantitative conversion of [Cr(CO),] into C,,[Cr(CO),] has been achieved by irradiation with U.V.light (A > 286 nm) in pentane-methylcyclohexane at 90 K. Irradiation with longer-wavelength light (A > 323 nm) reverses the cleavage reaction. The molecules are stable at this temperature in the dark for at least 24 h, but the parent hexacarbonyl is regenerated rapidly above the softening point of the glass.508Co-condensation of Cr atoms with CO in an excess of argon at 17 K appears to afford [Cr(CO),] (x = 1-6). On warming there is a rapid combination of carbonyls having x = 1 - 4 with CO: however, the rate of production of [Cr(CO),] from [Cr(CO),] is relatively slow unless the system is irradiated,507b as observed in other matrix-isolation studies. [Cr(CO),] catalyses the condensation of isocyanates with aldehydes to give imines in 90-100% yields.509 Na,[Cr,(CO),,] reacts with Hg in T H F at 130 140°C uithin 4 weeks to form Na,[ (OC),CrHgCr(CO),], which has been characterized by vibrational s p e c t r o s ~ o p y . ~Secondary '~ ions [Cr,(CO),]+ (rn = 1--3 and n = 0--14), 507

'08

510

J. M. Kelly and A. Morris, Rev. Latinamer. Quim., 1972,2, 163. (a) M. A. Graham, R. N. Perutz, M. Poliakoff, and J. J. Turner, J . Organometallic Chem., 1972, 34, C34; (b) M. A. Graham, M. Poliakoff, and J. J. Turner, J . Chem. SOC.( A ) , 1971,2939. M. J. Boylan, P. S. Braterman, and A. Fullerton, J. Organometallic Chem., 1972, 31, C29. J. Drapier, A. J. Hubert, and Ph. Teyssit, J.C.S. Chem. Comm., 1972, 484. H. Behrens, H. D. Feilner, E. Lindner, and D. Uhlig, Z. Naturforsch. 1971, 26b, 990.

78


considered to arise from ion-molecule reactions, have been observed in the mass spectrum of [ c r ( c o ) , ] at 10- 5-io-6 Torr and 35--10O0C. Confirmation of the mode of formation of these species was obtained when [Cr(CO),] and [Mo(CO),] vapours were mixed in the gas inlet and produced [CrMo(CO),] ( n = 5-7).511 Several studies of natural abundance I3C n.m.r. spectra ofchromium carbonyl complexes have been reported this year.' l 2 - ' I 4 The technique is able to distinguish between different stereochemicai environments of carbonyl groups in a compound since the 6(' ,C=O) shift appears to be primarily dependent on the steric and electronic requirements of other ligands.'I2 A good correlation of the 6(13C"O) shift with the corresponding Cotton-Kraihanzel stretching force constant has been observed for several Cr, Mo, and W carbonyl complexes. n-bonding This suggests that for a given metal the changes in the M-C--0 exert a dominant influence on the 13C chemical shifts.513Consistent with this, in [I(OC)5MC(X')X2] complexes ( M = Cr, X' = OMe, X 2 = Me or Ph: M = W. X' = OMe, SMe, NHMe, X2 = Me) the I3C resonances for the trans-COare found downfield from those for cis-CO. The carbene carbon atoms in these complexes are extremely deshielded, the resonances being far outside the normal range for organic compound^.^ 14' Halogvno-co,nplescs. The results of molecular orbital calculations of the electronic structure of [Cr(CO),-xX,] (X = C1, Br, or I, .Y = 1 or 2) and related manganese and iron species have been correlated with the corresponding carbonyl stretching force constants. It is suggested that the direct donation from the halogen's o-orbital into the cis-carbonyl's x*-orbitals is the most important mechanism by which a change in halogen effects a change in C-0 force constant . 5 Cr(CO), reacts with the quaternary phosphonitrilic iodide, N,P,Me,I, t o give (N,P4Me9) [Cr(CO),I], and i.r. and 'H n.m.r. spectra indicate some donoracceptor interaction between the ions. The compounds (Me,N),[ (OC),CrX,Cr(CO),] (X = F, C1, or Br) have been prepared by refluxing [Cr (CO),] and Me,NX. These reactions are very rapid and demonstrate the strong Lewis acid properties of [ (arene)M(CO),] molecules and thus provide support for the view that these molecules serve as effective Friedel-Crafts catalysts by generating carbonium ions. The [(OC)3CrX,Cr(CO)3]3- ions are probably triply bridged species (47).5 '

511

'12 '13

'16 517

J. Miiller and K. Fended, Chem. Ber., 1971, 104, 2199; C. S. Kraihanzel, J . Conville, and J. E. Sturm, Chem. Comm., 1971, 159. L. F. Farnell, E. W. Randall, and E. Rosenberg, Chem. Comm. 1971, 1078. 0. A. Gansow, B. Y. Kimura, G. R. Dobson, and R. A. Brown, J . Amer. Chem. Soc., 1971, 93, 5922. ( a ) C. G. Kreiter and V . Formacek, Angew. Chem. Infernat. Edn., 1972, 11, 141; ( b ) B. E. Mann, Chem. Comm., 1971,976. M . B. Hall and R. F. Fenske, Inorg. Chem., 1972,11, 1619. N . L. Paddock, T. N. Ranganathan, and J. N. Wingfield, J.C.S. Dalton, 1972, 1578. J. F. White and M. F. Farona, J . Organometallic Chem., 1972, 37, 119.


79

0-,S-, and Se-donor Ligands. The doubly bridged p-hydroxo-complex (Me,N),[(OC),Cr(OH),Cr(CO),] may be prepared by refluxing [Cr(CO),] and Me,NOH in ethanol.’ l 7 The carboxylato-complexes [RCO,Cr(CO),] - (R = CF,, C,F,, or C,H,) have been obtained as their bis(tripheny1phosphine)iminium (Ppn) salts by the reaction of (Ppn),[Cr,(CO),,] with Ag(0,CR) or Hg(O,CR)* in CH,Cl, at room temperat~re.’’~

Thallium monothiothenoyltrifluoroacetone (Tlttas) reacts with (Et,N)[Cr(CO),Cl] to form the red compound (Et,N) [Cr(CO),(ttas)] involving a unidentate S-donor ligand. The compound evolves CO on heating to form the purple derivative (Et,N) [Cr(CO),(ttas)], the anion having a cis-octahedral structure with the ttas acting as a bidentate 0- and S-~helate.”~Electronimpact ionization potentials of [Cr(CO),L] [L = DMSO, S(CH2),, or OS(OCH,),] have been shown to correlate well with the ligand (L) ionization potentials, and the results have been discussed in terms of 0-and n-bonding effects. The mass spectra of the complexes were also e x a ~ p i n e d . ’ ~ ~ The thiazolidine-2-thione (ttz) (48) pentacarbonyl complex of chromium, [Cr(CO),(ttz)], has been prepared by U.V. irradiation of a solution of [Cr(CO),] and ttz. Spectroscopic studies indicate that the ligand is co-ordinated via the S atom of the thioketone The methylthio-bridged complexes [M( SMe)Cr(CO),] [M = (x-Cp)(CO),Fe, (n-Cp)(CO),Mo, (n-Cp)(CO),W, or Ph,PAu] have been prepared by the reaction of MeSM with [Cr(CO),], or MCl with [Me,Sn(SMe)Cr(CO),], and characterized by their i.r. and ‘H n.m.r. spectra.’ 22 The complexes [ (L-L)M(SR),Cr(CO),], [(L-L) = diphos or diars, M = Pd or Pt, and R = Me or Ph] have been prepared by the 1: 1 reaction of [(L-L)M(SR),] and [ (norbornadiene)Cr(CO),]. 1.r. and diffuse reflectance spectra suggest that the (L-L)M(SR), groups function as simple bidentate disulphide ligands and there is no evidence for any M-Cr bonding.523‘The addition of 518

519 520

52 1

522 523

W. J. Schlientz, Y. Lavender, N. Welcman, R.B. King, and J. K. Ruff,J . Organometallic Chem., 1971, 33, 357. G. H. Barnett and M. K. Cooper, Chem. Comm., 1971, 1082. G. Distefano, A. Foffani, G. Innorta, and S. Pignataro, Internat. J. Mass Spectrometry IoriPhys., 1971, 7 , 383. D. DeFilippo, F. Devillanova, C. Preti, E. F. Tragu, and P. Vigllno, Znorg. Chim. Acta, 1972,6, 23. W. Ehrl and H. Vahrenkamp, Chem. Ber., 1972, 105, 1471. P. S. Braterman, V. A. Wilson, and K. K. Joshi, J . Organometallic Chem., 1971, 31, 123.

ao

Znorgnnic Chemistry of the Transition Elements

tertiary phosphine and arsine chalcogenides (L = Me,PS, Me,PhPS, Ph,PS, Me,AsS, or Me,PhPSe) to u.v.-irradiated solutions of [cr(co)6] in T H F has produced the new [Cr(CO),L] complexes. Their i.r. spectra consist of five well-spaced carbonyl stretching frequencies, suggesting that they involve a non-linear Cr-S(SekP(As) bond.524

II

S

1.r. spectra (700-300 cm- ’) have been recorded for solutions of some cis-

[(bidentate)Cr(CO),] complexes (where bidentate is a chelating ligand bonding through S, N, P, or As donor atoms). The changes in the values of v(M-C) were rationalized in terms of the o-donating ability of the ligand, and a parallel was observed between these values and the rates of reaction via a path involving rate-determining dissociation of CO.,,,

N-, P-. As-, and Sb-donor Ligands. [Cr(CO),(bipy)] has been reduced by sodium in THF. Electronic and e x . spectra of the resulting complex suggest that it involves co-ordination of the uni-negative ion of bipy. The complex loses CO to afford either a five-co-ordinate complex or a dimeric The rate constants for the first-order thermal decomposition of [Cr(CO),] amine complexes have been shown to decrease with increasing pK, of the amine, consistent with Cr-N bond cleavage being the rate-determining step. Related compounds involving unsaturated amine ligands, e.g. py, are much more stable than would be expected from their pK, values, suggesting some Cr-N back-bonding for these ligand~.~,’Hydrazine has been identified as a bridging ligand in the complexes [(OC)SCrN2H,M(CO),], (M = Cr or W) prepared by treating [Cr(CO),THF] with [ (OC),MN,H,] or N,H,.’,* [Cr(CO),] reacts with 1,8-naphthyridine, 2-methyl-l,8-naphthyridine, and trans-decahydro- 1,s-naphthyridine (L) to form [Cr(CO),L], [Cr(CO),L,], and Cr[ (CO),L] complexes, the latter involving L as a bidentate ligand. With 2,7-dimethyl-l,S-naphthyridine and 2,9-dimethyI-l,lO-phenanthroline(L’), [Cr(CO),L’] complexes were obtained.529 The pyridine-2-carboxyaldehyde imines (49) react with [Cr(CO),] under U.V. irradiation to afford the intensely coloured complexes (50). Reaction of the 524 525

526

52’

528 529

E. W. Ainscough, A. M. Brodie, and A. R. Furness, Chem. Comm., 1971, 1357. G. R. Dobson and R. A. Brown, J. Inorg. Nuclear Chem., 1972,34,2785; Inorg. Chim. Acta, 1972, 6.65. Y . Kaizu and H. Kobayashi, Bull. Chem. SOC.Japan, 1972,45,470. R. J. Dennenberg and D. J. Darensbourg, Znorg. Chern., 1972, 11, 72. D. Sellmann, 2.Naturforsch., 1971, 26b, 1070. T. E. Reed, Diss. A h . ( B ) , 1971, 32, 1430.


81

latter (R = Pr') with Ph,P gives (51). Since the phosphine occupies a site cis to the azomethine group the complex may exist in enantiomeric isomers.530 [Cr(CO),] reacts with the terdentate N-donor ligands [T = bis(2-pyridylmet h yl)amine, bis-(2-pyridylmethy1)methylamine, or bis(2-pyridylet hyl)amine] to form thefac-[Cr(CO),T] derivative^.^,'

CH:NR 0 R

=

Me, Pr', cyclohexyl, or OH

(49)

(50)

(51)

The photoelectron spectra and ionization potentials of [Cr(CO), PF,] and other PF, carbonyl complexes have been determined. They indicate that PF, generally appears to be a more charge-withdrawing group than C0.532 Bis(t-butyl)fluorophosphine, the first stable dialkylfluorophosphine, and the corresponding difluorophosphine have been studied as potential ligands. Complexes [Cr(CO),L] (L = Bu'PF, or BuiPF) were prepared by irradiating a THF solution of L and [Cr(CO),]. 1.r. and n.m.r. data of these and related complexes suggest the order PF, > Bu'PF, > BuiPF for the Tc-acceptor character of the phosphines, and W(CO), > Mo(CO), > Cr(CO), 2 Ni(CO), for the n-donor power of the metal carbonyl fragment.533The crystal structure of [Cr(CO),(diphos)] has been determined534oand the discrete molecules have been shown to involve cis Cr-P bonds of length 236.0(2)pm.The relative lengths of the Cr-C bonds, 183.1(7) and 188.4(7) pm, trans and cis to P, respectively, are consistent with the phosphine groups being poorer Tc-acceptors than CO. [225.2(1.0) Similarly, the shorter Cr-P bonds in tran~-[Cr(C0)~{P(OPh)~~,] pm]534b than in [Cr(CO),P(OPh),] [230.9(1.0) pm] are consistent with P(OPh), being a poorer n-acceptor than CO. [Cr(CO),(diphos)] is oxidized with NOPF, to form [Cr(CO),(diph~s)]PF~.~~~ The displacement of THF in the photochemically generated species [Cr(CO),THF] by Et,NPF, or the oxidation of [Cr,(C0),,]2- by HgCl, in the presence of Et,NPF, affords [Cr(CO),PF,NEt,]. Treatment of this complex with HBr forms [Cr(CO), PF, Br] . 530

531

532 555

53*

535 536

G

H. Brunner and W. A. Herrmann, Chem. Ber., 1972, 105,770. J. G. Dunn and D. A. Edwards, J . Organometallic Chem., 1972, 36, 153. J. Muller, K. Fenderl, and B. Mertschenk, Chem. Ber., 1971, 104, 700. 0.Stelzer and R. Schmutzler, J . Chem. SOC.(A), 1971,2867. (a) M. J. Bennett, F. A. Cotton, and M. D . LaPrade, Actu Cryst., 1971, B27, 1899; (6) H. S. Preston, J. M. Stewart, H. J. Plastas, and S. 0. Grim, Inorg. Chem., 1972, 11, 161. B. F. G. Johnson, S. Bhadwi, and N. G. Connelly, J . Organometallic Chem., 1972,40, C36. W. M.Douglas and J. K. Ruff, Synth. Inorg. Metal-org. Chem., 1972, 2, 151.

82

Inorganic Chemistrv of the Transition Elements

The sensitivity of the Cr-CO bond, and the relative inertness of the Cr---PR, bond. to photolytic cleavage is illustrated by the photochemical preparation of trans-[Cr(CO),( PPh,),] from [Cr(CO),PPh,] and PPh,.j3' In an attempt to obtain new zerovalent derivatives of chromium, the U.V. irradiation of mixtures of [Cr(CO),] and (PrO)PF,, (MeO),PF, (MeO),PMe, (MeO)PMe,, and PMe, in pentane have been studied. Although the reaction with the latter did not proceed beyond cis-[Cr(CO),(PMe,),], the reaction was shown to be generally efficient for obtaining the penta- or hexa-substituted derivatives, most of which were isolated and characterized by their i.r. and n.m.r. [(Me,Sn),PCr(CO),] reacts with Ph,PCI (1: 3) at room temperature under Ar to form [(Ph,P),PCr(CO),], which may also be obtained directly by the U.V.irradiation of a solution of (Ph,P),P and [Cr(CO),].i3s, [C,H,Cr(CO),(P(C,H,FeC,H,),)] may be prepared inasimilar manner from [C,H,Cr(CO),] and [ (C,H jFeC5H4)3P].540The bifunctional phosphorus ligand P(OCH,),P has two different phosphorus atoms but is unable to chelate to a metal atom because of its rigid bicyclic structure. [{ P(OCH,),P)Cr(CO),] has been prepared and characterized by its i.r., mass, and 'H and , ' P INDOR n.m.r. spectra.', . The reactions of the ligands (L) PhP(CN), and R,PCN (R = Me, Ph, OEt, or NMe,) with [ (norbornadiene)Cr(CO),] have been found to produce the yellow [Cr(CO),L], complexes, which have been assigned the structure (52)

'

0 C

C

c

c

0

0

0

from ir., 'H n.m.r., and mass spectral studies. These bridged compounds react further with another molar equivalent of L or (MeO),P to form [Cr(CO),L,] or [Cr(CO),L P(0Me),] complexes.542 The deprotonation of Cr(CO),PPh,H with n-butyl-lithium has been followed in i.r. spectral studies, the parent compound and its lithio-derivative having v(C--0) absorptions at 2066m and 1944sb,and 2023m and 1925sb cm-', respectively, the lower frequencies of the latter corresponding to a greater 537

538 539

54u

541

542

G. Schwenzer, M. Y.Darensbourg, and D. J. Darensbourg, Znorg. Chem., 1972, 11, 1967. R. Mathieu and R. Poilbanc, Znorg. Chem., 1972, 11, 1858. H. Schumann and E.von Deuster, J . Organornetallic Chem., 1972, 40,C27. A. N. Nesmeyanov, D. N. Kursanov, V. N. Setkina, V. D. Vil'chevskaya, N. K. Baranetskaya, A. I. Krylova, and L. A. Glushchenko, Doklady Akad. Nauk S.S.S.R., 1971, 199, 1336. D . A. Allison, Dim. A h . ( B ) , 1971, 32, 798. C . E. Jones and K. J. Coskran, Znorg. Chem., 1971, 10, 1664.

T h e Early Transition Metals

83

negative charge on the metal. Me1 reacts with the lithio-compound to give [Cr(CO), PPh2Me].543 The complex [c~s-C~(CO),(CF,PH,)~]has been prepared from [(norbornadiene)Cr(CO),] and excess CF,PH, at 60 "C and, in contrast to the spontaneous inflammability of the free ligand, the complex is not noticeably air sensitive. N.m.r. spectra were reported for this and a series of related molybdenum and tungsten derivatives, and the values of the P-P coupling const ants discussed. 44 Chromium carbonyl complexes of the tritertiary phosphine (Ph,PCH,CH,),Ph (PPP),the isomeric tetra tertiary phosphines Ph,PCH ,CH ,P(Ph)CH,CH,P(Ph)CH,VH,PPh (PPPP) and (Ph2PCH2CH2),P (PP,), and the hexatertiary phosphine (Ph,PCH2CH2),PCH,CH,P(CH,CH,PPh,), (P2P4) have been prepared.545In [(PPP)Cr(CO),] the tritertiary phosphine functions as a bidentate ligand and in [(PPP)Cr(CO),] as a terdentate ligand. These complexes may be obtained by reaction of the ligand with [(norbornadiene)Cr(CO),] or [(cycloheptatriene)Cr(CO),], respectively, or with Cr(CO),, whence both complexes are obtained. [Cr(CO),] reacts with PPPP or PP, in boiling toluene to afford the [(tetraphos)Cr(CO),] derivatives involving with terdentate phosphine ligands. Reaction of [(n~rbornadiene)Cr(CO)~] these ligands affords [(tetraphos)Cr(CO),] with a bidentate phosphine. [Cr(CO),] reacts with P2P4in boiling toluene or xylene to give the hexaligate bimetallic complex [(P2P4)[Cr(CO),>,], whereas [(norbornadiene)Cr(CO),] and P2P4 in benzene at room temperature afford the biligate monometallic derivative [( P, P,)Cr(CO),]. The reactions of o-, rn-, and p-tritolylphosphines (L) with [Cr(CO),] under a variety of conditions of temperature, U.V.irradiation, and molar ratio have been investigated and the products found to be [Cr(CO),L] and trans[Cr(CO),L,]. In addition, with tri(o-toly1)phosphine (L') a complex was obtained which was formulated as [(7c-L1)Cr(CO),] from i.r., 'H n.m.r., and mass spectral data.546 The reactions of the potentially bidentate ditertiary arsine ligand Ph,AsCH, AsPh, (dam) with [Cr(CO),] have been investigated using 'H n.m.r. spectroscopy to determine the mode of co-ordination of the ligand. In [Cr(CO),dam], [Cr(CO),(dam),], and [Cr(CO),(dam),] the ligand is unidentate, but in [Cr(CO),dam] it functions as a normal chelate co-ordinating via both As atoms. The novel complex [Cr(CO),dam] was also obtained which, as reported last year (Vol. 1, p. 73), involves 'octahedral' chromium co-ordinated by two CO groups and one As atom in mutually cis-positions, with a Tc-bonded arene ring occupying the other three sites.547 Complexes [(CO),CrXMe,M(CO),] (X = P or As, and M = Mn or Re) have been prepared by salt elimination from Na,[Cr,(CO),,] and [(CO,MXMe,CIJ An X-ray study of [(CO),Cr(AsMe,)Mn(CO)J has shown that the 543 544

s4s 546 547

P. M. Treichel, W. M. Douglas, and W. K. Dean, Znorg. Chem., 1972, 11, 1615. J. F. Nixon and J. R. Swain, J . C. S . Dalton, 1972, 1038. R. B. King, P. N. Kapoor, and R. N. Kapoor, Inorg. Chem., 1971,10, 1841. J. A. Bowden and R. Colton, Austral. J . Chem., 1971,24, 2471. R. Colton and C. J. Rix, Austral. J . Chern., 1971. 24. 2461.

84


molecules are structurally very similar to the [(CO),CrICr(CO),]- ion."' [(CO)iCr(X'Me,)SnMe,] reacts with Me,X2C1 (X' and X 2 = P or As) to give [(CO),Cr(X'Me,)X2Me2]. which may also be obtained from [(CO),CrX'Me,Cl] and MelX2SnMe,. This product reacts photochemically with [M'(CO),] ( M ' = Cr or W) to form [(CO),Cr(X'Me,)(X2Me,)M'(CO),], the i.r. and ' H n.m.r. spectra of which have been reported. [(CO),CrPMe,PMe,Fe(CO),] has also been prepared and thermolysis of [(CO),CrPMe,PMe, W(CO),] has been shown to afford di-p-(dimethy1phosphino)octacarbonylch romiu m tungsten, [(CO),Cr(PMe, ), W(CO),]. 4 9 'The mass spectrum of [(Me,N), AsCr(CO),] has been reported, together with those of the molybdenum and tungsten analogues: loss of the Me2N fragment was seen to be more prominent than for the corresponding phosphorus compounds.' The unusual fluorocarbon ligand geometry reported last year for [(AsMe,CF,CFHAsMe2)Cr(CO),] and related compounds are incorrect. The X-ray data and chemical properties of the compounds are better interpreted in terms of a disordered arrangement of molecules with normal geometries and dimens i o n ~ The . ~ ~ditertiary ~ arsine chelates ( 5 3 ) have been synthesized by the

R' = SiMe,, SiCl,, F, C1, or CN and R2 = R3 = R4 = H ; or R ' = H and R2 = R 3 = R4 = F (53)

Carius tube reaction of [Cr(CO),] and the appropriate ligand at 140°C for 14 h. The conformational inversion of the five-membered ring has been studied by n.m.r. and some of the complexes have been shown to exhibit marked conformational preferences. 'j Bis(diarylstibino)methanes, ( R2Sb),CH2 (R = Ph or p-tolyl) react with [Cr(CO),] to give the monosubstituted complexes [Cr(CO),(R,Sb),CH,], whereas bis(dimethy1stibino)methane gives [ (Cr(CO),),( Me,Sb),CH,], in which the ligand bridges the t\vo chromium centres."' 548 549 549 550 551

552 553

W. Ehrl and H. Vahrenkamp, Chem. Ber.. 1971.104, 3261. H. Vahrenkarnp. Chem. Ber. 1972,105. 1486. H. Vahrenkarnp and W. Ehrl, Angew. Chem. I n r e m a t . Edn.. 1971,10, 513. R. B. King and T. F. Korenowski, Org. Mass Spectrometry, 1971,5939. W. R. Cullen, I. W. Nowell, P. J. Roberts, J. Trotter.and J. E. H. Ward, J.C.S. Chem. Comm., 1972,

36. W. R. Cullen. L. D. Hall. and J. E. H . Ward, J. Amer. Chem. SOC., 1972,94, 5702. T. Fukumoto, Y. Matsumura. and R. Okawara. J . Organometallic Chem., 1972,37, 113.

The Early Transition ,Metals

85

Si-, Ge-, and Sn-donor Ligands. The synthesis of [H,SiCr(CO),(n-Cp)] has been reported in more detail and the chemical properties of the compound have been described. The Si--Cr bond is cleaved at room temperature by H 2 0 and HCl and at slightly elevated temperatures by Me,NH. At room temperature the primary reaction of Me,NH and Me,N is to form an adduct with the compound.554 The first synthesis of dialkylgermylene- and dialkylstannylene-pentacarbonylchromium complexes has been achieved. Na,[Cr,(CO), "3 in the THF at -78°C reacts with R2MCl, (R = Me, M = Ge; R = Me or Bu', and M = Sn) to form [R,MCr(CO),]. These complexes were isolated by crystallization from hexane solution at - 78 "C as the extremely air-sensitive T H F adducts: the Ge and Sn atoms apparently function as a Lewis acid to T H F and as a Lewis base to chromium. The solution ix. spectra of the complexes are consistent with an approximately C,, structure and are quite similar to those of the analogous carbene complexes. The low v(C--0) stretching frequencies compared with those of other [LCr(CO),] molecules indicate that bivalent germanium and tin are good donor atoms and the positions of the A , relative to the E mode indicate that these new ligands are at least as strong n-acceptors as ~ a r b e n e s . , ~ ~ Carbene Complexes. [(IT-C~)C~(CO),(NO)] reacts with LiPh (1 : 1) to give the (R = Me or Et) to acylmetallate, which may be alkylated with [R,O][BF,] give the diamagnetic carbene complex [(x-C~)C~(CO)(NO)(C(OR)P~)].~ The thiocarbene complexes [(CO),CrC(SR')R2], R' = Me, Et, or Ph, R Z = Me or Ph, have been obtained by the reaction of [(CO),MC(OMe)R2] with HSR' at room temperature. The position of the v(C-0) bands of shortest wavelength, the energy barriers for rotation about the C-S bond, ionization potentials, and dipole moments of the complexes show that the thiocarbene ligands lie between the alkoxycarbene and aminocarbene ligands with respect to ligand-metal-CO charge transfer capability. The crystal structure of [(CO),CrC(SPh)Me] has been determined and the bond lengths have been shown to be consistent with the electron shift within the molecules.557X-Ray studies on [(CO),CrC(OEt)NMe,] have shown that the carbene C-N bond [ 132.8(5)pm] has stronger n-character than the carbene C-0 bond [134.6(5)~m].~~* The 13C n.m.r. spectrum of [(CO),CrC(OMe)R] (R = Me or Ph) indicate that the carbene carbon atoms are extremely deshielded, their signals lying far outside the range of I3C n.m.r. signals of common organic compounds. The strong deshielding compares well with the 'electron deficiency' found from other n.rn.r. measurements on cornplexed carbene atoms.' 14a

554

555

557 558

A. P. Hagen, C. R. Higgins, and P. J. Russo, Inorg. Chem., 1971, 10. 1657. T. J. Marks, J. Amer. Chem. Soc., 1971,93, 7090. E. 0. Fischer and H. J. Beck, Chem. Ber. 1971,104, 3101. E. 0. Fischer, M. Leupold, and C. G. Kreiter, Chem. Ber., 1972,105, 150: R. J. Hoare and 0.S. Mills. J. C. S. Dalton, 1972, 653. G. Hutter and B. Krieg, Chem. Ber., 1972. 105, 67.

86


A full account of the preparation and reactions of acetoxy(2-fury1)carbenepentacarbonylchromium, [(CO),CrC(OAc)C,H,O], has been published.559 [(CO),Cr(OEt)C=CPh] has been prepared by treating [Cr(CO),] with LiC= CPh and Et,OBF, and the molecule has been shown to have a dipole moment of 5.8( 1) D in cyclohexane at 20 sC.560[(Methoxy-4-methyl-l,3-butadienyl)methoxycarbene]pentacarbonylchromium has been synthesized in 0.1 yield by the reaction between [(CO),CrC(OMe)Me] and LiAlH(OBu'), in T H F . Lr., n.m.r., and mass spectra are consistent with the butadienyl fragment having the trans,trans configuration (54).56" ,OMe

H

(CO),Cr -C

\

/

C=C.

H

/

\

/OMe

c=c

[(CO),CrC(OLi)Me] reacts with [(~-Cp),Tic1,] in CH,Cl, at room temperature to give the compounds [(CO),CrC{ 0 T i ( ~ - C p ) , C l ) M e ] and [(CO),CrC(Me)OTi(n-Cp),O(Me)CCr(CO),].'H n.m.r. and i.r. spectra suggest that the electronegativity of the (CO),CrC(Me)O group towards (n-Cp),Ti is approximately equal to that of C1.'22 The reaction of [(CO),CrC(OMe)Ph] with I-aminoethanol gives 5.7 [(CO),CrC(N : CHMe)Ph] and some [(CO)5CrC(NH,)Ph].562 [(CO),CrC(OMe)Me] reacts with saturated o,o-diamines (1 :2) to give amino-bridged diaminocarbene complexes, whereas only mononuclear diaminomonocarbenes could be isolated from the reactions with the aromatic diamines benzidine and 0-to1uidine.j~~ The aminocarbenes [(CO),CrC(NR'RZ)Ph] (R' = H, R2 = H, Me. Et. Ph, or p-MeO.C,H,: R' = R2 = Me; or NR'R2 = pyrrolidene) have been obtained in 50-99 0; yield by treating [(CO),CrC(OMe)Ph] with the corresponding amine R'R'NH. The complexes where R' = H and R2 = Ph or p-MeO.C,H, were separated into cis- and trans-isomers by fractional crystallization and those where R' = H and R 2 = Me or Et were also shown to involve isomers.564 The preparation of a series of ferrocenyl carbene complexes [(CO),CrC(X)C,H,FeC,H,] ( X = 0 - NMe,f, OMe, OEt, NH,, NMe,, or NC,H8) has been reported. The presence of a ferrocenyl group adjacent to the carbene jS9

560

561 562

563 564

J A. Connor and E. M. Jones. J. Cheni. SOC.( A ) , 1971, 3368. E. 0 . Fischer and F R Kreisel, J . Organometallic Chem., 1972,35, C47. L. Knauss and E. 0.Fischer. J . Organometallic Chem.. 1971,31, C71. L. Knauss and E. 0. Fischer, J . Organornetallic Chem., 1971,31, C68. E. 0. Fischer and S. Fontana, J . Organometallic Chem., 1972,40, 367. E 0. Fischer and M . Leupold, Chem. Ber., 1972,105. 599.


87

carbon atom leads to significant differences from other carbene complexes, the ferrocenyl group acting as a good electron donor. These complexes showed some ability to function as specific hydrogenation catalysts.565 The mass spectra of the carbene complexes [(CO),CrC(X)Y] (Y = vinyl or C,H,Z for 2 = 0, S, or NMe and X = OMe, OEt, OAc, OPh,'SEt, SPh, NH,, or NC4Hs) have been reported.566 The new class of carbene complexes, acyloxy-carbenes [(CO),CrC(X)OAc] (X = 2-fury1 or CH,SiMe,) have been isolated. These compounds extend the synthetic range of these carbene systems and afford the nitrile [(CO),CrNCC,H,O] and isonitrile [(CO),CrCNMe], respectively, with HN3.567 The phosphines PR, (R = Et, Pri, Bu, C6H11, or n-C,H,,) react with [(CO),Cr(OMe)Me] in solution at 60 "C to produce [(CO),Cr(PR,)C(OMe)Me], the cis- and trans-isomers of which have been separated by column c h r o m a t ~ g r a p h y .In ~ ~ contrast, ~ dimethylphosphine adds to [(CO),CrC(OMe)Ph] in pentane at -50°C without cleavage of methanol or CO. The pale yellow addition product [(CO),CrC(HPMe,)( OMe)Ph] precipitates and has been characterized by 'H n.m.r. and mass spectra. This phosphorus ylide complex appears to be significant as a model compound for the primary step in the aminolysis of 'alkoxycarbene complexes.5 6 9 Arene Carbony1 Complexes. The protonation of [( 1,3,5-Me,C6H,)Cr(CO)3] and [(XC,H,)Cr(CO),] (X = H, Me, or Ac) at the metal by a (1 : 1) mixture of CF,CO,H and BF,,H,O has been established by 'H n.m.r. spectroscopy. No protonation occurs in neat CF,CO,H; however, substitution of C O by a PPh, group results in an increase in the basicity of these complexes and facilitates protonation by the acid either pure or dilated in CH2C12.570[{(nCp)Cr(CO),),Hg] reacts with tetraethylthiuram disulphide, Et,NC(S)S - S(S)CNEt,, ( 1 : l ) on refluxing in benzene to give the new chromium-mercurybonded dithiocarbamate complex [(n-Cp)(C0)3CrHg(S,CNEt2)].s71 The first example of a 1,3-dienetetracarbonylchrornium complex, butadienetetracarbonylchromium, has been prepared by condensing chromium atoms with butadiene and subsequent treatment with CO. The compound has been characterized by mass, ix., and 'H n.m.r. spectral The reactions of 5-acetyl-1,2,3,4,5-pentamethylcyclopentadiene with metal carbonyls provide a convenient route to various pentamethylcyclopentadienyl metal carbonyl derivatives. Thus, [Cr(CO),] and Me,C,Ac give [(Me,C,CrThe crystal structure of (CO),},] in boiling 2,2,5-trimethylhe~ane.'~~ 565 566

567 568 569 5 70

571 572

J. A. Connor and J. P. Lloyd, J . C. S. Dalton, 1972, 1470. J. A. Connor and E. M. Jones, J . Organometallic Chem., 1971,31, 389. J. A. Connor and E. M. Jones, Chem. Comm., 1971,570. E. 0. Fischer, H. Fischer, and H. Werner, Angew. Chem. Internat. Edn., 1972,11,644. F. R. Keissel, C . G. Kreiter, and E. 0.Fischer. Angew. Chem. Internat. E d n . 1972.11.643. B. V. Lokshin, V. I. Zdanovich, N. K. Baranetskaya, and V. N. Setkina, J. Organometallic Chem., 1972,37,331; D. N. Kursanov,V. N. Setkina, P. V. Petrovskii, V. I. Zdanovich, N. K. Baranetskaya, and 1. D. Rubin, ibid., 1972,37, 339. W. K. Glass and T. Shiels, Inorg. Nuclear Chem. Letters, 1972,8, 257. R. B. King and A. Efraty, J . Amer. Chem. SOC., 1972,94, 3773.

88


[(N-methylpyrrole)Cr(CO),] has been determined. The three Cr-CO bonds in the molecule are mutually orthogonal and the five ring atoms are approximately co-planar; however, the carbon of the methyl group is bent out of the Some fourteen complexes ring plane by some 9” away from the [LCr(CO),] (where L is thiophen or a substituted thiophen) have been prepared from [(MeCN),Cr(CO),] and the appropriate thiophen. Electrondonor substituents (e.g. Br or OMe) inhibit the formation of the complex and the larger yields are generally obtained with alkyl-substituted t h i ~ p h e n s . ’ ~ ~ The polarographic behaviour, i.r. and U.V.spectra. and other properties of some substituted thiophen chromium tricarbonyl complexes have been deterThe crystal structures of (3a,4-8,8a-~)-[5.7,8-trimethyl-8~-cyclohepta-(~)thiophenl- and (1-3,3a.8a-~)-[5,7-dimethyl-4H-cyclohepta-(~)-thiophen]chromium tricarbonyl complexes, (55) and (56). respectively, have been determined.s 7 6 Me

Me

Ph,Hg reacts with [ c r ( c o ) , ] in a boiling diglyme-octane mixture to yield bis(triphenyltricarbonylchromium)mercury, [{(CO),Cr(C,H,)),Hg]. This compound reacts with HgCl, and iodine to give [(C0)3CrC,H,HgCl] and [(CO),CrC,H,I]. respectively.”- Isomeric [(L)Cr(CO),] complexes (L = 1,2-, 1,3-, or 1,4-dimethylbenzene, 1,2,3-, 1,2,4-, or 1,3,5-trimethylbenzene, or 1,2,3,4-, 1,2,3,5-, or 1,2,4,5-tetramethylbenzene)have been separated by gas c h r ~ m a t o g r a p h y .ortho-Substituted ~~~ isopropylbenzene chromium tricarbony1 complexes show diastereotopic non-equivalence of the gem-dimethyl groups and partial resolution of the OMe-substituted complex has been achieved.579 1.r. and Raman spectra of solutions of [(Ar)Cr(CO),] complexes (Ar = C,H,, PhF, PhMe, O-Me,C,H,, or 1,2,3-Me,C,H3) have been recorded and those for [(PhMe)Cr(CO),] assigned in detail. These spectra indicate that 573 574

G . Huttner and 0. S. Mills. Chem. Ber.. 1972.105, 301. C. Sezard. R Roques. and C . Pnmmier. Cnmpt. rend.. 1971.272. C. 2179.

’” R . Ciuilal-d and P. Fournari, Compt. rend. 1971, 273, C, 160.

57h

577

5’8 579

Y . Dusausoy, R. Guilard. J. Protas, and J . Tirouflet, Compr. rtwd.. 1971,272, C, 2134; Y. Dusausoy. R. Guilard, and J. Protas. ibid.. 1971,273, C, 228. G. A. Razuvaev, G. G. Petukhov, A. N. Artemov, and N. I. Sirotkin, J. Organometallic Chem., 1971, 37, 313. J. S . Keller, H. Veening, and B. R. Willeford, Analvt. Chem., 1971,43, 1516. G. Barbieri and F. Taddei. Org. Jfagn. Resonance, 1971, 3, 503.


89

the local symmetry approximation is of restricted validity when discussing C-0 stretching vibrations.580Tricarbonylchromium complexes of cc,b,y,ciitetraphenylporphin and its metal chelates with Cr", Mn"', Ni", Cu", and Zn" have been prepared. The complexes vary in stability, the Zn" complex being the most stable. The i.r. spectra of the complexes give no evidence for any appreciable interaction between the two metals, and it is suggested that this is due to the absence of n-interactions between the porphin and the phenyl ring systems.58 The crystal structure of tricarbonyl-(2,4,6-triphenylphosphorin)chromium (57) has been reported. The Cr(CO), group has a central position above the Ph

phosphorin ring; this and the long Cr-P distance (248 pm) suggest that the compound is a typical [(n-arene)Cr(CO),] complex.582 have The crystal and molecular structures of [(he~aethylborazine)Cr(CO)~] been determined. The three-fold axis of the Cr(CO), group is perpendicular to the borazine ring with the ring nitrogens staggered with respect to the CO groups. The different Cr-B and Cr-N bond lengths, 231 and 222pm, respectively, give the borazine skeleton a mild-chair conformation. One B-N bond of length 136 pm differs substantially from the mean of 144 pm.583 The first synthesis of a phosphazene complex has been reported. Hexachlorocyclotriphosphazene reacts with [(MeCN),Cr(CO),] to give [(PNCl,),Cr(CO),] as a bright yellow, readily sublimable, crystalline solid in 20% yield., 8 4 Bis-n-arene Complexes.-The first ring-exchange reactions involving metallocenes have shown that chromocene is quite labile with respect to exchange with both [Li(C,D,)] and [ N ~ ( K - C , D , ) , ] . ~Molecular ~~ core binding energies for [Cr(i~-Cp),] indicate a small positive charge on the ring and suggest that Cp is a better donor and a weaker acceptor ligand than C 0 . 5 0 5 The heat of formation of [Cr(C,H,),] has been estimated as - 146 k 8 kJ mol-' and those of [Cr(C,H,),X] (X = c1, Br, or I) as -4, -71, and - 113 8 kJ mol- I , respectively.585 The thermal stability of bis(n-ary1)580

581

582

583 584

585

G. Davidson and E. M. Riley, Spectrochim. Acta, 1971,27A, 1649. N. J. Gogan and Z . U. Siddiqui, Canad. J . Chem., 1972,50, 720. H. Vahrenkamp and H. Noth, Chem. Ber., 1972,105, 1148. G. Huttner and B. Krieg, Angew. Chem. Internat. Ed., 1971, 10, 512. N. K. Hota and R. 0. Harris, J.C.S. Chem. Comm., 1972,407. V. I. Tel'noi, I. B. Rainbovich, B. G. Gribov, A. S. Pashinkin, B. A. Salumatin, and V. I. Chernova, Zhur. f;z. Khim., 1972,46, 802.

90


chromium complexes has been shown to increase with alkyl substitution as [Cr(C6H6),] < [Cr(EtPh),] < [Cr(O-Et2C6H,)2].586D.t.a. studies have suggested that [Cr(EtPh),] reacts with [Cu(acac),] ria a [Cr(EtPh),acac] intermediate to form [Cr(acac),], EtPh, and C U . ~ ”X-Ray diffraction data (C,,H4N, = 7,7,8,8-tetrahave been reported for [Cr(C6H,),]+C,,H4N, cyanoquinodimethane). the inter-ring distance within the cation being 321 pm.588 E.s.r. studies on bis(x-arene)chromium(i) complexes, in particular [Cr(biphenyl),] have been reported. The observed proton hyperfine splitting could not be explained either by configuration interaction over the n-system, or by a direct Cr-H i n t e r a ~ t i o n . ~ ~ ’ The crystal structure of the chromium metallocarborane salt Cs[Cr(B,C,H,Me,),] has been determined. The anion consists of two icosahedra sharing a chromium atom as a common vertex.590 Dinitrogen, Nitrosyl, and Isocyanide Complexes.-The i. r. spectrum of chromium atoms condensed with excess dinitrogen at low temperatures shows evidence for only CrN, formation. This behaviour contrasts markedly with the range of species observed in similar experiments with CO (p. 77). It is suggested that the reluctance of metals to co-ordinate to several N, molecules is due to the large positive charge created on the metal atom on bonding to N,, as TCacceptance appears to be more important, relative to o-donation, in N, than in CO complexes. Prolonged photolysis of the matrix causes changes in the i.r. spectrum, the behaviour being consistent with dinitrogen bonded to a chromium metal cluster, the positive charge now shared by more than one metal atom.59’ Photolysis of [Cr(CO),] in N, or N,-Ar matrices at 2 0 K appears to produce [Cr(CO),N,].507b The results of LCAO MO calculat i o n ~ for ~ ~this , molecule suggest that the molecule involves less back-bonding than [Cr(CO),], in contrast to the above conclusions. [Cr(NO)((SiMe,),),] has been shown to have a pseudo-tetrahedral C,,, structure (58) with a linear Cr-N--0 system. These Cr--N(O) and N-0 0 I

N

I

(Me,Si),N

A \ N(SiMe,),

Cr-N(0) = 173.8(2.0) pm N-0 = 119.1(2.8) pm Cr-N(S>) = 179.0(1 .O) pm (Si)N-Cr-N(Si) = 99.0(5)0

N (SiMe3)2 (58) s86

N. N. Travkin, V. P. Rumyantseva, and B. G. Gribov. Zhur. obshchei Khim., 1971,41, 1916. A. Razuvaev. G. A. Domrachev. and L. G. Abakumova. I x e s t . Akad. Nauk S.S.S.R., Ser. khim., 1971, 2082. R . P. Shibaeva, A. E. Shvets, and L. 0. Atovmyan, Doklady Aka&. Nauk S.S.S.R., 1971, 199, 334. W. Karthe and W. Kleinwachter, Z . phys. Chem. (Leipzig), 1971, 247, 241. D. St. Clair, A. Zalkin, and D. H. Templeton, Inorg. Chem., 1971,10, 2587. J . K . Burdett. M. A. Graham, and J. J. Turner, J . C . S. Dalton, 1972, 1620. W. J. Chambers and N. J. Fitzpatrick, Proc. Roy. Irish Acad. ( B ) 1971.71,97.

” -G. 588

489 590 s91

592


91

bond lengths suggest that NO is acting as a n-acceptor ligand and the Cr-N(Si) bond lengths suggest a considerable n-interaction over these The reaction of [Cr(H2O),N0l2 with edta has been studied polarographically and spectrophotometrically and the reaction product identified as [Cr(edta)NO]. This product may also be obtained from [Cr"(edta)H,O] and NO, NO;, or NO,, suggesting that this species is able to react uia an inner-sphere mechanism in its redox reactions.593 E.s.r. spectra have been used to show aquo-substitution in [(H,O),Cr(NO)S,CEt]+ by P(OR), (R = Me, Et, Pr", Pr', or Bu), (EtO),PPh, P(SEt),, or EtP(SEt),, and g-values for the liquid and frozen solutions have been reported.594 The nitrogen 1s binding energies in the nitrosyl complexes trans-[CrCl(NO)(diars),]ClO,, [ (n-Cp)Cr(NO),],, and K,[Cr(CN),NO] have been reported.595 A normal-co-ordinate analysis of the [Cr(CN),NO] 3 - ion has been completed which indicates that the force constant of the N--0 bond has decreased drastically in the series [Fe(CN),NO]' - , [Mn(CN), NO], -, [Cr( CN),N0I3 - , consistent with the greatest metal-NO back-bonding occurring for chromium.596The electronic configuration and transitions of the ground and excited states of [Cr(CN),N0I3- and [Cr(NH3),N0l2+ have been described using MO calculations to interpret the data obtained from low-temperature spectral studies.597 [Cr(CN),N0I3- in DMSO solution in the presence of alkyl halides reacts to form [Cr(CN), -,(DMSO),]"-3 complexes (n = 1-5), each of which exhibits a characteristic e.s.r. The one-electron oxidation of [Cr(CN),N0I3- has been shown to have a half-peak potential at + 0.823 V us. S.C.E.5991.r. spectra recorded for y-irradiated [Cr(CN),N0I3in alkali-metal host lattices suggest the formation of species resembling [Cr(CN),NOI4- and [Cr(CN),N0I5-, although no confirmation could be obtained from e.s.r. studies.600 [(H2O),CrCNI2+ reacts with Hg" to form [(H20),CrNCHg14+ having A,, of 535(27.8) and 395(20.1) nm.60t A new series of isonitrile complexes has been prepared, [(CO),-,Cr(CNR),], where x = 1-3 and R = Me, Et, Pri, But, C,H, Ph, p-MeC6H4, or p-C1C6H,. [(CO),Cr(CNR)] and [ (CO),Cr(CNR),] may be obtained by treating Et,N[Cr(CO),I] with an excess of R N C in CH,Cl, solution in an atmosphere of CO at room temperature. [ (CO),Cr(CNR),] is obtained from [ (cycloheptatriene)Cr(CO),]. On the basis of spectral results it was concluded that in these compounds there is no firm evidence for any n-acceptor behaviour by the isonitriles. All of these +

D. I. Bustin and J. Mocak, 'Proceedings of the 3rd Co-ordination Chemistry Conference', ed. J. Gazo, Slovak Tech. Univ., Bratislava, 1971, p. 39. N. S. Garif'yanov A. D. Troitskaya, A. I. Razumov, P. A. Gurevich, and 0. I. Kondrat'eva. Zhur. neorg. Khim., 1971,16, 1059. 5 9 5 P. Finn and W. L. Jolly, Inorg. Chem., 1972,11, 893. 5 9 6 G. Paliani and A. Poletti, Spectroscopy Letters, 1972, 5, 105. 5 9 7 P. T. Manoharan and P. Ganguli, Chem. Phys. Letters, 1971,11, 281. 5 9 8 D. C. McCain, Inorg. Chim. Acta, 1971,5, 611. 5 9 9 J. Mocak and D. I. Bustin, ref. 593, p. 227. 6oo M. B. D. Bloom, J. B. Raynor, K. D. J. Root, and M. C. R. Symons, J . Chem. SOC.(A), 1971,3212. 6 0 1 J. H. Espenson and W. R. Bushey, Inorg. Chem., 1971 10,2457. 593

594

92

Inorganic Chemistrv of the Transition Elements

complexes undergo a one-electron oxidation in CH,Cl,, the oxidation being accompanied by a chemical reaction.602The ease of oxidation of the hexakisarylisonitrile complexes varies in the order Cr[ (CNC,H,OMe),] > A One-eleCtrOn [Cr(CNc6H4Me)6] > [Cr(CNPh),] 'u [Cr(CNC,H,Cl),]. oxidation of each compound has been observed, the potentials being reasonably accessible chemically.603 Binary Systems.-Halides. The heats of formation of CrF, and CrF, have been evaluated as -655 and -958 kJ mol-', respectively, from e.m.f. measurem e n t ~ . ~ ~ ~ CrCl, molecules have been isolated in solid inert-gas matrices and their i.r. spectrum has been recorded 33-1000 cm- The isotopic shifts and i.r. selection ' ~ d-d spectrum of gaseous CrCl, has rules indicate a linear ( & 10') s t r ~ c t u r e .The been discussed in terms of ligand field theory.237The heat capacity of anhydrous CrCI, in the temperature interval 2-20K has been determined605 and the sublimation and decomposition pressures of the compound have been recorded.6O 6 O.uide.5, Sulphides, anti Tellurides. C r 2 0 , and CrB, react at 1000°C to give CrB and Cr30, the latter having the cubic structure of the P-tungsten type.423 Single crystals of CrO, with a rutile structure have been grown from a KOH flux at 900°C and 36 kbar. X-Ray studies have shown that these crystals involve axially compressed CrO, octahedra, with four equatorial bonds of length 191 pm and t w o axial bonds oflength 189 pm.607The introduction ofa hydrogen atom into this structure to form CrO(0H) causes little change: thus the interconversion between the two compounds is easily achieved.608Strong evidence for the formation of gaseous Cr0,OH has been obtained in studies of the highA new temperature reaction of Cr,O, with H 2 0 in the presence of 02.609 experimental technique has been described whereby soft X-ray Cr-L,[,,Cr-K, and 0 - K emission and absorption spectra are combined and used to construct a complete M O diagram for simple Cr-0 species, e.g. C r 2 0 3 ,CrO,, CrO:-, and Cr,O:-. The results obtained for Cr,O, suggest that the three outermost electrons have t,, symmetry and are involved in two distinct bonding mechanisms, one of these electrons being in a metal-metal covalent bond and the other two being associated with the Cr-0 Ic-bonds. These results6'' do not support the narrow d-band model which has been proposed for transitionmetal oxides. Finely powdered C r 2 0 3 at 900--1300"C reacts with a stream of H,Se to '02

603 '04 '05

'06 '07

'OR '09

J. A. Connor, E. M. Jones, G . K. McEwan, M. K. Lloyd, and J. A. McCleverty, J . C. S. Dalton, 1972, 1246. P. M. Treichel and G . E. Dirreen, J . Orgaltometallic Chem., 1972,39, C20. H. Tanaka, A. Yamaguchi, and J. Moriyama, Nippon Kinzoku Gakkaishi, 1971,35, 1161. M. 0.Kostryukova.and L. V. Luk'yanova, Zhur. eksp. teor. Fiz., 1971,61, 732. R . Matsuzaki, H. Morita, and Y. Saeki, K o g y o Kagaku Zasshi, 1971,74, 1592. P. Porta, M . Marezio, J. P. Remeika, and P. D. Dernier, Mater. Res. Bull. 1972,7, 157. M. A. Alario Franco and L S . W. Singh, J . Therm. Analysis, 1972,4,47. Y.-W. Kim, Diss. Abs. (B), 1970,31, 1311. D. W. Fischer, J . Phys. and Chem. Solids, 1971,32,2455.


93

give CrSe, (n = 1.24-1.22j.246 The magnetic structure of CrTe has been studied between 77 and 370 K.61 Nitrides, Phosphides, and Arsenides. The phase diagram for the Cr-N system between 900 and 1350°C has been constructed612 and thermodynamic relationships in this system have been calculated. These latter studies indicated the extreme sensitivity of the kinetics of Cr-N reactions to oxygen impurity.613 CrP, has been synthesized by reaction of the elements at pressures of 1565 kbar. The crystal structure involves chromium atoms co-ordinated by six phosphorus atoms in a distorted octahedral arrangement with Cr-P = 232-239 pm.614CrMAs (where M = Co or Nij have been characterized by X-ray diffraction spectra.61 Silicides and Gerrnanides. E.m.f. measurements have afforded the AH" and AS"1023 values for CrSi as -29.9 kJ mol-' and 1.17 J mol-' K-l, and for CrSi, as -26.0 kJ mol-' and 1.63 J mol-I K-', respectively.616 The compounds Cr,Ge, Cr,Ge3, and Cr,Ge, have been identified in the Cr-Ge system at high chromium content.617 Borides. The new compound TmCrB, has been prepared and shown to be isostructural with YCrB,.618 The conditions for preparing the metallic compound Cr,BC, from the elements have been investigated.619 Chromium(11) Complexes.-The oxidation of chromium(1r) in alkaline solution has been studied polarographically and the reaction shown to be irreversible with E , = - 1.65 V us. S.C.E. In the presence of nitrilotriacetic acid, salicylate, ethylenediamine, and edta the E , values were determined as - 1.075, - 1.33, - 1.38, and - 1.48 V, respectively.620 The production of [Cr(edtajNO] from [Cr"(edta)H,O] and NO, NO,, or NO; suggests that this complex is able to react via an inner-sphere mechanism in its redox reactions.593 MCrF, (M = K, Rb, or NH,) have been isolated from aqueous media and shown to have tetragonal unit cells and to be paramagnetic with antiferromagnetism at very low temperatures.621 Sr2Cr"Cr1**F12and related nonstoicheiometric phases with calcium and barium have been isolated and iden tified.62 2 Ta,Cr06 has been prepared by heating Ta,O,-Cr,O,-Cr mixtures at

'11

'I3 614

'15 616

'17

''* 'I9

''O 621

"*

0. 0. Galkin, E. A. Zavads'kii, and B. Ya. Sinel'nikov, Dopovidi Akad. Nauk. Ukrain. R.S.R., Ser. A , 1971,33, 837. T. Mills, J . Less-Common Metals, 1972,26, 223. T. Mills, Austral. Aeronaut. Res. Lab. Met. Note, 1970, ARLjMet. 84. W. Jeitschko and P. C. Donohue, Acta Cryst., 1972, B28, 1893. A. Nylund, A. Roger, J. P. Senateur, and R. Fruchart, J . Solid State Chem., 1972.4. 115. V. N . Eremenko, G. M. Lukashenko, and V. R. Sidorko, Zhur. f i z . Khim., 1971,45, 1996. B. Rawal and K. P. Gupta, J . Less-Common Metals, 1972,27, 65. Yu. B. Zuz'ma and S. I. Svarichevskaya, Dopovidi Akad. Nauk Ukrain. R.S.R., Ser. A, 1972,34,166. V. S. Neshpor, N. V. Vekshina,V. P. Nikitin, and L. Ya. Markovskii, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1971,7, 2170. E. Fischerova and L. Grandeova, Scr. Fac. Sci. Natur. Univ. Purkyninae. Brun., 1971,1,51. A. DeKozak, Rev. Chim. minerale, 1971,8, 301. D. Dumora, J. Ravez, and P. Hagenmuller, Bull. SOC.chim. France, 1971, 2010.

94


850-1050 T and shown to have a deformed trirutile-type structure.623 1:1 Complexes of chromium(rr) with isonicotinic ( K = 2.33 x lo3) and ferron6,' have been characterized. New chromium(I1)complexes with ethylenedithiodiacetic acid (H2Z)and diethylenetrithiodiacetic acid (H,T) have been reported. CrSO, reacts with Na,Z to give the red compound CrZ,2.5H20 which, if left in contact with the mother liquor, gives a blue isomeric species. Magnetic studies have shown that this blue form ( p = 4.87 BM) behaves as a simple paramagnetic species, whereas the red form (p = 2.76 BM) exhibits antiferromagnetism. It is suggested that the latter involves a chromous acetatetype structure with non-co-ordinated sulphur and a direct Cr-Cr bond. A similar structure also appears likely for CrT,3H20, prepared from CrSO, and Na,T, since this is also red and antiferromagnetic, with p = 2.05 BM at room temperature.626 Antiferromagnetic interact ions have also been identified in [Cr(S CNEt 2)2] and the two new related compounds [Cr(S,CNMe,),] and [Cr(S,CNC,H8)2].627The electronic absorption spectra of Cr" ions doped in CdTe have been reported.33 The new chromium(r1)complexes of 1,2-diaminopropane (pn), [Cr(pn),]X,,nH,O ( X = C1. Br. or I and n = 2, 1, or 0. respectively), 1,3-diaminopropane (dmp), [Cr(dmp)X,], N N (dap), [Cr(dap),X,], 1,2-diamino-2-methylpropane dimethylethylenediamine (NNdmn), [Cr(NNdmn)Br,] and [Cr(NNdmn)I,], and NN'-dimethylethylenediamine (NN'dmn), [Cr(NN'dmn)Cl,], have been prepared by the reaction of the appropriate metal halide and amine in ethanol under rigorously anhydrous conditions. No bis(amine) complexes of pn or tris(amine) complexes of other amines could be isolated. All these complexes are high spin with p 2- 4.8 BM. The reflectance spectra of the pn complexes suggest that they have distorted octahedral structures. The [Cr(amine),X,] complexes appear to have trans-octahedral structures with co-ordinated anions, whereas [Cr(amine)X,] seem to be halogen-bridged polymers.628 Chromium(I1rj Complexes.--Halogeno-comple.ues. The crystal structure of (N,H,),[crF,] has been reported and the average Cr-F bond length in the octahedral anions determined as 190.5 pm.629MNi[CrF,] (M = K or Rb) and KNi[CrF,],H,O each contain a network of M2F6 octahedra with Cr-F = 193 + 2 pm.630MnCrF,631and the x- and p-modifications of Li3[MF6]48 have been prepared from melt reactions and characterized in X-ray studies. Sr,Cr"Cr"'F,, and related non-stoicheiometric calcium and barium species have been reported.622Fifteen new double fluorides have been obtained from

,

623 624

625

626

"' 629 630 631

P. Massard, J. C Bernier. and A. Michel, Ann. Chim. (France) 1971,6,41. N. Calu and G. Agrigoraei, Anal. Sti., C'niv. "A1 1. Cuza" lasi, Sect. Ic, 1971, 17, 139. P. Lingaiah and E. V. Sundaram. J . Indian Chem. Soc., 1971,48,961. J. Podlaha and J. Podlahova, Inorg. Chim. Acta, 1971, 5, 413, 420. L. F. Larkworthy and R. R. Patel, Inorg. Nuclear Chem. Lett, 1972,8, 139. L. F. Larkworthy, K. C. Patel, and J. K. Trigg, J . Chem. SOC.(A), 1971, 2766. B. Kojik-Prodid, S. QavniEar, R. Liminga, and M. SljukiC, Acta Cryst., 1972, B28, 2028. D. Babel, Z . anorg. Chem.. 1972,387, 161. G. Ferey, M. Leblanc, C. Jacoboni, and R. Depape, Compt. rend., 1971,273, C , 700.

The Early Transition kletals

95

the systems CrF,-MF, (M = Li, Na, Rb, Cs, or TI) and CsF,-M'F, (M' = Pb, Mn, or Cd) and six new triple fluorides formed by reaction between M,[CrF,] and M:[CrF,],.621 The preparation of solid phases in the K/Na-Cr"'-F-H,O system has been discussed and Na3[CrF6], K2,Na[CrF,], K,[CrF,],aq, and K,[CrF,(H,O)] have been identified by their X-ray diffraction spectra. Similar studies led to the preparation and characterization of (NH,), [CrF6] and (NH,), [CrF,( H, O)] .6 Powder reflectance spectra have shown that PCI,,CrCI, involves an octahedral CrC1, c h r ~ m o p h o r e .The ~ ~ ~preparation, unit cells, and vibrational ( M = Cr, spectra of the hexa-ammine rnetal(II1) salts [M(NH,),][CrCl,] Co, or Rh) have been reported.634

0-Donor Ligands. The interaction of nitrous oxide with a-chromia at room temperature has been studied by i.r. spectroscopy and two surface complexes have been identified. Each complex is characterized by a pair of bands, at 2305 and 1339, and 2238 and 1237 cm-l, corresponding to the N,O antisymmetric and symmetric stretches. The former pair are exhibited by molecules which are the more easily removed and which may be bonded as Cr t N-=N+=O, with the molecules exhibiting the latter pair of absorptions bonded as Cr t O - - N + , N . 6 3 5 Reviews of the properties of the chromite spinels FeCr204,636aMnCr,O,, and have been published. The electrochemical reduction of K,CrO, in a molten LiCl-KCI eutectic is shifted to more positive potentials by the addition of CoC1, or ZnCl,. In the case of the latter an insoluble reduction product LiZn,CrO, is obtained.,,' Other studies on oxide compounds containing chromium(II1)are summarized in Table 7. The preparation of a 1 : 1 Cr"'-PuO,+ complex has been achieved by the oxidadation of Put" by Cr20;-, the resulting green complex being purified on an ionexchange column.638 The aqueous chemistry of chromium(rri) above 100 "C has been investigated with particular reference to corrosion phenomena and the possibility of hydrothermal synthesis of chromite in serpentine Isotopic exchange studies have indicated that the CrO, unit exchanges intact between [Cr(H,0),I3 and [C~MO,O,,H,]~-. This appears to be the first established exchange of such a [Cr(H,0)s(EtOH)]3' has a stability constant of 6.5 x lo-, and is only stable in perchlorate solutions with > 80 "/, EtOH.,,' +

E. Baumgartel, J. Teich, and W. Muller, 2. anorg. Chem., 1971, 383, 113: E. Baumgartel and J. Teich, ibid., 1971, 386, 279, 285. 6 3 3 J. H. J. Dawson and D. W. Smith, Inorg. Nuclear Chem. Letters, 1971,7, 81 1. 6 3 4 H. H. Eysel, Z . anorg. Chem., 1972,390, 210. 6 3 5 E. Borello, L. Cerruti, G. Ghiotti, and E. Guglielminotti, Inorg. Chim. Acta, 1972,6,45. 6 3 6 ( a ) G. C. Ulmer, 'High Temperature Oxides', ed. A. M. Alper, Academic, New York, 1970, vol. 1, p. 251; ( b ) T. Funabashi and K. Shiratori, Kotai Butsuri, 1971,6, 519. 6 3 7 K. W. Hanck and H. A. Laitinen, J . Electrochem. Soc., 1971,118, 1123. 638 T. W. Newton and M. J. Burkhart, Inorg. Chem., 1971,10,2323. 639 T. W. Swaddle, J. H. Lipton, G. Guastalla, and P. Bayliss, Canad. J . Chem., 1971, 49, 2433. 640 K.-H. Lee, Diss.Abs. (B), 1971,31,5240. 641 V. I. Chibiskova, Ya. Yu. Makarov-Zemlyanskii, and N . N. Pavlov, Nauchn. Trudy Mosk. teknol. Inst. degk. Prom., 1971, 125. 63i

96


Table 3

Mixed-oxide compounds containing chromium (111) Compound

Comments and reported properties

LiCrO,

e

MgCr204

origins of structural distortions discussed Cr"' in octahedral sites with Cr-0 = 193-206 pm e.d., X i.r., m.p. i i . , m.p., X

Ba,Cr,-xO,, (.u 2 0.5)

,

BiCrO LiCr(MoO,), Li,Cr( MOO,),

Re&

a

Mx(Lio,5x~ro.s*W 1 -X Q 3 - 3xF3x (M = Li, Na. K, Rb, C s ; x = 0.054.7)X, tungsten-bronze phases i.r., X gives Cr"' in a D, site with Cr,UO, Cr-0 = 197 pm X, perovskite structure Ba,CrUO,

h C

d e

f 9 h

( a ) C. Simo and S. L. Holt. J . Solid Srate Chem., 1972, 4, 76. ( b ) N. W. Grimes, J. Phys. (C), 1971, 4, L342. ( c )D. M. Evans and L. Katz, Arra C r y s f . . 1972. B28, 1219. (d)Yu. Ya. Tomashpol'skii and Yu. N.Venevtsev. Kristallograj7ya. 1971.16,1037.(e)V. L. Butukhanov, E. J. Get'man, and M. V. Mokhosoev, Zhur. neorg. Khim.. 1972,17, 1169; V. K. Turnov and V. A. Efremov, ibid., 1971,16.2026;V. K. Trunov and Yu. A. Velikodnyi, l x e s t . Akad. Nauk neorg. Material?., 1972, 8, 881. ( f )A. Vedrine, J.-P. Besse, and M. Capestan, J . Inorg. Nuclear Chem.. 1972, 34, 2771. (g) H . R. Hoekstra and S. Siegel, J. Inorg. Nuclear Chem., 1971,33.2867. ( h )J. C . G e n e t , P. Poix, and A. Michel, Ann. Chim. (France),1971,16,83.

Chromium metal reactswith brominein D M F solutiontoafford [Cr(DMF),](Br3)3which has been characterized by magnetic and spectral studies.'03 The compound Cr,(S0,),,12CO(NH,),,6H20has been identified in the ureachromium sulphate-water ternary system at 25 0C,642and the greater thermal stability of urea complexes of chromium(m) over aquo-complexes has been described and The dinuclear chromium(~rr)sulphamato-

H20\

v /\

'

H,NO,SO-Cr-OH-

H,O

,0S02NH2 Cr-

\o/

OH,

'0SO2NH,

H

complex (59) has been synthesized.644 Ligand field absorption and emission spectra of chromium tris(OO'-sulphinates), [Cr(O,SR),] (R = Me, Ph, or p-MeC,H,), have been reported and the ligands shown to be approximately equivalent to DMSO in the spectrochemical series. In emission spectra the 642 643 644

A. A. Karnaukhov and V. A. Tatarinov. Ref. Zhur. khim., 1970, 15B769.

N. N. Runov and V. P. Zakharova, Uchen. Zapiski Yaroslav. Gos. pedagog. Inst., 1970, no. 78,103. I. I. Kalinichenko and K. A. Kotyaeva. Trudy Ural. politekh. Insf., 1970, no. 190, 84.


97

complexes exhibit a broad-band fluorescence at ca. 11200 cm-', the first examples of this type of luminescence for oxygen-co-ordinated c h r o m i u m ( ~ ~ ~ ) . ~ ~ ~ CrSi, reacts with H3PO4 to form C I - ( H , P O ~ )The . ~ ~ complex [Cr(H,O),(03PH2)12 has been prepared by heating a deoxygenated aqueous solution of [Cr(H,O),](ClO,), and H,PO, at 45 "C for 6-8 days, the product being separated using an ion-exchange column. The electronic spectrum of the complex has been recorded [A,,, = 596 (1 5.4),419 (16.8), and 267 (5.5 cm2mol- ') nm (figures in parentheses are molar absorptivities)] and deprotonation and 1 : 1, 1 :2, and 1 :3 chromium(1rr) complexes aquation have been of nonamethylimidodiphosphoramide,(Me,N),P(O)NMeP(O)(NMe,),, have been prepared. Electronic and i.r. spectral studies indicate that the ligand coordinates via the two oxygen atoms.646 Inorganic co-polymers [Cr(H,O)(OX'R'R20)(OX2R3R40)], (X', X2 = P or As, R1-R4 = Me, Ph, or CsH17) of high thermal stability have been prepared by treating CrC1,,6H20, or Cr(NO,),, H,O, with the corresponding phosphinates a-arsinates in T H F in the presence of K2C03.647The reaction of diethyl chlorophosphate, (EtO),P(O)Cl, with anhydrous CrCl, at elevated temperatures leads to dechlorination of the phosphate and the precipitation .of polynuclear Cr[OP(OEt),],.42 A number of chromium(II1)polyphosphate glasses have been prepared and investigated as ion exchangers and shown to be adequately stable and selective for the alkali-metal ions.648 A review has been published which describes the i.r. spectra and thermogravimetric properties of chromium(n1) acetate complexes.649 Absorption spectra of a solution of iron(n1) and chromium(Ii1) perchlorates in acetic acid solution reveal bands at 520 and 450 nm which have been attributed to a heteronuclear complex containing two (or one) iron and one (or two) chromium atoms per molecule.650 The polarized electronic spectrum of basic chromium(II1) acetate, [ C r , 0 ( C H , C 0 , ) , ( H , 0 ) 6 ] ~ ~ y 6 H 2 ~has , been measured over the temperature range 3 0 0 4 . 2 K. The exchange coupling between the three chromium atoms was observed in the 750-690 nm region where transitions originating from different ground-state spin levels were identified.65' Trihydroxyglutaric acid forms a 1: 1 complex with chromium(r~r) which has a stability constant of 0.9 x lo5. In the presence of copper(r1) a mixed complex is formed and dark bluish-green crystals of Na,[CuCrC,,H,0,,],5H20 have been isolated.652 The substituted benzoic acid complexes (60) have been prepared by heating a mixture of CrC1,,6H20 and RC,H,CO,H in Pr'OH.653The +

645

646

647 648 649 650

"' 652 653

H

L. S. Brown and J. N. Cooper, Znorg. Chern., 1972. 11, 1154. M. W. G. De Bolster and W. L. Groneveld, Rec. Trau. chim., 1972,91,95. P.L. Nannelli and H. D. Gillman, Ger. Offen. 2110664, (Cl,C.O8g), 1971. D. Beteridge and F. Snape, J . Znorg. Nuclear Chem., 1971,33, 3557. T. Golgotiu and I. Rosca, Bull. Znst. Politekh., Zasi, 1970,16, 117. B. P. Nikol'skii, V. V. Pal'chevskii, A. A. Pendin, Kh. M. Yakulov, E. Ya. Offengenden, and E. Ya. Kalontarova, Doklady Akad. Nauk S.S.S.R., 1971,200, 128. L. Dubicki and P. Day, Znorg. Chem., 1972,11, 1869. E. G. Chikryzova and E. E. Topaly, Zhur. neorg. Khim., 1971,16, 1341. W. J. Pangonis, U.S. P. 3579555, (C1.260-438.5;C07f, C23c), 1971.

98


chemical and other properties of chromium(III)-aspartate and -asparaghe complexes have been reported.654 [(H,0)5Cr(0,CCHRSH)]2+and [(H,O),Cr(O,CCHRS)]+ (R = H or Me) have been prepared by treating chromium(II1) with mercaptoacetic or 2mercaptoproprionic acid for 3 h at 60-C. Both complexes are hydrolysed by

O0-Cr

-0/ \

\

co\ -Cr Cl2/ O H

(60) R

=

SO,NH, or MeCONH

acids and both react with iodine to give dimers of the form [(H,O),Cr(02CCHRSSCHRC0,)Cr(H,0)514+.655 The grey-blue compounds CrZ(OH),2H20(where H ? Z = ethylenedithiodiacetic acid or diethylenetrithiodiacetic acid) have been characterized.626 Partial resolution of [Cr(acac),] into optical isomers has been achieved on a column of D( +)-sorbit01 or D( +)-mannit01 followed by elution with benzenestudy of the ligand reactivity at the 3-position in l i g r ~ i n A. ~comparative ~~ [Cr(acac),] and [Co(acac),] has been attempted using nitration and VilsmeierHaack reactions. The cobalt(n1) complex was found to be more reactive in both reactions and this difference has been rationalized on the basis of the electron density in the (Macac)ring as estimated by Hiickel calculations.657The deuteron and proton n.m.r. linewidths of [Cr(acac),] and some other paramagnetic acac complexes have been recorded. The significantly better resolution achieved for the deuteron spectra suggests that useful information should be obtainedfrom . ~ ~ films of [Cr(acac),] have been such studies of paramagnetic c ~ m p l e x e sThin shown to be p-type semiconductor^.^^^ Several metal complexes containing acetylacetone as a neutral ligand have been prepared: for example [Cr(acac),] reacts with dry HBr in CH,CI, containing free acetylacetone to give [Cr(acac)(Hacac)Br,]. and [CrCI ,(THF),] reacts with acetylacetone evolving HC1 and forming [ C r ( a c a c ) ( H a ~ a c ) C 1 ~ ] . ~ ~ ~ The mass spectra of several partially fluorinated P-diketonatochromium(iI1) complexes have been determined and discussed.660 Hydroxyhexafluoroisobutyric acid, HOC(CF,),CO,H (34), acts as a bidentate ligand and forms a tris-octahedral complex with chromium(m).286 A new ligand, hydroxymethylenenorcamphor (61) (HL) has been synthesized and CrL, has been prepared and characterized.66' L. J. Anghileri, J . Nuclear B i d . Med., 1971, 15, 98. E. Cotte, H. Diaz, A. Miralles, and E. L. Bertha, Acra Cient. Venez., 1971,22, 93. 6 5 6 V. G . Markovic and G . K. Schweitzer, J . Inorg. Nuclear Chem., 1971,33, 3197. 6 5 7 T. Schirado, E. Gennari, R. Merello, A. Decinti, and S. Bunel, J . Inorg. Nuclear Chem.. 1971, 33, 341 7. 6 5 9 A. P. Chappe and J . I. Vargus, Phys. Stat. Solidi ( A ) , 1972,10, 543. 6 5 9 Y. Nakamura, K. Isobe, H. Morita, S. Yamazaki, and S. Kawaguchi, Inorg. Chem., 1972,11,1573. "' A. L. Clobes, M. L. Morris, and R. D. Koob, Org. Mass Spectrometry, 1971, 5, 633. 6 6 1 L. L. Borer and R. L. Lintvedt, Inorg. Chem., 1 9 7 2 , l l . 2113. 654

655


99

Chromium(II1)has been shown to complex with arsenazo(1)at the hydroxygroups on the naphthalene nucleus.662 S and Se-Donor Ligands. The potentially terdentate ligand thiodiethanol, S(CH,CH,OH),, forms navy-blue [Cr{S(CH2CH,0H),}Cl,] on refluxing

with CrC1,,6H20 in ethanol. The compound was characterized by magnetic ( P = 3.45 BM) and electronic spectroscopic (625,481,275, and 240 nm) studies.

A comparison of the properties of the compound with those of related complexes suggests that the environment about the metal is probably the trigonal-bipyramidal one favoured by the ligand geometry.498 When a suspension of CrC1, in excess triethylthiophosphate is heated at 150-200 “C the trisdiethylthiophosphato-complex precipitates. A polynuclear, cross-linked structure has been suggested for this complex although there is no evidence for any appreciable magnetic exchange across the Cr-(0-P-S)-Cr bridges.266The tris(P-thiohas ketonato)chromium(III) complex of 4-phenyl4-mercaptobut-3-en-2-onate been prepared and ~haracterized.~” The crystal structure of LiCrS, has been shown to resemble that of NiAs with ordering of lithium and chromium ions in alternate layers. The magnetic structure of the compound, which shows a spin ordering at 4.2 K, was also determined in this study.268The series of compounds MCr,X, (M = Sr, Ba, Pb, Fe, or Eu, and X = S or Se) has been synthesized and their structures and magnetic and electrical properties described.663 The far-i.r. spectra of the semiconducting spinels CdCr2X4(X = S or Se) have been reported664and the metal-deficient sulpho-spinels Cr8/9M10/901,3S4(where M = A1 or In) prepared.665Single crystals of ScCrS, have been obtained by chemical transport reactions and the unit cell has been shown to be related to that of NaCl with 5 occupancy of the cation sites.666 The new family of compounds LnCrSe, (Ln = La, Ce, Pr, or Nd) has been prepared by heating Cr,Se, and Ln,Se, 662

663

664 665 666

I. N. Lozanovskaya, V. A. Lyutsedarskii, and E. P. Kaplina, Trudy Novocherkassk. politekh. Inst., 1969, no. 220, 67. W. Lugscheider, H. Pink, K. Weber, and W. Zinn, Z: angew. Phys., 1971, 32, 80; F. Okamoto, K. Miyatani, K. Minematsu, H. S. Yasuo, and K. Yoshida, ‘Proceedings of the International Conference on Ferrites’, 1970, p. 616; K. Adachi, K. Sato, and K. Kojima, Mem. Fac. Eng., Nagoya Unio., 1970, 22, 253. T. Arai, K. Wakamura, and K. Kudo, J . Phys. SOC.Jap., 1971,30, 1762. F. K. Lotgering and G . H. A. M. Van der Steen, J . Solid State Chem., 1971,3, 574. J. P. Dismukes and R. T. Smith, Z . Krits., 1970,132,272.


100

U ~ C U Ofor 24 h. Their magnetic properties have been interpreted on structures involving edge-sharing, irregular CrSe, octahedra, separated by LnSe, polyhedra.667 X-Ray studies have shown that tris(0-ethyl xanthato)chromium(m) has ca. octahedral co-ordination about the metal with an average Cr-S bond length of 239.3 pm. The dimensions of the ligands suggest that the bonding descrip-

(1: 1) at 1000 ' C in

+

tion ( S-)ZC=OR makes an important contribution to their electronic structure.668 K,Cr,O- reacts with morpholine-4-carbodithioate (41) (mdtc) in aqueous solution at pH 4 to give the [Cr(mdtc),] complex.320As part of a general survey of the co-ordinating properties of multidentate ligands the chromium(IIi)complexes of the dithiocarbazate anions [Cr(R1R2NNR3CS2),] (R1 = R 2 = R 3 = H or Me, R ' = H and R 2 = R 3 = Me, or R' = R2 = Me or Ph. and R 3 = H) have been prepared. Their electronic and i.r. spectra suggest that [Cr(NH2NHCS2),] and [Cr(NH,NMeCS,),] involve bidentate S N co-ordination of each ligand. Substitution on the terminal nitrogen, however, prevents its co-ordination and other complexes appear to possess S S - ~ h e l a t e s P ~ ~ A series of chromium(rrr) complexes with substituted dithiophosphinic acids has been isolated. [Cr(S2PR1RZ),](R' = R2 = Me, Et, Pr, Pr', Bu", But, or C,H, or R' = Ph, R 2 = But) have been prepared from CrC13,6H,0 and R'R2P(S)SH or its sodium salt. The corresponding complexes with R' = F or CF, may be obtained by adding an excess of the anhydrous acid to anhydrous CrC1, and subsequently removing HCI and the excess acid. All the complexes are dark-blue solids and their electronic spectra and magnetic moments have been determined. Their volatility, together with their solubility in non-polar solvents. suggestc that they are monomeric. Preliminary crystal-structure data for [Cr(S2PMe2),] confirm this .ind show that the molecules have a trigonally The electronic distorted octahedral structure with Cr-S = 243 spectrum and magnetic behaviour of the tris(dithiocacodylato)chromium(m) complex, [Cr(S,AsMe,),], have been interpreted in terms of an octahedral CrS, arrangement.671 The thio- and seleno-phosphinato-complexes of chromium(rrr), [Cr{ Se(S)PR,),] (R = Et or Ph) and [Cr(Se(Se)PEt,},], have been prepared by treating anhydrous or hydrated CrCI, with the corresponding NaSe(X)PR, salt, and characterized by their electronic and i.r. spectra.672 N-Donor Ligands. The full account of the preparation and properties of [Cr(N(SiMe,),},] has been published.36

669 ''O

6'2

H. D. Nguyen. J. Etienne, and P Laruelle. Bull. SOC. chim. France, 1971, 2433; 0. Gorochov, E Barthelemy, and H. D. Nguyen. Cornpt. rend., 1971,273, C , 368. S. Merlin0 and E. Sartori, Acto Cryst., 1972, BU), 972. C. Battistoni, G. Mattongno, A. Monaci. and F. Tarli, Inorg. Nuclear Chem. Letters, 1971,7,1081. R. G. Cavell, W. Byers, and E. D. Day. Inorg. Chem., 1971.10,2710:W. Kuchen and A. Rohrbeck, Chem. Ber., 1972.105, 132. A. T. Casey, D. J Mackey, and R. L. Martin, Austral. J . Chem., 1971,24, 1587. H. Hertel and W. Kuchen, Chem. Ber.. 1971,104,1735: P. Christophlienk, K. V. V. Rao, I. Tossidis, and A. Miiller, ibid., 1972. 105, 1736.


101

Ligand-substitution reactions of chromium(1rr) ammines ha\ e been discussed.673 The crystal structures of [Cr(NH,),][CuBr,] and [Cr(NH,),][CuBr,Cl,] have been determked and the cations shown to have crystallo= 89.6(2)0 and Cr-N = 205.9(6) pm!74 graphic 3 symmetry with N-Cr-N In the salts [Cr(NH,),][MF,] (M = Mn or Fe) the Cr-N bond lengths are 206.7(3) and 207.3(2) pm, re~pectively.,~~ Irradiation of an aqueous solution of [Cr(NH3),N3l2+at pH 1 in the ligand to metal charge-transfer region leads to redox decomposition with quantum yields of0.45 at 3 13 nm and 0.4 at 263 nm, whereas irradiation at longer wavelengths leads to photoaquation forming .5 O0 [Cr( NH3)4(H,O)N,] Equilibrium studies have that the first formation constant of the chromium(IIIbethy1enediamine system is < over 104-foldsmaller than the value (lo',.,) previously reported. [Cr(en),-,(tn),] (x = 0-3 and tn = trimethylenediamine) complexes have been prepared and resolved using nitro( + )D-camphor. These mixed complexes have the same absolute configuration, A, as the 'pure' [Cr(en),13 and [Cr(tn),13+ species.677Selective intervention of an optically active counterion in the relaxation processes of excited enantiomeric complexes can lead to partial resolution. This has been achieved for [Cr(phen),]+ using tartrate.,'^ In the series of [Cr(bipy),]"+ complexes (n = 3 4 ) the Cr-N stretching frequencies are approximately constant. This unexpected result has been taken to indicate that the strength of these Cr-N bonds does not change over this wide range of oxidation states, the ligand to metal a-donation decreasing but the metal to ligand n-back-bonding increasing as the oxidation state is lowered. Also, it is suggested that the electron density around the metal is similar throughout the series and that for such compounds the use of formal oxidation states is misleading.679 The new chromium(II1)isocyanato-complex (Ph,As),[Cr(NCO),] has been prepared and itsix. and electron spectra are consistent with N-bonded ligands6*' A mixture of K,[Cr(NCS),] and rn-xylidine (m-xyl)at 100 "C for 4-5 h gives (rn-xyl)[Cr(NCS),(m-xyl),] as purple crystals. Salts with other cations have also been isolated, and p-xylidine forms the analogous derivatives.68 H[Cr(NCS),(BzH)],EtOH, [Cr(NCS),(MeBz)J [Cr(NCS),(MeBzH),] ,8H20, and H[Cr(NCS),(MeBzH),],2H20 (BzH = benzimidazole and MeBzH = 2methylbenzimidazole) have been prepared by refluxing K, [Cr(NCS),] with the appropriate ligand, in alcohol for the former two complexes and in water for the latter.682 +

+

'

673 674

675

676

677 678 679

681

682

E. L. Simmons and W. W. Wendlandt, Co-ord. Chem. Rev., 1971,7, 11. S. A. Goldfield and K. N. Raymond, lnorg Chem., 1971,10, 2604. K. Weighardt and J. Weiss, Acta Cryst., 1972, B28, 529. J. Bjerrum and 0. Moensted, Bull. Chem. SOC.Japan, 1971,44, 3492. M. Rancke-Madsen and F. Woldbye, ref. 593, p. 273. L. A. P. Kane-Maguire, B. Dunlop, and C. H. Langford, J . Amer. Chem. SOC., 1971,93,6293. J. Takemoto, B. Hutchinson, and K Nakamoto, Chem. Comm., 1971,1007. R. A. Bailey and T. W. Michelson, J . Inorg. Nuclear Chem., 1972,34, 2935. 1. Ganescu, A. Popescu, and M. Proteasa, Coll. Czech. Chem. Comm., 1971,36, 3088. S. P. Gosh and A. Mishra, J . lnorg. Nuclear Chem., 1971,33,4199.

102


P-Donor Ligands. A series of chromium(Ir1) compounds involving diphos has been prepared and characterized by spectral studies. Analyses suggest the unusual composition Crz(diphos),X,,nH,O ( X = C1, Br, 1. or NCS and n = 0. 2. or 4).683 Cornplrxes inrolciny n Varietj. of Donor Ligands. Magnetically pure crystals of p-oxo-bis{penta-&mminechromium(I1I))halides. [(NH,),CrOCr(NH,),]X4,H20, have been obtained for the first time by carrying out their synthesis rapidly at - 1 2 to - 5 "C in the absence ofdaylight. X-Ray studies on the chloride and bromide complexes have shown that the Cr-0-Cr system is linear. The temperature dependence of the paramagnetic susceptibility can be fitted accurately to a simple exchange model, whereas samples prepared in a conventional manner show irreproducible magnetic behaviour due to the impurity [( NH ,),CrOHCr( NH 3)40 H]X,.6 " [Cr(N H J5 (OP(OEt), 1.3 may be conveniently prepared from [Cr(NH,),N,]'+ and NOClO, in (EtO),PO. This complex appears to be useful for the preparation of other [Cr(NH,),L]"+ complexes, where L is a weak ligand.685 [Cr(NH3),(02CH:CHC02H)]2+ [&,,, = 490 (56.6) and 364 (38.1 cm2 mol-') nm] has been prepared by the addition of a slight excess of maleic anhydride to a solution of [Cr(NH,),(H20)](C104),in D M F in the presence of PhNMe,.686 The complex trans[Cr(NH 3),C12]CI,H,0 has been prepared and characterized, and isomerization to the cis-isomer has been shown to occur in the solid state at 200 "C with The green trans-dichloro-trans-diaquoan enthalpy change of 5 kJ moltrans-diamminochromium(III) salt [Cr(NH,),( H,0),C12]C1 [llmax 420 (23.9) and 606 (30.3 cm2 mol-') nm] has been isolated and its aquation to trans[Cr(NH,)2(H20)3C1]2+and trans-[Cr(NH, j2(H20j4] studied.688 Molecules of CrC1,,2Me3N are five-co-ordinated with a basically trigonalbipyramidal geometry. The average bond lengths are Cr-C1 = 223.8 (5) and Cr-N = 215 pm: two CI--%r-Cl angles are 124.3 ( I ) > and the other is 111.4 (2)".The distortion from idealized symmetry may be attributed to electronic effects since in D,, symmetry there will be one electron in an e'MO.' The heats and entropies of formation of the sulphato-complexes [Cr(en),(S0,),]3-2" ( n = 1-3) have been reported and the complex with n = 1 has been shown to be the most stable.689The reaction ofcis- and trans-[Cr(en),Br,]' with DMSO affords mainly ~is-[Cr(en),Br(DMS0)]~+ and cis-[Cr(en),( D M S 0 ) J 3 +, which have been isolated, as have the thermodynamically less stable corresponding r r a n s - c ~ r n p l e x e s .The ~ ~ ~stoicheiometry and rate of aquation of trans-[Cr(en),F,]' have been determined and the sole pro+

683 684 685

686 687 688 689

690

P. B. Lutz, Dim. Abs. ( B ) , 1971, 31, 6481. E. Pederson, Acta Chem. Scand., 1972,26, 333. E. A. Hosegood and J. L. Burmeister, Synth. Inorg. Metal-org. Chem., 1971,1, 21. R. Davies and R. B. Jordan, Inorg. Chem., 1971,10, 2432. K. Nagase and N. Tanaka, Bull. Chem. Soc. Japan, 1972,45. 1097. C. M . Couldwell, D . A. Pickering, and D. A. House, J . Inorg. Nuclear Chem., 1971, 33, 3455. V. E. Mironov, G. K. Ragulin, I. E. Umanova, Yu. B. Solov'ev, V. P. Mikhailova, and P. T. Dong, Zhur. f i z . Khim., 1972,46, 257. D. A. Palmer and D. W. Katts, Inorg. Chim. Acta, 1972.6, 197.


103

duct has been shown to be [Cr(en)(enH)(H2O)F,I2', which is a unidentate en complex in which the two fluorides are probably mutually trans. This complex was isolated in solution by ion-exchange chromatography and characterized by its electronic spectrum. [Amax = 519 (40),410sh (ll), and 366 (18.6) nm]. Further aquation leads to [Cr(en),(H,O)FI2+ [A, = 512 (47.3) and 378 (29.4cm2 mol-l)nm] and [Cr(en)(H20),F,]2+ [Amax = 542(37),410(10.1),and 371 (12.5 cm2 mol-') trans-[Cr(en),Cl,]Cl has been shown to isomerize to the cis-isomer irreversibly at 250-290°C.692 Synthetic routes to the new azidobis(ethy1enediamine) complexes trans-[Cr(en),( N3)X]C10, (X = Cl, Br, or N3) and cis- and trans-[Cr(en),(H20)N,1Zf have been The new propylenediamine (pn) complexes cis-[Cr(pn),X,]X (X = C1 or Br) and ~is-[Cr(pn),Br(H,O)]~ have been ~ h a r a c t e r i z e d .The ~ ~ ~stepwise 'unwrapping'of the tetraethylenepentamine(tetren)ligand from [Cr(tetren)H,0I3 to give [Cr(H,0),I3 has been investigated spectrophotometrically and chromatographically in 0.1-4M-HCI0,. The d-d absorption spectra of all the intermediates [Cr(tetren)(H20)J3+ (n = 1-5) were obtained.695 Cation-exchange cellulose has been shown to provide a general method for the resolution of optical isomers of cis-M"'bis( 1,lO-phenanthroline) complexes, e.g. cis-[Cr(phen)2C1,]Cl,3H20.696 [CrCI,L,] (L = 2-, 3-, or 4-cyanopyridine) complexes have been prepared by mixing hot (ca. SOOC) butanol solutions of CrC13,6H,0 and the cyanopyridine (1: 10) and allowing precipitation in the dark. The 3- and 4-cyanopyridine complexes are non-electrolytes in DMF, but the 2-cyanopyridine species behaves as a 1: 1 electrolyte, probably because of hydrolysis to [CrCl,L2(H20),]Cl,H,0.697 The series of phen and bipy complexes [Cr(phen),X,]Cl,aq (X = C1, or C,O,), [Cr(phen),( H,O),](NO,),,2 H 2 0 , [Cr(bipy),C12]C1,2H,0, [Cr(bipy),C1,]C1,HC1,2H20, and [Cr(bipy),OH(H,O)](ClO,), have been characterized by their X-ray powder diffraction patterns. They are isomorphous with the corresponding Co, Rh, Ir, and 0s"' compounds and have the cis-configurat i ~ n *. ~cis- [Cr(bipy), C1(H, O)] [Amax = 517 (43.5 cm2 mol-') nm] has been isolated by cation-exchange chromatography from aged solutions of cis-[Cr( bipy),C12]C1,,2H,0. Further aquation affords a pink complex [Amax = 528 (29.5 cmz mol- ') nm], which is believed to be the previously unreported [Cr(bipy)(H,0),I3+ species.699 [Cr(py)(H20),]3+ [Amax = 560 (18.2) and 260 (3460 cm2 mol-') nm] has been prepared'"" by the stepwise aquation of [Cr(py),(H20),l3+. The chromium(m) complexes of tetraphenylporphin (tpp), [Cr(tpp)OH] and [Cr(tpp)OR],2ROH +

+

+

+

"* 693 694

695

696 697

698 '0°

S. C. Pyke and R. G. Linck, Inorg. Chem., 1971,10,2445. C. Sat0 and S. Hatakeyama, Bull. Chem. SOC.Japan, 1972,45,646. J. E. Smith, Diss. Abs. (B), 1970,31,2549. J. A. McClean, jun. and N. A. Maes, Inorg. Nuclear Chem. Letters, 1972,8, 147. S. J. Ranney and C. S. Garner, Inorg. Chem., 1971,10, 2437. J. A. Broomhead and W. Grumley, Inorg. Chern., 1971, 10, 2002. J. C. Chang, M. A. Haile, and G. R . Keith, J . Inorg. Nuclear Chem, 1972, 34, 360 P. Anderson and J. Josephsen. A c t a Chem. Scand., 1971,253255. S . Y. J. Ng and C. S. Garner, Inorg. Chim. Acta, 1971, 5, 365. A. Bakac and M. Orhanovic, Inorg. Chem., 1971,10,2443.

104

Inorganic Chemistrjr of the Transition Elements

(R = Me or Et), have been reported”’ and the series of substituted tetrazole complexes [Cr(L),0H],nH20 (L = 5-o-Cl- C,H,* CN4,5-p-R C,H,- CN,, where R = H, C1, or OMe, or 5-p-C1 C,H,. CH,CN,) has been prepared by treating NaL with an aqueous solution of c h r o m i u m ( ~ r ~ ) . ~ * ~ Triethanolamine complexes of chromium(m)have been reported and characterized in i.r. spectra and thermal-decomposition studies.703The chromium(II1) nitrilotriacetato-complex [CrL(H,(I),] [L = N(CH,CO,); ] complexes with thallium(m) to give [ [CrL,(OH)(H,0)],T1]3- with a formation constant of 9 +_ 3 x lo’, at 25 cC.7040 The hydrolysis and dimerization of [CrL(OH),I2in alkaline media have been investigated and K2[LCr(OH),CrL],4H,0 has been isolated. This complex behaves as a dibasic acid forming [LCr(OH)CrLI3- and is [LCr(O),CrLI4- : in strongly alkaline solutions [Cr,L,(OH)J2obtained.’ 04b The 1 :3 chromium(I1Ikbiuret (NH,CONHCONH,) complex has been = 600 and 425 nm) and shown to have stepwise stability conidentified (jwmax stants K , = 1800. K z = 550, and K , = 76.705 Several chromium(il1) complexes with naturally occurring =r-amino-acids have been prepared. [Cr(A),],2 H 2 0 (HA = r-amino-n-butyric acid, I-glutamine, or I-leucine), which appear to involve the p-form unlike the corresponding cobalt(rrr) complexes. [Cr(llysine),(H,O),]C1,3H,0, and [Cr(OH)(A’),(H,O)],H,O (HA’ = a-amino-nbutyric acid, I-valine, I-leucine, or I-glutamine) have all been characterized by their i.r. and electronic s p e ~ t r a . ” ~Several chromium(II1) complexes with DL-r-phenylalanine-NN-diacetic acid (H,A) have been prepared including [Cr(A)(phen)],H,O, K[Cr(A)(OH)H20],5H20, and K, [Cr(A)(C, 0,)],2H20, in which the ligand is q ~ a d r i d e n t a t e . ~The ” stability constants of the N N ’ ethylenediaminedisuccinic and NN-ethylenediaminebis-u-glutaric acid complexes of chromiurn(i1r)have been determined as 11.08 and 11.88, respectively, at 30 3C.‘08 Na[Cr(cydta)],4H20 (where H,cydta = trans-1,2-cyclohexanediaminetetra-acetic acid) has been prepared and its i.r. and electronic spectra [A,, = 548 (215) and 394 (103 cm2 mol-’) nm] suggest that cydta acts as a sexidentate ligand.”’ An aqueous solution of KCr(SO,), reacts with the hydroxamic acids RCONHOH (R = Ph, Bz, o-HO - C6H4, pC1- C,H,, p-anisyl, p-NO, C6H4, or cyclohexyl) to give [Cr(ONHOCR),] which have been characterized by magnetic and spectroscopic ~ t u d i e s . ~ ’The ’ mass spectrum of [Cr(oxine),]

-

702

’04

’O’ ’08

’09

’”

E. B. Fleischer and T. S. Srivastava, Inorg. Chim. Acta, 1971. 5. 151. P. Labine and C. H. Brubacker. jun., J . Inorg. Nuclear Chem., 1971,33, 3383. G. N. Rao and S. C. Rustagi, Indian J. Chem., 1971,9, 1390. ( a ) F. Ya. Kul’ba and Yu. A. Makashev. Zhur. neorg. Khim., 1971, 16, 1917; ( b ) A. Ricard and P. Souchay, Rec. Chim. minc;rale, 1971,8, 859. M. B. Mishra and R. M. Sanyal, Technology, 1971,8, 34. H. Mizuochi, A. Uehara, E. Kyuno, and R. Tsuchiya. Bull. Chem. SOC. Japan, 1971,44, 1555. A. Uehara, E. Kyuno. and R. Tsuchiya, Bull. Chem. SOC.Japan, 1971,44, 1548. S. G. Tak. 0. P. Sunar. and C . P. Trivedi, Zndian J. Chem., 1971.9, 1394. N. Tanaka, K. Kanno. T. Tomita, and A. Yamada, Inorg. Nuclear Chem. Letters, 1971, 7, 953. B. Chatterjee, J . Indian Chem. SOC.1971, 48.929.


105

(Hoxine = 8-hydroxyquinoline) involves the ions [Cr(oxine),]+ ( n = 0-3).71 ' The diastereoisomers of the complexes tris[N-(R or S)-cr-benzylethyl-5-nitrosalicylaldiminato]chromium(~~~) (62), involving optically active ligands, have

been synthesized and separated by thin-layer chromatography. Two isomers were identified for both the R- and S-ligands and, although no attempt was made to assign absolute configurations for these four isomers, they appear to be the same as those of the analogous cobalt(u1) corn pound^.^'^ [Cr(CO),] reacts with the 2-acylpyrroles RCOC,H,NH (R = H, Me, or Ph) in refluxing n-octane to give tris(2-acylpyrrolato)chromium(111) complexes (63) as dark-yellow or red crystalline solids. 2-Aminophenol-4-arsonic acid and K,Cr,O, react to form the analogous dark-red complex (64).714The complexes of 8-amino-7-hydroxy-4-methylcoumarin (HL) (65), [Cr(L)Cl,(H,O),] and (HL)[Cr(L),(OH)(H,O)], have been characterized7 * and the existence of

Me

"' 712

'13

'I4 715

J. Charalambous, M. J. Frazer, R. K. Lee, A. H. Qureshi, and F. B. Taylor, Org. Mass Spectrometry, 1971, 5, 1169. J. E. Gray and G. W. Everett, jun., Inorg. Chem., 1971,10, 2087. C. S. Davies and N. J. Gogan, J . Inorg. Nuclear Chem., 1972,342791. K. H. Surborg and H. J. Roth, Pharm. Z., 1971,116, 1958. D. K. Rastogi, A. K. Srivastava, P. C. Jain, and B. R. Agarwal, Inorg. Chirn. Acta, 1972,6, 145: D. h.Rastogi and P. C. Jain, Indian J . Chem., 1972,10, 100.

106


isomeric species for bis-o,o'-dihydroxya2oaryl chromium chelates has been l 6 The stability constant of the 1: 1 demonstrated chr~matographically.~ chromium(II1)-riboflavine complex has been determined7I7 as 2 x Dimethoxyethane(L) forms a 1 : l adduct with CrCI, which is a dimeric [CrCl,L], species containing two chloride bridges." The complexes cis[Cr(C204)2(NCS)(H,0)]2-[&,,, = 558 (75.8) and 412 (89.0 cm2 mol-') nm] [A,,, = 585 (61.5) and 415 (74.1 cm2 mol-') and C~S-[C~(C,O,),(NCS)(OH)]~The novel complex [Cr(H,O),nm] have been prepared for kinetic (NCS)(SCN)]+. containing one N-bonded and one S-bonded thiocyanatogroup, has been prepared in aqueous solution by the ieaction of [Fe(NCS)( H 2 0 ) 5 ] 2 +with [Cr(H20),IZ+ in the presence of free NCS-. This complex undergoes two spontaneous reactions, aquation and linkage isomerism, both of which involve the S-bonded ligand.499 1.r. evidence has been presented for a bridging thiocyanato-group in the dinuclear complexes [(NH,),CrSCNCr(NCS),] and [(NH,),CoSCNCr(NCS),] prepared by the reaction of [Cr(NCS),13- with the appropriate [M(NH,),(H20)]3+ complex.719

The Schiff base sr-N-methyl-S-methyl-P-N-(2-pyridy1)methylenedithiocarbazate (L) (66) behaves as a neutral terdentate ligand and [Cr(L)Cl,] has been isolated from reaction of the ligand and CrC1,,6H20 in ethanol.720Pyruvic acid thio- and seleno-semicarbazones (H,L) complex with chromium(m), to form species such as [Cr(L,)]- and [Cr(L)(HL)].721 The single missing cis-isomer of [Cr(CN),(H,O),] has been prepared by the reaction of cis-[Cr(CN),(H,O),] with CN- at O"C, and the very unstable trans-isomers of [Cr(CN),(H,O),] - and [Cr(CN),(H,O),] were also obtained at 0 "C by treating [Cr(CN),(H,O),] with KCN.',, Organometallic Complexes.The range of chromium(II1)0-bonded carbon derivatives has been extended this year. Treatment ofCr(OBu'), with RMgX (R = Me, Et, Ph, or mesityl) affords CrR, via the corresponding CrR, Tris(2,2,3-trimethylbicyclo[2,2,l]hept-l-yl)chromium (67) has been obtained H . Pfitzner, Angew. Chem. Internat. Edn.. 1972, 11, 312. R . Nayan and A. K. Dey, Indian J. Chem., 1972,10, 109. 'I8 K. R. Ashley and S. Kulprathinpanja, Inorg. Chem., 1972,11, 445. '19 R . C. Buckley and J. G. Wardeska, Inorg. Chem., 1972.11, 1723. 7 2 0 M. A. Ah, S. E. Livingstone, and D. J. Phillips, Inorg. Chim. A c t a , 1972, 6, 1 1 . "I N. Ya. Negryatse, A. V. Ablov, and N. V. Gerbeleu. Zhur. neorg. Khim., 1972, 17, 124: G. F. Volodina, G. A. Kiosse. N. V. Gerbeleu, and A. V. Ablov, Doklady Akad. Nauk S.S.S.R., 1971, 200. 1349. '*'G. D. Jimerson, Diss. Abs. ( B ) , 1971,31. 7166. '16


107

by reaction ofthelithiumalkyl with CrC1,,3THF inpentane. [Cr(CH,SiMe,),] has been prepared by the reduction of Cr(CH,SiMe,),. Its electronic spectrum [ , I , , ,= 1281 (50)and615(760cm2mol-1)nm],magneticmoment(p= 3.7 BM), and e.s.r. spectrum suggest that it is one of the few known examples of tetrahedral c h r o r n i u m ( ~ ~The ~ ) .chromium ~~~ atom in Na,[CrPh5],3Et20,THF has been shown to be five-co-ordinate with C20m i c r o ~ y m m e t r y . ~ ~ ~

The characterization of [Cr(H,0),Mel2+ has been confirmed and its electronic spectrum shown fo have absorption maxima at 550 (9.6), 392 (196), and 258 (2160 cm2 mol- ') nm.724The rate of formation of [Cr(H,O),LI2+, where L is an alkyl or aryl radical, has been shown to be dependent on the probability of locating an uhpaired electron on the donor carbon and on the nature of its The series of monoalkyl complexes [RCrCl,(THF),] (R = Me, Et, Pr, or Bu') have been prepared by treating [CrCl,(THF),] with AIR, or AlR,(OEt) in THF. The thermal stability of these air-sensitive, green complexes decreases with increasing length of the alkyl chain, and the pure complexes' catalysis of ethylene polymerization, at room temperature and reduced pressure, varies as Me > Et > B U ' . ~ The , ~ air-stable 2- and 3-pyridylmethyl(ethylenediamine)chromium(III)complexes [2(or 3)-NC, H,MeCr(en), H,O] have been obtained by the reaction of the corresponding picolyl chlorides with [Cr(en),(H,0),]2 . 7 z Chromium(1v) Complexes.-These are restricted to the tetrahedral CrR, elimination-stabilized alkyl compounds. A full account of the preparation and properties of [Cr(CH,SiMe,),] has been published. The compound is remarkably unreactive towards chemical reagentsotherthan oxygen., [Cr(CH,CR,),] (R, = Me,, Ph,, or PhMe,) have been prepared using the lithium or Grignard derivatives of R,CCH,Cl. The compounds are intensely maroon-purple coloured crystalline solids readily soluble in organic solvents with magnetic moments of ca. 2.7 BM.4 Tetrakis-( 1-norbornyl)- and tetrakis-(2,3,3-trimethylbicyclo[2,2,l]hept-l-yl)-chromium complexes have been prepared by the reaction of CrC1,,3THF with the corresponding alkyl lithium in pentane ~ o l u t i o n . ~ -+

+

,

723 724 725

726

727

K. Schmiedekrecht, E. Mtiller, J. Krausse, W. Reichardt, and B. Elsner, ref. 593, p. 301. M. Ardon, K. Woolmington, and A. Pernick, fnorg. Chem., 1971,10, 2812. H. Cohen and D. Meyerstein, J.C.S. Chem. Comm., 1972,320. K. Nishimura, H. Kuribayashi, A. Yamamoto, and S. Ikeda, J . Organornetallic Chem., 1972,37, 317. C. T. LOO,L.-Y. Goh, and S. H. Goh, J.C.S. Dalton, 1972, 585.

108

Inorganic Chemistry of rhe Transition Elements

Chromium(v) Complexes.-CrF,, which has been shown to have a monomeric v a p o ~ r reacts , ~ ~ ~with excess XeF, at 60°C to give XeF, and non-volatile XeCr2F,,. At 120°C CrF, fluorinates both Xe and XeF,, forming XeF, and XeF,, respectively, and CrF3.728The n.q.r. spectrum of Cs[CrOCl,] has been 35 reported and covalency in this and other d' systems discu~sed.~ The vibrational spectrum of [ C r O J - has been reported for the first time72" Na,CrO, and the unit cell parameters of Ca,[CrO,] ,have been has been prepared by heating Na203,Cr203,and Na,CrO, under argon for 15h at 350 "C and then 15h at 500 "C and the compound characterized by X-ray powder diffraction and magnetic ~ t u d i e s29b . ~ Co-ordination reactions of chromium(v) have been studied by recording e.s.r. spectra of solutions of Na,CrO, in dioxan containing ligands such as acac, tiron, carboxylic acids, and en. Bidentate oxygen ligands exhibit the strongest tendency to complex with chromium(v) under these conditions.730Bischelate complexes of chromium(v) involving hydroxo-ligands, e.g. salicylic, sulphosalicylic, and thiosalicylic acid, pyrocatechol and its derivatives, and 2,3-dihydroxynaphthalene, have been prepared by the reaction of the ligands with DMF, acetone, or MeCN solutions of K,Cr207 or (NH4)2Cr,07,and their e.s.r. characteristics have been determined.731 Potassiumperchromate, K,[CrO,]. has been shown by spectral measurements to release 0, molecules in the excited singlet state. This compound provides a convenient source of singlet oxygen which can be liberated at a controlled rate.501The results of ab initio MO calculations on the ground state of [Cr0,I3 suggest that the bulk of the Cr-0 bonding arises from the overlap of the metal's atomic orbitals with the 0-0 in-plane n-bonding and Jr*-anti-bonding densities (cf: the Chatt-Dewar bonding scheme). The 0-0 bond length of 141(4) pm in the anion indicates that the latter overlap is dominant.732 Chromium(vi ) Complexes.-These oxyhalide and oxide systems.

studies have been virtually confined to

Oxyhalide Complexes. (Ph,A)[CrO,X] (A = P or As and X = F or Cl) have been precipitated from a solution of the corresponding potassium salt in dilute H F or HCl and their unit cells, i.r., and electronic spectra reported.733 The interactions of Cr02Cl, with aromatic hydrocarbons and fluorocarbons have been examined and the intermolecular charge-transfer transitions recorded.734

0-Donor Ligands. The d.t.a. characteristics of chromates and isopolychromates have been r e v i e ~ e d ' ~and ' the heats of formation of several alkali-metal and 728

'29

730 731

732 733

734

J. Slivnik and B. Zemva. Z . anorg. Chem.. 1971. 385. 137 ( a )D. P.Sinha, Indiati J . Phys., 1971,45. 187;(b)G.Le Flem, R. Olazcuaga, J. P. Parant, 3. M. Reau, and C . Fouassier, Compt. rend, 1971,273, C, 1358. M . Miteva, P. R. Bontchev, and V. Vozhinov, Inorg. Nuclear Chem. Letters, 1972,8, 51. Z. I . Usmanov, A. V. Il'yasov, and I. D . Morozova, Muter. Nauch. Konf. Inst. Org. Fiz. Khim., Akad. Nauk S.S.S.R., 1970. 82. P. D. Dacre and M. Elder, J.C.S. Dalton, 1972, 1426. E. Diemann, E. Ahlborn, and A. Miiller, Z . anorg. Chem., 1972,390, 217. P. R. Hammond and W. S. McEwen, J . Chem. SOC. ( A ) , 1971,3812.


109

alkaline-earth chromates determined.73* 7 3 6 Ra man data on [Cr'*O,I2- has been published2" and new high-energy bands ( 2 185 nm) observed in the electronic absorption spectrum of [Cr0,]2-.737 By combining the soft X-ray Cr-bI,, Cr-K, and 0 - K emission and absorption spectra an empirical M O scheme has been produced for [Cr0,I2- which involves 3t, as the highest filled M0.610 The crystal structure of K,CrO, has been redetermined and the three independent Cr-0 bond lengths have been obtained as 163.6(3), 164.3 (3), and 165.1 (2) pm. The effect of electrostatic crystal forces on the anions compresses the bond lengths and, in the absence of such forces, the Cr-0 bond length was calculated to be 165.3 pm (or 167.0 pm when corrected for the effects of thermal motion).738Other crystal-structuredeterminations involving [CrO,], ions which have been reported this year include those of NaNH,CrO,,2H20,'39 MgCr04,5H20?"' Ag2Cr04;/"' p-NH4Fe[Cr0,],:42 KFe[CrO,],,2H,0,743 and ~ ~ - C U ~ ( O H ) , C ~PbCrO,, O,.~~~ m.p. 920 "C, and Pb,CrO,, m.p. 804 "C, having been identified in the PbO-PbCrO, system and the former shown to be isomorphous with Pb,XO, (X = S or Se).745The solubility product of Ag,CrO, in water has been determined by conductometric, spectrophotometric, tracer, and pH measurements as 2.76 f 0.08 x 10- l 2 at 298 K.746 I.r., t.g.a,, and X-ray diffraction studies have established that the formula of Adkins' basic ammonium chromate is Cu0,~CuCr207,(NH,),Cr04,~CU(NO,),.~~~ The equilibrium constant for the equilibrium 2Cr0:- + 2H' =' Cr,O;- + H,O has been determined spectrophotometrically as 1.3 Ifi 1.0 x lo', at 25°C.748The crystal structures of P-Na2Cr207,749NaMCr207(M= Rb or C S )5~0 and the magnesium dichromate hexahydrate-hexamethylenetetramine addition compound, MgCr, 0 7,6H 0 , 2 [( CH 2)6N4],7 have been solved. In Rb,Cr3010 the trichromate ions consist of three CrO, tetrahedra sharing corners and in RbCr,Ol, the tetrachromate ions consist of four such cornersharing tetrahedra. In these anions the terminal and bridging Cr-0 bonds

,

E. L. Charsley, 'Differential Thermal Analysis', ed. R. C. MacKenzie, Academic Press, London, 1970. 7 3 6 A. A. Shidlovskii, T. N. Balakireva, and A. A. Voskresenskii, Zhur. fiz. Khim., 1971,45,1857, 1868. 7 3 7 A, Miiller and E. Diemann, Chem. Phys. Letters, 1971, 9, 369. 7 3 8 J. A. McGinnety, Acta Crysta., 1972, B28, 2845. 7 3 9 A. A. Khan and W. H. Baur, Acta Cryst., 1972, B28,683. 7 4 0 W. H. Baur and J. L. Rolin, Acta Cryst. 1972, B28, 1448. 7 4 1 M. L. Hacker? and R. A. Jacobson, J . Solid State Chem., 1971,3, 364. 7 4 2 A. Hardy and F. Gaboriaud, Acta Cryst., 1972, B28, 2329. 743 P. Gravereau and A. Hardy, Acta Cryst., 1972, B28,2333. 744 A. Riou, Compt. rend., 1972,274, C , 1572. 7 4 5 J. C. Ruckman, R. T. W. Morrison, and R. H. Buck, J.C.S. Dalton, 1972, 426: V. T. Mal'tsev, G. A. Bukhalova, and V. M. Manakov, Zhur. neorg. Khim., 1972,17, 532. 746 A. L. Jones, G. H. Linge, and I. R. Wilson, Austral. J . Chem., 1971,24, 2005. 7 4 7 S. Shishido and T. Takajo, Sci. Reports Niigata Univ., Ser. C , 1971, 35. '" J. A. Smith and C. R. Metz, Proc. Indiana Acad. Sci., 1970,80, 159. 749 N. Ch. Panagiotopolos and I. D. Brown, Acta Cryst., 1972, B28, 1352. 7 5 0 N. Ch. Panagiotopolos and I. D. Brown, Acta Cryst., 1972. B28,2880. 7 5 1 F . Dahan, Compt. rend., 1971,273, C , 805. 735


110

have lengths of 155-161 and 170-186 pm, respectively.752The vibrational spectra of CrO,, [Cr3010]2-, and [Cr,Ol3l2- have been measured and the ~~ unit-cell parameters of P-Cs,[Cr,O,,] and Cs,[Cr,O,,] p ~ b l i s h e d . 'Other studies of compounds containing chromate and polychromate anions are listed in Tabie 8. Table 8 Studies on compounds containing chromate or polychromate ions Compound

Cornnients and reported properties

Ref. a

FeCo[CrO], CoCrO,

i.r., X

b

Ld.. X

C

X spinel Fe"'[Co"C?"]O, high-pressure oxygen synthesis, X CrV0,-type structure

d

-+

-+

e

f 9 (uj M. Grabowski. A. Stepien, and E. Wajsman, SOC.Sci. Lodz., A m Chim., 1971, 16, 13. (b) P. P. Cord, P . Coutine, and G. Pannetier, Bull. SOC. chim. France, 1971, 2461. (cj A. Bonnin and A. Riou, Compt. rend., 1971. 272, C. 1551, (d)D. K. Kulkarni and C. Mande, J. Phys. (D), 1971.4, 1218. ( e ) S. Kume. F. Kanamaru, Y. Shibasaki, M. Koizumi K. Yasunami, and T. Fukuda, Rev. Sci. Instr., 1971, 42, 1856. ( J )B. Sandilya. A. Roy, and S. K. Ghosh. Technology, 1970, 7, 292. @) I. J. Martin, J. V. Carcia, P. J. Alonso, and R. I. Escalante, Ion (Madrid), 1971,31,623; G. Aravamudan and S. Sampath 'Proceedings of the 2nd Chemical Symposium,' Dept. Atomic Energy, Bombay, 1970, vol. I , p. 313.

[HCrO,]- has been shown to be the photo-active species in the photochemical reaction of dilute solutions of chromium(v1) oxyacids with alcoholic reducing agent^."^ The association of chromate with Np", ThIV,and Ferr'in perchlorate solution has been studied spectrophotometrically and the respective formation constants, 63.6,4.70, and 1.93, have been determined. The greater stability of the Np'" complex has been interpreted in terms of the limited donation of Sf-electron density from NpiVto the d-orbitals of chromium in the chromate ion.755 CrO,Cl,, K,CrO,, and K,Cr,O, form Cr0,(HS04), when dissolved in disulphuric and the reaction of CrO,Cl, with fluorosulphonic Dilithium perfluoroacid affords a convenient synthesis of Cr02(S03F)2.756 pinacolate Li,[(CF,),CO], reacts with CrO,Cl, to form [CrO,{(CF,),752

753 754

755 756

P. Lofgren, Acta Chem. Scand., 1971, 25, 3893. R. Mattes, Z . anorg. Chem., 1971,382. 163. M. Sasaki, K. Honda, and S. Kikuchi, Bull. SOC.Photogr. Sci. Technology, Japan, 1970, 18. M. J. Burkhart and R. C. Thompson, J . Amer. Chem. SOC.,1972,94,2999. R. C. Paul, K. K . Paul, and K. C. Malhotra, Indian J . Chem.. 1971,9, 718.


111

CO},] [see (19)].,* The formation constants of [HCrPO,]- and [H,CrPO,]have been determined spectrophotometrically as 6.25 and 21.0, r e ~ p e c t i v e l y . ~ ~ N-Donor Ligands. CrO, forms a 1: 1 complex with hexamethylenetetramine, the i.r. and electronic spectra of which indicate that the metal has a pseudotetrahedral (C3”)environment.758

6 Molybdenum and Tungsten Introduction.-A review discussing the properties of the molybdenum -containing enzymes, in particular the e.s.r. characteristics of xanthine ~xidase,’~’ and a text describing the analytical chemistry of molybdenum and tungsten,760 have been published. The seventh ionization potential of molybdenum has been estimated as 129.O4l3Oand 125.66 eV13’ from spectral studies. Several notable developments in the chemistry of these elements have been reported this year. Complexed molecular nitrogen has been converted into an organo-nitrogen compound. The dinitrogen complex trans-[W(N,),(diphos),] reacts with organic acid chlorides RCOCl to form [WCl,(diphos),(N,HCOR)] from which HCl can be removed to give [WCl(diphos),(N:NC(O)R)], chelated aroyl- and acyl-azo-NO-complexes (68).761A series of novel N=N

arylimido-derivatives [Cl,(PMe,Ph)Mo(=NR)(NR: NC(O)R] has also been isolated.762Tertiary phosphines have been shown to be useful ligands for the synthesis of polyhydro-complexes, and complexes of the type [WH6(PR;)3]763 and [MH,(PR,)4]764 (M = Mo or W) have been obtained and shown to be fluxional molecules. Dichlorocarbene has been inserted into a W-H bond to give [(n-Cp),WH(CHCI,)], the first example of such an insertion into a bond involving a transition-metal atom.765 757 758 759

760

761

762 763 764

765

0. Lukkari, Suomen. K e m . ( B ) , 1972,45, 1. J. Sala-Pala and J. E. Guerchais, Bull. SOC. chim. France, 1971, 3178. R. C. Bray and J. C. Swann, Structure and Bonding, 1972,11, 107. W. T. Elwell and D. F. Wood, ‘Analytical Chemistry of Molybednum and Tungsten’, Pergamon, Elsmford, New York, 1971. J. Chatt, G. A. Heath, and G. J. Leigh. J.C.S. Chem. Comm., 1972,444. J. Chatt and J. R. Dilworth, J.C.S. Chem. Comm., 1972, 549. J. R. Moss and B. L. Shaw, J.C.S. Dnlton, 1972, 1910. (a) B. Bell, J. Chatt, G. J. Leigh, and T. Ito, J.C.S. Chem. Comm.,1972, 34; (b) J. P. Jesson, E. L. Muetterties, and P. Meakin, J . Amer. Chem. SOC.,1971,93, 5261. K. S. Chen, J. Kleinberg, and J. A. Landgrebe, J . C . S .Chem. Comm., 1972, 295.

112


X-ray studies have shown that the compound previously reported as [Mo(CH,SiMe,),] is in fact [Mo,(CH2SiMe,),], with a short Mo-Mo triple the cation is a bond of length 216.7 pm.766 In [(x-Cp),MoS,]+[Me,SnCl]triangular Mo'" cluster with doubly and triply bridging sulphur atoms,767 involves a non-linear and [{ R~,MO(~-C~)(CO),)S{SMO(~-C~)(CO)~~~] Mo-Re-Re system with all the metal atoms bridged on one side of their plane by the lone sulphur atom, and on the other by a {SMo(x-Cp)(CO),) ligand.768 The chemical transport of MOO, with iodine in a temperature gradient suggests the existence of MoO,I, in the vapour phase.769The remarkable elimination-stabilized alkyl WMe, has been obtained by the interaction of WCl, with LiMe in ether and shown to be reasonably inert to chemical attack.770 Carbonyl Complexes.-n-Aryl carbonyl complexes are included in this section. The heat of formation of [Mo(CO),] has been determined as -960 & 12 kJ mol- by measuring its heat of d e c o m p o ~ i t i o nThe . ~ ~ Mossbauer ~ parameters for the 100 keV transition of lS2Win [W(CO),] and some tungsten(v1) complexes have been measured and discussed in terms of known bonding and ( M = Mo, rn = 1 or 2; M = W, structure.77' Secondary ions [MJCO),]' rn = 1-4; n = 0-14) formed by ion-molecule reactions have been observed in themassspectraofthe hexacarbony1s.A mixtureof[Cr(CO),] and [Mo(CO),] [Mo(CO),] and [W(CO),] vapours affords [CrMo(CO),]+(n = 5-7).'" catalyse the condensation of isocyanates with aldehydes to give imines in high yields. O9 The photolysis of [M(CO),] (M = Cr, Mo, or W) has been studied in detail this year. Two species with absorption maxima at 405 and 415 nm have been observed in cyclohexane solution subsequent to the flash photolysis of [ M O ( C O ) , ] . ~Spectroscopic ~~ studies of [M(CO),] species formed by the photolysis of the hexacarbonyl trapped in low-temperature matrices agree that only a square-pyramidal (C,") structure is adopted. No evidence was obtained to support the earlier postulate that a D,, structure is formed when pentanemethylcyclohexane or hydrocarbon glasses melt.507. The first identification of a radiative deactivation pathway for metal carbonyl complexes has been reported for a series of [W(CO),L] complexes, including [W(CO),] itself, and also for [W(CO),] prepared in a methyl-cyclohexane glass. The fact that the emitting state has the same energy for [W(CO),] and [W(CO),L] suggests that the axially symmetric ligand field in the latter is dominated by the carbonyl group trans to L.772 '66

767

768 '69 770

17' 772

F. Huq, W. Mowat, A. Shortland, A. C . Skapski, and G . Wilkinson, Chem. Comm., 1971, 1079. P. J. Vergamini, H. Vahrenkamp, and L. F. Dahl, J . Arner. Chem. SOC.,1971,33, 6327. P. J. Vergamini, H. Vahrenkamp. and L. F. Dahl, J . Amer. Chem. Soc., 1971,93, 6326. H. Opperman, 2. anorg. Chem., 1971,383,285. A. Shortland and G. Wilkinson, J.C.S. Chem. Comm.,1972, 318. G. M. Bancroft, R. E. B. Garrod, and A. G. Maddock, Inorg. Nuclear Chem. Letters, 1971,7, 1157. H. B. Gray, M. Wrighton, and G. S. Hammond, J . Amer. Chem. SOC.,1971,93,4336.


113

I3C n.m.r. spectra have been reported for several carbonyl complexes of molybdenum and tungsten, which clearly distinguish between different stereochemical environments of the CO groups in any one c o m p o ~ n d'.2-5~ l4 In the series of compounds [W(CO),L] [L = P(OPh),;P(OBu),, PPh(OBu),, PPh,(OBu), NH,C,H,,, or APh,, where A = P, As, Sb, or Bi] a linear relationship between the Cotton-Kraihanzel carbonyl stretching force constant and the corresponding I3Cchemical shift has been established. This suggests that, for a given metal, changes in M-C-0 n-bonding exert a dominant influence over the I3C chemical shifts.5131.r. spectra in the regions 2100-1800 and 700--300cm-' of a large number of monosubstituted [M(CO),L] and cis[(bidentate)M(CO),] (M = Cr, Mo, or W) complexes have been reported. The positions of the M--C stretching modes were found to be determined by the 0-donating ability of the ligand L, and the reactivity of the complex via ratedetermining dissociation of CO was shown to correlate with the positions of the v ( M 4 ) stretches.525 The crystal structure of [(n-Cp)W(CO),AlMe,], has shown that the dimeric units (69) are centrosymmetric with the oxygen atoms of the carbonyls linked

0

0 Me

to AIMe, units to form a slightly puckered twelve-memberd ring. In this ring the W-C bonds [181(3) pm] appear to be short compared with the terminal bonds of the compound [194(3) pm]; however, all the C-0 bond lengths (124and 125 pm)appearto belongerthanthoseinothercarbonylcompounds.773 The new, air-sensitive, polynuclear complexes (Me,N)[(x-Cp),M,Fe,(CO),,] (M = Mo or W) have been synthesized by the reaction of [(n-Cp)M(CO),] - with [Fe,(CO),] at room temperature in T H F solution. Interpretation of i.r. and 'H n.m.r. spectra led to the structure (70) being suggested for

773

I

G . J. Gainsford, R. R. Schrieke, and J. D. Smith, J.C.S. Chem. Comm., 1972, 650

114


these anions.774The ‘extra’ carbonyl stretching band in the i.r. spectrum of [(n-Cp)(CO),WMn(CO),1 in CCl, solution has been shown to be due to [Mn(CO),CI] formed by cleavage of the W-Mn bond by the solvent.775 1.r. stretching frequencies have been reported for the complexes trans-[L2M(Mo(n-CpHCO),),] (M = Pt or Pd, L = py or 3-Mepy) and [((7c-Cp)(CO),[(n-Cp)M(CO),I] Mo},Hg], all of which involve a linear M-Mo-M (M = Mo or W) react photolytically with Hg in benzene to give [(n-Cp)M(CO),HgI]. The corresponding reaction with [(7c-Cp)M(CO),ClJ affords [((n-Cp)(CO),M) ,Hg], and with [(n-Cp)MofCO),Br] produces this latter compound and [ ( I T - C ~ ) M O ( C O ) , H ~([(Tc-C~)W(CO),B~] B~] does not appear to react).777These [((IK-C~)M(CO),),H~] derivatives (M = Mo or W) react with tetra-alkyl thiuram disulphides. R,NC(S)-S(S)CNR, ( R = Me or Et) (1: 1) under reflux in benzene to give the corresponding metal-mercury bonded Na[(n-Cp)Modithiocarbamate complex [(n-Cp)(CO),MHg(S2CNR2)].571 (CO),] reacts with C,F,HgBr in T H F to form [C,F,HgMo(CO),(lt-Cp)]. Substitution of one C O group in this derivative by PR, (R = Ph or OPh) is readily achieved in refluxing ethanol to give the new derivatives [C,F,HgMo(CO),PR,(n-Cp)] in good yield.778 Halogeno-complexes. Halogeno-metal carbonyl complexes have been isolated for the first time as intermediates in the reductive carbonylation of molybdenum and tungsten halides using hydrocarbon solvents whence they are obtained as precipitates.”’ X-Ray studies have shown that the anion of the salt (Et,N) [W(CO),Br,] has a capped octahedral (C3J structure, with a carbonyl group in the capping position.780”[(~r-Indenyl)Mo(CO),I]has been shown by X-ray to resemble [(x-Cp)Mo(CO),X] derivatives, and thus the original formulation of it as a sixteen-electron compound is correct. A variety of compounds (R,N),[(CO),MX,M(CO),] (R = Me or Et; M = Mo or W; X = F, C1, Br, or I) have been isolated by refluxing a 3: 1 mixture of R,NX and M(CO), or [(n-arene)M(CO),]. These compounds probably involve triply bridged anions analogous to (47). Double halogenobridged anions are believed to be present in the salts (Ph,As)2[(C0)3MoC12Mo(CO),] and (Et,N)2[(CO),Mo12Mo(CO),] prepared by the reaction of Ph,AsCl (1 : 1.75) or Et,NI (1: 1) respectively, with [ ( n - t ~ l u e n e ) M o ( C O ) , ] . ~ ~ ~ Thequaternary iodide N,P4Me91 reacts with [Mo(CO),] to give [N4P,Me9][Mo(CO),I) in which i.r. and ‘H n.m.r. spectra indicate a donor-acceptor interaction between the ions.516 The oxidation of trans-[M(CO),(PPh,),] (M = Mo or W) with I, has been reinvestigated and the Scheme 5 suggested as 174

775 i’6 771

’”

’’’ 780

A. T. T. Hsieh and M. J. Mays. J. Organometallic Chem., 1972,39, 157. S. A. R. Knox, R. J. Hoxmeier, and H. D. Kaesz, fnorg. Chem., 1971.10, 2636. P. Braunstein and J. Dehand, J.C.S. Chem. Comm., 1972, 164. A. N. Nesmeyanov, L. G. Makarova, and V. N . Vinogradova, Izvest. 4kad. Nauk S.S.S.R., Ser. khim., 1972, 122. T. A. George, J . Organometallic Chem., 1971,33, $33. L. Bencze, J . Organometallic Chem., 1972,37, C37. (a) M. G. B. Drew and A. P. Wolters, J.C.S. Chem. Comm.. 1972, 457: ( h ) A. Mawby and G . E. Pringle, J . Inorg. Nuclear Chem.. 1972.34, 525.


115

a reaction pathway since [M(CO),I,] was isolated as an intermediate. This appears to be a general reaction for phosphine ligands and the new compounds (LH)[M(CO),LI,] (L = rn- or p-tritolylphosphine) have been prepared for molybdenum and tungsten.781

+ I,

trans-[M(CO),(PPh3),]

[PPh H] [M(CO)3(PPh,)I3]

\

A+

[M(CO),I,]

+ 2PPh3

protonic solvent

Scheme 5

0-, S-, and Se-donor Ligands. X-Ray photoelectron spectra for an olefin disproportionation catalyst prepared by condensing [Mo(CO),] on to y-Al,O,, indicate that the metal does not exist as the hexacarbonyl but that it is displaced to higher binding energies. It was concluded that the active species in catalysts of this type are Mo"' entities (with n > 0) attached to less than six electronwithdrawing sites on the alumina.782 Theanioniccarboxylates [M(CO),(RCO,)]- (M = Mo, R = C,F,; M = W, R = H, Me, Et, Ph, CF,, C2F5, or C,F,) have been isolated as their bis(tripheny1phosphine)iminium (Ppn) salts by the reaction of the appropriate (Ppn),[M,(CO),,] compound with the corresponding silver(1) or mercury(r1) carboxylate, in CH2C1, at room temperature. (Et,N)[W(CO),(CF,CO,)] has also been prepared by heating W(CO),'and (Et,N)CF3C0, in diglyme at 120 "C. U.V. irradiation of [W(CO),(CF,CO,)]- with Ph,P in THF affords [W(CO),(CF3C0,)PPh,]-.5 "[Ni(salen)] reacts with [Mo(co),] or [w(Co),] (1: 1)under reflux in xylene to give the [Ni(salen)M(CO),] derivative. A comparison of their i.r. spectra with those of similar complexes suggests the structure (71) for these complexes.783

'HC=

(71)

M

=

Moor W

The crystal structure of [W(OH)(CO),H],,4Ph2EtP0 has been determined. In the tetrameric units (72) the metal atoms occupy the corners of a regular tetrahedron and are held together by four p,-hydroxy-groups so that the W,O, moiety forms a distorted cube. The metal-atom separations of 348 pm are too long for any bonding interaction. The arrangement of ligands about 782

J. A. Bowdon and R. Colton, Austral. J . Chem., 1972, 25, 17. D. A. Whan, M. Barber, and P.Swift, J.C.S. Chem. Comm., 1972, 198. M. D. Hobday and T. D. Smith, J . Chem. SOC. ( A ) , 1971, 3424.

"'

116

inorganic Chemistry of the Transition Elements

each metal atom allows the position of the hydridic hydrogen to be determined, the co-ordination geometry involving a W(CO),H square pyramid and a W(OH), tetrahedron sharing a common vertex. The Ph,EtPO molecules are joined to the tetramer by strong hydrogen bonds to the p3-hydroxo-groups.784

/-I

/ P"

Triply bridged anions [(CO)3MX,M(CO)3]3- (M = Mo or W, X = OH; M = Mo, X = OEt) and the doubly bridged species [(CO),Mo(OH),Mo(CO),]'- have been prepared in an analogous manner to the corresponding halogeno-complexes described above.' [(x-Cp)(CO),MoCH,Ph] reacts with SO, to form the 0-bonded sulphinato-intermediate, which subsequently rearranges to the corresponding S-bonded derivative, [(n-Cp)MoS(O)OCH,Ph].785 Monothiothenoyltrifluoroacetone (ttas) forms [M(CO),(ttas)] (M = Mo or W), in which it acts as a unidentate S-donor ligand, in the reaction between [Tl(ttas)] and (Et,N)[M(CO),CI] (M = Mo or W). The complexes lose C O on heating to afford the corresponding [M(CO),(ttas)] - derivative, in which the ligand acts as a bidentate 0-and S-donor.'" Thiazolidine-2-thione (48) (L) reacts photolytically with [Mo(CO),] or [W(CO),] in toluene to give the [M(CO),L] complex which involves co-ordinaBis(trifluor0tion of the ligand cia the S-atom of the thioketonic methyl) disulphide, CF,SSCF,, reacts under photolysis with [(n-Cp)Mo(CO),I] or [(x-Cp)M(CO),], (M = Mo or W) to give [(n-Cp)M(CO),SCF,]. The molybdenum compound is readily decarbonylated to afford the dimer [( n-Cp)Mo(CO), SCF,] ,. 8 6 [(n-Cp)Mo(CO),Cl] reacts with Et2P(S)SNa,2H,0 in T H F at 65 "C to give [(7c-Cp)Mo(CO),S2PEt] in 60% yield. The i.r. spectrum of the complex indicates bidentate bonding of the phosphinate and cis-carbonyl The methylthio-bridged complexes M1(SMe)M2 [MI = (x-Cp)(CO),Fe, (x-Cp)(CO),Mo, (n-Cp)(CO),W, or Ph,PAu, and M 2 = Cr(CO),, W(CO),, or Mn(CO),(n-Cp)] have been prepared by the reaction of [M'SMe) with M2, or of [Me,Sn(SMe)M2] with M'C1, and their i.r. and 'H n.m.r. spectra recor784 785

786

"'

V. G . Albano, G . Ciani, M. Manassero, and M. Sansoni, J . Organornetallic Chem., 1972,34. 353. S. E. Jacobson, P. Reich-Rohrwig, and A. Wojcicki, Chem. Comm., 1971. 1526. J. L. Davidson and D . W. A. Sharp, J.C.S. Dalton, 1972, 107. E. Lindner and K. M. Matejcek, Z . Naturforsch., 1971,26b,854.


117

ded.522[(n-Cp),Nb(SMe),] reacts with [(n~rbornadiene)Mo(CO)~] to give the Similar' complexes bis(methy1thio)-bridged [(~-C~),N~(SM~),MO(CO)~].~~~ [(L-L)M'(SR),M2(CO),] (L-L = diphos or diars, M' = Pd or Pt, R = Me or Ph, and M2 = Mo or W) have also been prepared from [(norbornadiene)M*(CO),] and [(L-L)M'(SR),]. There is no evidence for any M'-M2 bonding in these compounds even though M' has sixteen valence-shell electrons.523The Me,SnS-bridged dimer [Re(CO),(SSnMe,)] reacts with [(n-Cp)Mo(CO),Cl] in either 1,2-dimethoxyethane or benzene at 75 "C to form [(Re,Mo(n-Cp)(CO),}S(SMO(~-C~)(CO)~)]. The crystal structure of this compound consists of an open triangular Re-Re-Mo arrangement with a central Re(CO), fragment joined by metal-metal bonds with another Re(CO), group and a (n-Cp)Mo(CO), group. These three metal atoms are all bridged on one side of their plane by a single sulphur atom and on the other side by a (SMo(n-Cp)(CO),) group. This latter sulphur links the Re,Mo unit to the other Mo atom by four o - b ~ n d s . ~ ~ ~ The addition of the ligands Me,PS, Me,PhPS, Ph,PS, Me,AsS, and Me,PhPSe (L) to u.v.-irradiated THF solutions of [w(co)6] has afforded the new [W(CO), L] derivatives. The corresponding molybdenum compounds could be isolated only with difficulty and in lower yield. 1.r. spectral studies have shown that the complexes probably involve a non-linear M-S(Se)-P arrangement.',, N-, P-, As-, and Sb-donor Ligands. The rate constant for the first-order thermal decomposition of [M(CO),amine] complexes (M = Mo or W) has been found to decrease with increasing pK, of the amine, consistent with cleavage of the M-N bond as the rate-determining step. Analogous compounds with unsaturated amines, e.g. py, are much more stable than their pK, values would predict, suggesting some M-N back bonding.527 The complexes [(CO),MN,H,M(CO),] (M = Cr or W), involving hydrazine as a bridging ligand, have been prepared by the reaction of [(CO),M(THF)] with [(CO),M(N,H,)] or N2H4.528(R,N),[(CO),MoX,Mo(CO),] (R = Me or Et, X = N, or NCS) have been prepared by refluxing [Mo(CO),] and R,NX.," N 3 reacts with [W(CO),] to afford [W(CO),NCO]-, which has been isolated as its [Ph,As]+ salt.7 8 8 Electron-impact ionization potentials have been determined for [W(CO),L] (L = 2,6-Mepy, 4-Mepy, or 2-CNpy) and for the free ligands. A good linear correlation was obtained between 'the two values in this and other series of compounds and the results were rationalized in terms of a synergic bonding mechanism.520 [(bipy)Mo(CO,], [(bipy)W(CO),], and related compounds have been reduced with sodium in THF. The electronic and e.s.r. spectra of the products suggest that they involve the uninegative ion of bipy as a ligand.526The crystal tetrafluorostructure ofdicarbonyl-2,2'-bipyridinepyridine-n-allylmolybdenum borate has been determined and the cation shown to have the pseudo-octahedral

,

M. J. Lofquist, Diss. Abs. ( B ) , 1971,31, 3903.

118


structure (73).' 89 2-Pyridinecarboxaldehyde imines [(49) p. 811 react with [Mo(CO),] or [W(CO),] under U.V.irradiation to form the corresponding [(NC,H,CH: NR)M(CO)J derivatives (50). Ph,P readily substitutes for one carbonyl group in these complexes.530 [Mo(CO),] and [w(Co),] react with the N-donor ligands l&naphthyridine, 2-methyl-1,8-naphthyridine,

and trans-decahydro-1,8-naphthyridine(L) to form complexes [M(CO),L] and [M(CO),L,] which involve unidentate ligands, and [M(CO),L] which involve bidentate ligands. The carbonyls also react with 2,7-dimethyl- 1,8naphthyridine and 2,9-dirnethyl-l,lO-phenanthroline(L') to give [M(CO),L'] and further reaction of these molybdenum complexes with amines, phosphines, or phosphites (L2) affords [Mo(CO),L'L2] and [Mo(CO),L'L;]. Both the molybdenum and tungsten [M(CO),L'] complexes react with SnX,, RSnCl,, or R2SnC12(X = C1, Br, or I, R = Me, Et, Bu, or Ph) to form the seven-coordinate complexes [M(CO),( L ')X(SnX,)], [M(CO),( L ')Cl(RSnCl,)], or [M(CO),(L ')Cl(R,SnCl)], respectively.' 29 Treatment of [(K-C~)M(CO),CI](M = Mo or W) with the Schiffs base of pyridine-2-aldehyde and ( - )-or-phenylethylamine produces the cationic complexes (74). The bidentate Schiffs base functions on the one hand as a ligand to lower the symmetry about the metal and on the other as an optically active agent for resolution of the racemate. These optically active enantiomeric cations are stable and have been resolved by fractional crystallization of their PF; salts.790[Mo(CO),] has been treated with some potentially quadridentate Schiff's bases and the diamagnetic complexes (i) dicarbonyl-NN'-ethylenebis(salicylaminato)molybdenu m(rr), (ii) dicarbonylaminobis-(N-ethylenesalicylaminato)molybdenum(rI) hydrochloride, and (iii) hexacarbonyltris[bis(acetylacet0ne)ethylenedi-imine]dimolybdenum(O) have been prepared. The complexes (i) and (ii) are considered to be mononuclear, distorted octahedral complexes with cis-carbonyl groups, whereas (iii) appears to be dinuclear, with i89 790

R. H. Fenn and A. J. Graham, J. Organometallic Chem., 1972,37, 137. H. Brunner and W. A. Herrmann, Angew. Chem. International Edn., 1972.11.418.


119

fuc-carbonyls and neutral N-donor Schiffs base ligands, one of which is a bridging ligand. During the production of (i) and (ii) hydrogenation of the C=N bonds of the Schiff’s base occurs and, although this has some similarity to a proposed mechanism for dinitrogen fixation, none of the complexes is effective as a catalyst for the reduction of N2.791 +

(74)

M

=

Moor W

[Mo(CO),], [(cy~loheptatriene)Mo(CO)~],[W(CO),], and [W(CO),(MeCN),], react with the terdentate N-donor ligands (T) bis(2-pyridylmethy1)amine, bis(2-pyridylmethyl)methylamine,and bis(2-pyridylethy1)amine to form the corresponding fac-[Mo(CO),T] derivatives. The action of iodine on these complexes is to form [M(CO),(T)I]I, in which the cations are seven-co~rdinate.’~’Octamethylcyclotetraphosphonitrile,N4P4Me8, and decamethylcyclopentaphosphonitrile, N,P,Me,,, (L) form [LM(CO),] complexes with [Mo(CO),] and [W(CO),] which probably involve co-ordination of the ring nitrogen atoms. The octamethylamido-derivative, N4P4(NMe2)8,forms the tetracarbonyl derivative [N,P,(NMe,), W(CO)4].5 BB‘B”-trirnethyl-NN’N”triethylborazine and BB’B”-triethyl-NN’N”’-trimethylborazine (L)react photolytically with fuc-[Mo(CO),(MeCN),] or [MO(CO),] to form the n-complexes [LMo(CO),]. These compounds are less stable than the corresponding chromium derivatives and the borazine-metal bond is cleaved by Lewis bases.792 The crystal structure of tetrakis(l-pyrazolyl)borate(h5-cyclopentadienyl)dicarbonylmolybdenum (75) has been determined and is the first characterization of a bidentate tetrakis( 1-pyrazolyl) ligand. The cyclopentadienyl group is tilted on the Mo-h5 centroid, the Mo-C distances ranging from 226 to 242 pm. The six-membered ring is in a rather flattened boat conformation (76) and in s o htion its interconversion with another conformer has been followed by ‘H n.m.r. spectroscopy and the activation energy estimated as 42 kJ mol-1.793 1.r. and ‘H n.m.r. data indicate that hydridotris(pyrazolyl)borate, HB(pz),. and diethylbis(pyrazolyl)borate, Et2B(pz),, in [{ HB(pz), )Mo(n-Cp)(CO),] 791

792 793

P. C. H. Mitchell and D. A. Parker, J.C.S. Dalton, 1972, 1828. K. Deckelman and H. Werner, Helu. Chim. Acta, 1971,54,2189. J. Calderton, F. A. Cotton, and A. Shaver, J . Organometallic Chern., 1972,37, 127.


120

[(Et,B(p~),)Mo(rc-Cp)(C0)~]are also co-ordinated as bidentate ligands forming six-membered rings which exist in two conformations. These studies confirm the explanation previously proposed for the temperature dependence . ~ ~ ~ studies of the 'H n.m.r. spectrum of [ ( B ( p ~ ) , ) M o ( r c - C p ) ( C 0 ) ~ ]X-Ray

B

have shown that in !,dihydrobis(3.5-dimethyl-l-pyrazolylborato~(~-allyl)dicarbonylmolybdenum, [{ H2B(Me,pz),) Mo(rc-C3H5)(C0),] (77) the metal has slightly distorted octahedral geometry, the Mo-H separation of 230 pm

H-

I

B--H

I

\/

*.**Mo,

/ \

C l O

N-N C M e v M e 'o

being too short for a non-bonded distance. If the two electrons of the B-H bond are included, the metal has eighteen electrons in its valence Stereochemical non-rigidity has been identified in some (poly(1 -pyrazolyl)borato}-(rc-ally1)dicarbonylmolybdenum complexes (78) by 'H n.m.r. spectroscopy. The mechanism involves an internal rotation of the RIB(pz), group about the B-Mo axis, and has an activation energy of 57-62 kJ mol-' (R' = H > Ph > Me).796 The properties and reactions of the molybdenum and tungsten complexes [(.-Cp)M(CO),(N: CPhBu')] {,,:sely resemble those of the corresponding di-t-butylmethyleneamino-complexes, steric hindrance preventing bridging by the methyleneamino-groups. The complexes react with iodine to form [(n-Cp)M(CO)I,(NCPhBu')] as expected; however, in contrast to all other such 794

'95

796

J. Calderton, F. A. Cotton, and A. Shaver, J . Organometallic Chem., 1972,38, 105. C. A. Kosky, P. Ganir, and G. Avitabile, Acta Cryst., 1971, B27, 1859. P. Meakin, S. Trofimenko, and J. P. Jesson, J . Amer. Chem. SOC., 1972,94, 5677.


121

methylamino-complexes, the molybdenum complex reacts with Ph3P to form [(n-Cp)Mo(CO)PPh,(N: CPhBu')]. [(n-Cp)Mo(CO),(HN: CPhBu')Cl) is formed by the reaction of PhBu'C: NSiMe with [(~-Cp)Mo(C0),Cllin monog l ~ m e [(n-Cp)M(CO),Cl] . ~ ~ ~ (M = Mo or W) react with (p-tolyl),C:NLi to produce the three types of complex, [(n-Cp)M(CO),(N: C(p-tolyl),}], [(n-Cp)M(CO), {(p-tolyl),C :N :C(p-tolyl),}], and [(n-Cp)M(CO), {(p-tolyl),C :N :C(p-t~lyl)~)(p-tolyl)~CO], which have been characterized by 1.r. and H n.m.r. * spectroscopy. The second of these types are fluxional m0lecules.7~

R'

R' = H, Me, or Ph, R2 = H or R1 = H, Me, Ph, or Br, R2 = pz

The molecular structure of [Mo(CO),PF,] in the gas phase has been determined by electron diffraction studies and the Mo-P bond length reported as 236.9(1.0)pm.799 The positive and negative ion spectra of [Mo(CO),PF,], cis- and trans-[Mo(CO),(PF,),], mer- and fuc-[Mo(CO),(PF,),], and [Mo(PF,),] have been studied and appearance potentials measured for the first complex. This study has indicated that after ionization the Mo-PF, bond is weaker than the MO-CO.~" The use of [Ni(PF3)4] in boiling toluene as a convenient source of PF, in syntheses has been demonstrated by preparing [(n-Cp)Mo,(CO),PFJ, [(n-Cp)Mo(CO),PF,],, and [ M ~ M ( ~ - C P ) ( C O ) ~ P F ~ ] (M = Mo or W). The formation of the latter complexes from [MeM(n-Cp)(CO),] indicates that substitution of PF, for C O is preferred to insertion into the Me-M bond.*" [MeMo(n-Cp)(CO),] reacts with Me,NPF, in MeCN to give the yellow acetyl derivative [(n-Cp)Mo(CO),(COCH,)( PF,NMe,)] ; however, the analogous reaction with the N-piperidino-derivative produces cis-[(C, H, ONPF2)4Mo(CO),]. U.V. irradiation of [(n-allyl)Mo(n-Cp)(CO),] with Et,NPF, 797 798

799

M. Kilner and J. N. Pinkney, J . Chem. SOC.( A ) , 1971,2887. H. R. Keable and M. Kilner, J.C.S. Dalton, 1972, 153, 1535. D. M. Bridges, G . C. Holywell, D. W. H. Rankin, and J. M. Freeman, J. Organornetallic Chern., 1971,32,87. R. E. Sullivan, Diss. Abs. ( B ) , 1970, 31, 1141. R. B. King and E. Efraty, J . Amer. Chem. SOC., 1972,94, 3768.


122

effects substitution of one carbonyl group. [(lc-Cp)Mo(CO),CI] reacts with R,NPF, (R = Me or Et, or R,N = piperidino) to form [(n-Cp)Mo(CO),(PF,NR,)Cl] and/or [(x-Cp)Mo(CO)(PF,NR,),Cl], depending on the molar ratio of reagents. This latter derivative (with R = Me) reacts with PPh, to give the complex [(lr-Cp)Mo(CO)(PF,NMe2XPPh,)Cl], involving five different ligands bonded to the metal.,,, Bu'PF, and Bu',PF (L) complexes have been reported. [Mo(CO),] and [w(co)6] react with these ligands under irradiation in T H F solution to form [M(CO),L], and analogous reactions with [(bicycloheptadiene)Mo(CO),] and [(cycloheptatriene)Mo(CO),] afford cis-[Mo(CO),L2] and fac-[Mo(CO),L,], respectively., 3 3 P-P coupling constants in the trifluoromethylphosphino-complexes cis[Mo(CO),L,] [L = (CF,),PX (X = H, C1, or Br) or CF,PXl (Xl = H, C1, Br, or I)] have been determined. The data, together with published values for (CF,),PF and CF,PF, complexes, indicate that the magnitude of the coupling constants decreases as X = F > Cl > Br > I > H, and as X' = F > C1 Br H. cis-[((CF,),fMo(CO),] and c~s-[((CF,)~PNCS,)MO(CO),] were also prepared in this study and their solution n.m.r. spectra suggest that intermolecular phosphine exchange occurs.544 The magnitude and signs of the P-P coupling constants in cis-[Mo(CO),(PH,),] and cis-[Mo(CO),(CCl,PF,)] have been compared with those for similar complexes with Me,P and (MeO),P, and it has been suggested that ,JPMpis likely to be negative in all such cisdisubstituted octahedral complexes of Cr, Mo, and W.*02 The 183W-31P nuclear spin-spin coupling constants for [W(CO),PX,] (X = C1, Br, or I) have been correlated with the electronegativity of X.803 [M(CO),(PF,NEt,)](M = Moor W) have been prepared by thedisplacement of THF in the photochemically generated [M(CO),THF] complex by Et,NPF,. The complexes react with HBr to give [M(CO),PF,Br].536 The U.V. irradiation of mixtures of [Mo(CO),] or [w(co)6] with PrOPF,,(MeO),PF, MeP(OMe),, Me,POMe, or PMe, in pentane has been investigated in an attempt to prepare new compounds. This method was shown to be efficient for obtaining the penta- or hexa-substituted derivatives which in most cases were isolated and characterized by their i.r. and n.m.r. spectra;538 [Mo(CO),(PR,Cl)] (R = Me or Ph) react readily with water in the presence of Et,N to give [Mo(CO),(PMe,OH)] and (Et,NH)[Mo(CO),(PPh,O)], respectively. The former product involves co-ordinated dimethylphosphinous acid, the hitherto unknown tautomer of dimethylphosphine oxide. The corresponding complex of diphenylphosphinous acid was prepared by base hydrolysis of [Mo(CO),(PPh,Cl)], and from the thermal reaction of Ph,PHO with [Mo(CO),]. These two phosphinous acid derivatives react smoothly with [Mo(CO),(PMe,Cl)] in the presence of Et,N to give [(C0)5MoPMe,0PR,Mo(CO),]. The analogous reaction with (Et,NH)[Mo(CO),(PPh,O)] forms

-

'02

-

R. M. Lynden-Bell, J. F. Nixon, J. Roberts, J. R . Swain, and W. McFarlane, Inorg. Nuclear Chem. Letters, 1971, 7, 1187.

'03

E. 0.Fischer, L. Knauss, R. L. Keiter, and J. G . Verkade, J . Organometallic Chern., 1972,37, C7.


123

[(CO),MoPPh,OPPh,Mo(CO), J, the bridging system in these dimolybdenum complexes involving the rare diphosphoxan unit.*04 The bifunctional phosphorous ligand P(OCH,),P has two different phosphorus atoms but is unable to chelate to a metal atom because of its rigid bicyclic structure. The complexes [M(CO),{P(OCH,),P}] (M = Mo or W) have been prepared and ~haracterized.,~'The substituted 1,3,2-benzodioxaphosphole (79) derivatives

(79)

X

=

C1 or NEt,

[W(CO),{C6H40,PX}] have been obtained by the reaction of the appropriate ligand with [W(CO),THF]. However, derivatives with X = NCO, NCS, SPh, SMe, or OMe are unstable.805X-Ray studies of [(n-Cp)Mo(CO),(P(OMe),)I] and [(IT-MeC,H4)Mo(CO),(P(OMe),)I] have shown that the Mo-P distances of 240.6(9) and 238.8(8)pm are significantly shorter than in the corresponding PPh, derivative [248.1(5) pm], whereas the Mo-I distances are essentially constant (284-286 pm).806 [Mo(C,H,),] reacts with tertiary phosphines or phosphites [L = PPhMe,, PPh,Me, P(OMe),, PPh,(OMe), or P(OPh),] to give [(C,H,)MoL,] which, for L = PPhMe, and PPh,Me, are readily protonated by CF,C02H to form the metal hydrido-complexes [(C6H6)MoLH]+.807a The tris(dipheny1phosphino)phosphine pentacarbonyl derivatives [M(CO),{ P(PPh,),)] (M = Mo or W) have been prepared by treating [M(CO),{ P(SnMe,),}] with Ph,PCl (1:3) at room temperature under argon, and also by U.V. photolysis of (Ph,P),P and M(CO), (1: 1) in THF.539The crystal structure of [(CO),Mo(PEt,),Mo(CO),] has been determined and shown to involve two octahedra joined by a common edge (80). The Mo-Mo separation of 305.7(6) pm suggests some bonding interaction over this distance.807b

804 805

C. S. Kraihanzel and C. M. Bartish, J . Amer. Chem. SOC., 1972,94,3572. A. D. George and A. T. George, Inorg. Chem., 1972,11, 892. A. D. U. Hardy and G. A. Sim, J.C.S. Dalton, 1972, 1900, (a) M. L. H. Green, L. C. Mitchard, and W. E. Silverthorn, J . Chem. SOC.( A ) , 1971,2929; (b)L. R. Nassimberi, Inorg. Nuclear Chem. Letters, 1971,7,909.

'"' *07


124

Molybdenum and tungsten carbonyl complexes with the tritertiary phosphine (Ph,PCH,CH,)PPh (PPP), the two isomeric tetratertiary phosphines Ph,PCB,CH2P(Ph)CH2CH2P(Ph)CH2CH2PPh, (PPPP) and (Ph2PCH2CH2),P (PP,), and the hexatertiary phosphine (Ph,PCH,CH2),PCH2CH2P(CH,CH,PPh,), (PZP,), have been reported.545(PPP)reactswith [Mo(CO),] to afford [(PPP)Mo(CO),] and [(PPP)Mo(CO),], in which it is bidentate and terdentate, respectively, whereas with [(cycloheptatriene)Mo(CO),] it affords [(PPP)Mo(CO),] exclusively. The triligate trimetallic unit [(PPP)(Mo(CO),(COM~)(~-C~)]~] may be obtained by treating the phosphine with [MeMo(CO),(n-Cp)] in MeCN at room temperature. The cation [(n-Cp)Mo(CO),(PPP)] , involving a bidentate phosphine ligand, is formed when (PPP) and [(n-Cp)Mo(CO),Cl] react in benzene at room temperature, but under U.V. irradiation the carbonyl-free complex with the ligand terdentate, [(n-Cp)Mo(PPP)Cl], is produced. [Mo(CO),] reacts with (PPPP) or (PP,) in boiling toluene to afford the [(tetraphos)Mo(CO),] derivatives which contain terdentate phosphine ligands. [(norbornadiene)Mo(CO),], [(cycloheptatriene)Mo(CO),], and [(1,3-cyclohexadiene),M(C0),1 (M = Mo or W) react with the tetratertiary phosphines to afford the bidentate [(tetraphos)Mo(CO),], the terdentate [(tetraphos)Mo(CO),], and the quadridentate [(PP,),M(CO),] derivatives, respectively. The reaction of [MeMo(CO),(n-Cp)] with either of the tetratertiary phosphines in MeCN at room temperature gives the tetraligate Mo(CO),] tetrametallic derivative [(tetraphos)(M o ( C O ) , ( C O M ~ ) ( ~ - C ~ ) )[~ ]. and [W(CO),] react with (P2P4)in boiling toluene or xylene to give the hexaligate bimetallic complexes [( P,P,){M(CO),),], whereas [(norbornadiene)Mo(CO),] and (PzP4)in benzene at room temperature form the biligate monometallic derivative [( P,P,)Mo(CO)Q. The hexaligate hexametallic complex [(P,P4){MO(CO)2(COMe)(7c-Cp)]6]is obtained when [MeMo(CO),(n-Cp)] and the ligand react in MeCN at room temperature. Tungsten carbonyl complexes [W(CO),L] [L = Ph2P(CH,),PPh2; n = 1 or 21 and [(CO), WPPh,CH,PPh,W(CO),] have been prepared in good yield by displacing aniline from [W(CO),PhNH,]. Complexes containing positively charged ligands [W(CO),(Ph,PCH;PPh,R)] (R = Me or Ph) were prepared by quaternizing the corresponding neutral complexes.808 [Mo(CO), PH,] reacts with PH, to form [Mo(CO),PH,]- which is a sufficiently strong Lewis base to react with excess [Mo(CO),PH,] to produce [(CO),MoPH,Mo(CO),] Deprotonation of the complexes [Mo(CO),PPh,H],[W(CO),PPh2H], and [Mo(CO),(PPh,H),] has been achieved with n-butyl-lithium. The resulting lithio-compounds react in situ with Me1 to afford the corresponding PPh,Me cis-[Mo(CO),(diphos),] in CH,CI, solution reacts with NOPF, to form red tran~-[Mo(CO)~(diphos),]+ which slowly isomerizes in solution to form the yellow cis-derivative. Treatment of either isomer with NOPF, in MeNO, produces ~is-[Mo(CO)~(diphos)~](PF~)~.~~ +

'08

'09

*lo

R. L. Keiter and D. P. Shah, Inorg. Chem.. 1972,11, 191. G. Becker and E. A. V. Ebsworth, Angew. Chem. Internat. Edn., 1971,10, 186. R H. Reirnann and E. Singleton, J . Orqanometallic Chem., 1971,32, C44.


125

[(x-Cp)Mo(CO),(PBu,)I] has a sandwich structure with the (n-Cp) group on one side of the metal and the other ligands on the other with the carbonyl groups cis.'ll If PPh, is added to the solution prior to reductive carbonylation of halides and oxyhalides of molybdenum and tungsten, the corresponding [M(CO),(PPh,),Cl,] derivative is obtained.779Qeric effects in molybdenum and tungsten carbonyl complexes with diphos and H,C(APh,), (A = P or As) ligands have been discussed.'" [Mo(CO),(diphos) Br,]'13 and [Mo(CO),(PMe,Ph)3C1,]814 have been shown to involve seven-co-ordinate molybd e n u m ( ~atoms; ~) this co-ordination number now seems to be established for such complexes. The reactions of 0-,rn-, and p-tritolylphosphines (L) with [MO(CO),] and [w(co),]under a variety of conditions of temperature, U.V.irradiation, and molar ratios have been investigated. The products obtained were of the general formula [M(CO),L] and cis- and trans-[M(CO),L,], and their i.r. and 'H n.m.r. spectra showed interesting trends for variation of the ligands. In addition, the novel derivatives [(x-L)M(CO),] were obtained with o-tritolylphosphine and characterized by their i.r., 'H n.m.r., and mass spectra.546The reactions of [M(CO),X,] (M = Mo or W; X = C1, Br, or I) with these three tritolylphosphines have also been investigated. [M(CO),I,] affords the (LH)[ M(CO),LI,] complex with m- and p-tritolylphosphines (L) and the chloride and bromide complexes afford the corresponding [M(CO),L,X,] species, each of which is in equilibrium with its dicarbonyl analogue in solution. No metal(r1) carbonyl complexes could be obtained with o-tritolylphosphine, suggesting that steric factors preclude their formation.781 L2+ [M(C0)4L'L2] Photochemical substitution reactions [M(CO),L'] CO have been investigated for M = Mo or W; L' = amine, phosphine, or 13C0. These reactions indicate the sensitivity of M-CO bonds to cleavage under u.v.visible radiation, whereas M-NR, and M-PR, bonds are inert. Syntheses of [M(CO),L'L2] (M = Mo or W, L' = PPh,, and L2 = py or piperidine) are effected in good yield when decomposition of the products is minimized. The reaction between [Mo(CO),PPh,] and 13C0 affords the axially enriched ,CO analogue, whereas [W(CO),piperidine] and 13C0 give equatorial 7 reactions of R,NPPh, (R = Me, Et, Pr, or Bu) enrichment of 1 3 C 0 . 5 3 The have been studied and with [Mo(CO),] and [(n~rbornadiene)Mo(CO)~] [(R,NPPh,)Mo(CO),] (R # Me) and cis- and trans-[Mo(CO),(R,NPPh,),l prepared. Attempts to prepare dinuclear complexes with both P and N as donor atoms yielded only P-bridged derivatives.8 I s The electronic spectra and polarographic reduction potentials of a large number of complexes [LMo(CO),PR,] and [LMo(CO),(PR,),] (L = substituted glyoxal, diacetylimines, or camphorquinone monoimines; R = Bu or Ph) have been measured and corn-

+

'

'" R. H.Fenn and J. H. Cross, J . Chem. SOC.( A ) , 1971,3312. 'I2

R. Colton, Co-ord. Chem. Rev., 1971,6, 269. M. G. B. Drew, J.C.S. Dalton, 1972, 1329. A. Mawby and G. E. Pringle, J . Inorg. Nuclear Chem., 1972,34, 517. L. K. Atkinson and D. C. Smith, J . Organometallic Chem., 1971,33, 189.

+

126


pared with the data known for the related [LMo(CO),] complexes. The results give precise information on the oxidation state of the metal and ligand and the magnitudes of 0-and n-bonding effects within these species.816 The cyanophosphine ligands Ph,PCCN, PhP(CN)2,Me,PCN, (EtO),PCN, and (Me,N)PCN (L) react with [(norbornadiene)M(CO),] (M = Cr, Mo, or W) to give the corresponding [M(CO),L], complexes which appear to have the structure (52) (p. 82). These bridged complexes react further with another molar equivalent of L or P(OMe), to form [M(CO),L2] or [Mo(CO),L{P(OMe),)], r e ~ p e c t i v e l y .The , ~ ~ complexes [(CO),W(XIMe,)SnMe,] react with Me,X2C1 (X' and X2 = P or As) to give [(CO),W(X' Me,)X2Me,], which can also be obtained by reaction between (CO),W(X'MeJC1 and Me,X2SnMe,. These products react photolytically with [M(CO),] (M = Cr or W) to form [(CO), W(X'Me,)(X2Me,)M(CO)S]. Thermolysis of the compound with X' = X 2 = P and M = Cr affords [(CO),W(PMe2)2Cr(CO)4].549 The related singly bridged complexes [(C0)5M1(XMe,)M2(CO)5] (M' = Mo or W, X = P or As, and M2 = Mn or Re) have been prepared in reasonable yield by photochemical synthesis from [(CO),M (XMe,)CI] and Na [M ,( CO),] .' 4 8 The reactions of the potentially bidentate tertiary arsine ligand (Ph,As),CH, (dam) with [Mo(CO),] and [W(CO),] have been studied using 'H n.m.r. spectroscopy to identify the mode of co-ordination of the ligand. In [M(CO),dam], [M(CO),(dam),], and [M(CO),(dam),] the ligand is unidentate, but in [M(CO),dam] it is bidentate.Thecomplex [Mo(CO),dam] wasalso obtained, which appears to be analogous to the corresponding chromium compound (p. 83).j4' The complexes [Mo(CO),L(dae)] and [Mo(CO),(dae),.,X,], [X = C1, Br, or I and dae = 1,2-bis(diphenylarsino)ethane] have been reported and two isomeric forms of the chloride and bromide mononuclear species identified. All of the dae bridged dimeric complexes can be cleaved by C O to form the corresponding mononuclear tricarbonyl complexes and by excess dae with the probable formation of [Mo(CO),(dae),X,] but the products were too labile for definitive c h a r a c t e r i ~ a t i o n . ~The ~ ' full account of the crystal structure of [Mo(CO),(dam),Br,] has been published, the metal being sevenco-ordinate with one arsenic ligand bidentate and the other unidentate,818 and the unit cell of [Mo(CO),(AsEt),] determineda81' The mass spectra of [(Me,N),M(CO),] (M = Mo or W) have been analysed; the loss of the Me,N fragment was seen to be more prominent than in the phosphorus analogues, the tungsten complexeven giving theseries ofions Me,NW(CO); and A S W ( C O ) ; . ~ ~ ~ The unusual fluorocarbon ligand geometries found in compounds of the type [CO),Mo(AsMe, CF, CFH AsMe,)I8,' are incorrect. Their X-ray and chemical properties are better interpreted in terms of disordered arrangements of molecules with normal geometries and dimension^.^"

'

9

'16 81i

*19 820

I. W. Renk and H. TomDieck, Chem. Ber.. 1972.105, 1403, 1419 M. W.Anker and R. Colton, Austral. J . Chem., 1 9 7 1 , 2 4 2 2 2 3 . M. G. B. Drew, J.C.S. Dalton, 1972. 626. C . A. S. Brickenkamp, Diss. Abs. ( B ) , 1971, 32, 198. I. W. Nowell and J. Trotter, J . Chem. SOC. ( A ) , 1971,2922.

127


Bis(diarylstibino)methanes, (R,Sb),CH, (R = Ph or p-tolyl), react with [Mo(CO),] or [W(CO),] to give the monosubstituted complexes [M(CO),((R,Sb),CH,)], whereas (Me,Sb),CH, gives [(M(CO),),(Me,Sb,CH,)], in which the ligand bridges the two metal atoms.553

Carbene Complexes. The I3C n.m.r. shifts of the carbene complexes [(CO),WCX'X2] (X' = OMe, SMe, or NHMe; X2 = Me) indicate that the carbene carbon atoms are extremely deshielded, their signals lying far outside the range normally found for organic compound^.^ Ionic carbene complexes of molybdenum and tungsten, (Bu,N)[(CO),MC(O)R], (R = Me or Ph) can be activated with alkylaluminium halides to give catalysts for the disproportionation of terminal and non-terminal olefins.8'' [(n-Cp)M(CO),NO] (M = Mo or W) may be treated in ether with one mole of LiPh and then [R,O][BF,] (R = Me or Et) to give the corresponding carbene complex [(7c-Cp)M(CO)(NO)(C(OR)Ph)]. The molybdenum complex with R = Me reacts with HNMe, to give the aminocarbene derivative. All three molybdenum complexes react with [Fe(CO),] under U.V. irradiation in benzene to give [(COj,FeC(R1jPh] (R' = OMe, OEt, or NMe,) and [(n-Cp)M o ( C O ) , N O ] . ~[(CO), ~ ~ WC(OEt)C%CPh] has been prepared by treating [W(CO),] with LiC=CPh and [Et,O][BF,]. The compound reacts with excess Me2NH to form [(CO), WC(NMe,)CH~CPhNMe,].s60A series of ferrocenyl carbene complexes [(CO),WC(X)C,H,FeC,H,] (X = 0 - NMef , OMe, OEt, NH,, NMe,, or NC,H8) has been prepared. The ferrocenyl group acts as a good electron donor and this leads to significant differences from other carbene complexes.565The structure of the nitrogeno-molybdenum complex formed by treating Na[(.rc-Cp)Mo(CO),] with diazoacetic ester, [(n-Cp)(CO),MoN NMe * C(CO,Et)COH]+, has been determined as the PF, salt and the cation (81) shown to involve a planar five-membered ring, joined to molybdenum by a carbene bond; Mo===C= 203 pm.*,,

2

The thiocarbene complex [(CO), WC(SMe)Me] has been prepared by the reaction of [(CO), WC(OMe)Me] with HSMe at room temperature. The position of the v ( C 4 )stretching frequencies, the energy barrier for rotation about the C-S bond, the ionization potential, and the dipole moment of the 821

a22

W. R. Kroll and G . Doyle, Chem. Comm., 1971,839. C. I(.Prout, T. S. Cameron, and A. R. Gent, Acta Crysr., 1972, B28, 32.


128

complex show that thiocarbene ligands lie between alkoxy- and aminocarbene lipands with respect to ligands-metal-carbonyl charge-transfer capabilit~.~

’

Complexes with Carbon, Silicon,Germanium,and Tin.[(IT-Cp)M(CO),](M = Mo or W) react with (CN),C: CXCl to form [(IT-Cp)M(CO),C(X):C(CN),]derivatives (82)in which the metal is bonded to the unsaturated cyanocarbon ~ystem.8,~

=C

/CN

‘CN

M = MoorW X = H. C1. or C N

The cationic complexes [(sc-Cp)M(CO),] (M = Mo or W) react with secondary alkylamines R2NH to form the carboxamido-complexes [(z-Cp)M(CO),C(0)NR2] which have been isolated for R = Me and NR, = piperidine. Primary amines afford the corresponding derivatives, [(IT-Cp)M(CO),C(O)NHR], and the tungsten complexes with R = Me and But have been isolated, although the molybdenum complexes were too unstable to permit this. Further -. In related studies reaction with primary amines affords [(Tc-CP)M(CO)~] MeNCO has been inserted into the W-H bond of [(n-Cp)W(CO),H] to form ~ , ) ~ Et3N as a the carboxamido-derivative [ ( T ~ - C ~ ) W ( C O ) , ( C ( O ) N Musing +

The disproportionation ofpropylene using a catalyst of [Mo(CO),] supported on alumina has been investigated. In contrast to conclusions from photoelectron spectroscopy (see ref. 782. p. 115). the reactive complex was considered to be [Mo(CO)x(propylene),-.T](sis probablj 3 or 4), the rate-controlling step being a reaction between two adjacently adsorbed propylene molecules.825 Carbonyl-olefin complexes ofmolybdenum and tungsten, [M(CO),Cl(olefin),](olefin = maleimide or maleic anhydride) have been prepared by refluxing a [M(CO),CI]- salt with the olefin in THF or diglyme for 2 h. Using benzoquinone instead of the olefin results in [MoCl(C,H,O,),] - being formed.*’(’ A simple dehydrogenation takes place when [(~c-Cp)Mo(C0),1(AsMe,-

824

R. B. King and M. S. Saran, J . Amer. Chem. SOC., 1972,94, 1784. W. Jetz and R . J. Angelici, J . Amer. Chem. SOC., 1972,94, 3799. E. S.Davie, D. A. Whan, and C. Kemball, J . Catalysis, 1972, 24, 272. F. Calderazzo and R. Henzi, U S . P. 3 598837 (Cl. 260-3263; C07d) 1971.


I29

CH,CH,Cl)] (83) is treated with Na-Hg in T H F ; the cyclic Mo---C compound so formed undergoes hydride elimination to give the cationic derivative of chelated allyldimethylarsine (84). The olefin can be displaced by cyanide. Although the corresponding cyclized derivative is formed for tungsten, no hydride elimination appears to occur.82

‘CH

,-CH

2-

CH 2Cl

(83)

(84)

Molecules of tris(diphenylacety1ene)tungstenmonocarbonyl(85) have a capped trigonal-prismatic (C3J structure. The geometry of the acetylene groups is considerably altered by co-ordination, the C-C-CPh angles being ca. 140°.828 0

I

c

Reactions of 5-acetyl-1,2,3,4,5-pentamethylcyclopentadienewith metal carbonyls provide a convenient route to various pentamethylcyclopentadienyl metal carbonyl derivatives. Thus [Mo(CO),] reacts with Me,C,COMe in boiling 2,2,5-trimethylhexane to give [MeMo(CO),(n-Me,C,)] and [(nMe,C,)Mo(CO),], and [W(CO),(MeCN),] reacts to form [MeW(CO),(n-Me5C5)].s72The order of nucleophilicity [(n-Cp)W(CO),]- > [(n-Cp)Mo(CO),PPh,)]- > [(rr-Cp)Mo(CO),1- has been establiqhed and the complexestrnns-[(n-Cp)Mo(CO),(PPh,)Kl{R = 4-[1,2-(CN), - C,F,] or4-C5F,N) k27

K

K. P. Wainwright and S. B. Wild. J . C . S . Chem. Comm., 1972, 571. R. M. Laine, R. E hfcriarty and R. Bau, J . Amer. Chem. SOC., 1972.94. 1402.

130


have been prepared.829 A series of reactions of [(Tc-P~,PC,H,)MO(CO),] (M = M o or W) has been reported. Thus diazonium salts afford [(Tt-Ph3PC,H,)M(CO),N,Ar]', acidified CX, (X = C1 or Br) gives [(n-Ph,PC,H,)M(CO),X] * . one-electron oxidizing agents produce [(rr-Ph,PC,H,)Mo(CO),];' . and acceptor species (4.9. halides of In, Cd, or Hg, or SO2) give M-bonded a d d ~ c t s . ~ ~ ' The details have now been published of the syntheses of [(n-Cp)(CO),MSiH,] ( M = M o or W) from H,SiBr and K[M(CO),(n-Cp)]. These Si--M bonds are cleaved at room temperature by H 2 0 and HCI and at slightly elevated temperatures by Me2NH. At room temperature the compounds form adducts with Me,NH and \fe,N,s'l Several other [(n-Cp)(CO), MSiX,] [M = Moor W, X, = Me,. Cl,. Br,. HCl,. or H(Me)CI:M = W, X, = MeCl,] derivatives have been obtained in an analogous manner. This study showed that the complexes are photosensitive, that they decompose in polar solvents to form [(x-Cp)(CO),M--M(CO),(n-Cp)], and that with Me,M'OSiMe, (M' = Ge or Sn) [(7r-Cp)(CO),MM'Me3] is formed.83' [(n-Cp)(CO),MSiMe,SiMe2X] ( M = Mo or W. X =Me, C1, or Br) have also been prepared by simple salt-elimination reactions and characterized by i.r. and ' H n.m.r. The crystal and molecular structure of [W2(CO),H2(SiEt2),] have been obtained. The centrosymmetric molecule contains an approximately planar (CO),WSi,W(CO), fragment in which the tungsten atoms are held together by a W-W bond [318.3(1) pm] as well as two silicon bridges. There are two distinctly different W---Si bond lengths involved in the WSi2W parallelogram, 258.6(5) and 270.3(4) pm. This feature is interpreted in terms of hydrogen insertion between W and Si in the longer distances. The environment of the tungsten atoms is then approximately pentagonal bipyr-aniidal with two axial CO groups. and equatorial bonds to two C O groups. ;i silicon and a tungsten atom, and the two-electron t hree-centre W--H--Si bond."' [(n-Cp)Mo(CO),GeCI,] and [(x-Cp)Mo(CQ),GePh 2C1] rcact with AgBF, in aromatic or co-ordinating solvents, resulting in halogen exchange and the ~ ' of [(n-Cp)formation of the corresponding GeF deri1.21i i ~ 5 . ~ Reduction Mo(CO),PPh,], with Na Hg affords a mixture of anions and addition cf Ph,GeBr or Me,SnCI to this mixture forms tl.ccll.~-l(rc-Cp)Mo(CO),(PI-'h,jGePh,] in 17 0; yield, or rmns-[(n-Cp)Mo(CO~,(PPh,SrrMe,l in 47 % yield, respectively.835 The series of compounds trnns-[(n-Cp)Mo(CO),(L)SnMe3] [L = PPh,, P(OPh),. PPh,Me. P(OCH,),CMe. AsPh,. or SbPhJ has been prepared similarly, and the PPh, derikatiies have also-been obtained by the direct reaction of [(n-Cp)Mo(CO),SnMe,] and PPh, at 160 'C. All the corn13'~

830 831 832

833 834

835

M. I. Bruce. B. L. Goodall. D. N. Sharrocks, and F. G . A. Stone, J . Organomctallic Chem., 1972. 39, 139. D. Cashman and F. J. Lalor. J . Orqunornetallic ('hem.. 1971. 32, 351. W. Malisch, H. Schmidbaur. and M. Kuhn. Angew. Chem. Internal. Edn., 1972. 11. 516. W. Malisch. J . Organometul/ic Chem.. 1972,39. C 3 . M. J. Bennett and K. Simpson. .I. Amer. Chem. Sut... 1971,93, 7156. T. J. Marks and A. M. Seyam. J . Orgartometallic Chem., 1971. 31. C62. M. D. Curtis. Inorg. Chem.. 1972. 11. 802.


131

plexes liberate SnMe, at ca. 2OO0C, but only in the case of L = PPh, or P(OCH,),CMe has the other product [((IT-Cp)Mo(CO),(L)j ,SnMe,], been ( M = Mn or W) react ( 1 : 1 ) with ~ h a r a c t e r i z e d . ~[(Tc-Cp)M(CO),SnCI,l ,~ Na,S,CNR, ( R = Me or Et) under nitrogen to form the novel heterogeneous dinuclear dithiocarbamato-complexes [( ~-Cp)(CO),MSnCl,(S,CNR,)] 8 3 - . The reactivity of Sn--Mo and Sn--W bonds has been investigated. Cleavage of these bonds in [(n-Cp)(CO),MSnMe,] is achieved by iodine or organomercury halides, to form [(n-Cp)M(CO),I] or [(n-Cp)M(CO),HgX], respectively. This study also reported the synthesis of [(n-Cp)(CO),MSn(allyl),] by treating [(allyl),SnCl] with a refluxed solution of [M(CO),] and NaC,H,. HgX, cleaves the Sn-C bond of these complexes.838 Cornplexes with Aluminium and Indium. The complexes [(E-C~)(CO), WAIR,] (R = Me or Et) have been prepared by the reaction of [(n-Cp)W(CO),H] with R,AlH. Solution i.r. spectra suggest that these complexes exist in both A1-Wand CO--Al-bonded forms.83" A comparative study of the relative utility of various methods available for preparing compounds with metal-indium bonds has been published and [{(n-Cp)(CO),Mf,InX,-,] (M = Mo or W, X = C1 or Br, and n = 1,2, or 3) have been prepared by several routes.840

Dinitrogen, Nitrosyl, Isocyanide, and Cyanide Complexes.-Spectroscopic evidence has been presented for the formation of [Mo(CO),N2] and [W(CO),N,] complexes subsequent to photolysis of the hexacarbonyls in a nitrogen matrix at 20 K.507bThe complexes [Mo(N,)(PPh,),,PhMe] and trans-[Mo(N,),{PPh,(CH,),PPh,},] (n = 1, 2, or 3) have been prepared. [Mo(acac),,R,Al] (R = Et or Bu') and a tenfold excess of PPh, in toluene react to give the former, which may be polynuclear and has an intense v(N=N) band at 2005 cm-'. In benzene or mesitylene the unsolvated compound, [Mo(N,)(PPh,),], is obtained. The new series of trans-[Mo(N,),{ PPh,(CH,),PPh,),] complexes has been prepared similarly with the corresponding phosphine, and the arrangement of ligands about the metal confirmed by an X-ray study on the n = 2 complex. The reaction of this complex with [Co(PPh,)H,] has been carried out as an inorganic model of nitrogenase, the dinitrogen being transferred to the cobalt in exchange for a hydridic hydrogeag41 trans-[Mo(N,)(diphos),] reacts photolytically with C O to form cis-[Mo(CO),(diphos),] and further irradiation gives a product formulated as [ M o ( C O ) ( d i p h o ~ ) , ] .Two ~ ~ ~new arsine bisdinitrogen complexes analogous to [Mo(N,),(diphos),] have been prepared involving 1-diphenylarsino-2-diphenylphosphinoet hane and bis-( 1 ,?-diphenylarsinoethane). The former of 836

837

838

839 840 841

842

T. A. George, Znorg. Chem., 1972,1l, 77. W. K. Glass and T. Shiels, J . Organornetallic Chem., 1972, 35, (264. R. M. G . Roberts, J . Organometallic Chem., 1972,40, 359. R. R. Schrieke and J, D. Smith, J . Organometallic Chem., 1971,31, C46. A. T. T. Hsieh and M. J. Mays, J . Organometallic Chem., 1972,37, 9. M. Hidai, K. Tominari, and Y. Uchida, J . Amer. Chem. SOC.,1972,94, 110; T. Uchida, Y. Uchida, M. Hidai, and T. Kodama, Bull. Chem. SOC.Japan, 1971,442883. D. J. Darensbourg, Inorg. Nuclear Chem. Letters, 1972,8,529.


132

these complexes is quite stable whereas the latter is both light- and air-sensiti~e.''~ trnns-[ W(N,),(diphos),] reacts with organic acid chlorides RCOCl (R = Me, Et. Ph. or p-Me0 C6H4)to form [(diphos),C1,W(N2HC0R)]. from which one mole of HCI can be removed with Et,N to give the chelated aroyl- and acylCOR)] (68). Initial investigations azo-NO-complexes [(diphos),CI W(-N=N reacts in an analogous manner. have shown that tr~ns-[Mo(N,)~(diphos)~] These reactions are of course significant in terms of the natural conversion of dinitrogen into organic nitrosen compounds.Th1A correlation between the stretching frequency and the absolute intensity of \(N=N) for dinitrogen ligands in rrans-[M(N,),(diphos),] ( M = Mo or W) and isoelectronic rhenium complexes has been established. A large i.r. intensity implies considerable back donation from the metal: hence such dinitrogen groups should be most likely to interact with Lewis acids. Electron emission spectra from the nitrogen ls-orbitals also suggest a polar N-N bond. the terminal atom having a slight negative charge. Such considerations would seem to be important for the reduction of coordinated dinitrogen molecules.8J4 N2H4 has been identified as the principal product from the reduction of N, in aqdeous solution at pH > 7 and ambient temperatures by titanium(ii1) or chromium(11) in the presence of molybdenum (v or V I ) . The presence of magnesium(I1) ions strongly activates the reduction, and in all cases the reduction is inhibited by C0.845Molybdenum(iy), after reduction in T H F solution by magnesium, has also been shown capable of fixing molecular nitrogen.846 A system composed of 2-aminoethanethiol, NaBH,, molybdenum(vi), and iron(1r) gives high yields of '5NH3 from 15N at pressures of 1 atm.847Catalystscomposed ofmolybdate and a thiol (e.g.cysteine) duplicate the properties of nitrogenase, in particular the reduction of isonitriles. The reaction is significantly stimulated by ATP and the other phosphorylating agents and inhibited by C O and N,. These results reaffirm previous conclusions concerning the role of molybdenum in binding and reducing dinitrogen. Iron salts were found to exert a co-catalytic effect on the molybdatecysteine system, perhaps indicating that iron may function as an electron-transfer catalyst, accelerating the reduction of the molybdate-cysteine complex to the catalytically active reduced form.848 The nitrogen 1s binding energy in [MoCI,(NO),diars] has been reported.595 [M(CO),(diphos)] (M = Mo or W) react with N O + to form the new cationic nitrosyl complexes [M(CO),(NO)(diphos)] +, isoelectronic with [V(CO),NO(PR3)2].535NOCl reacts with [M,(CO),Cl,] (M = Mo or W) to give new mononitrosyl derivatives which have been tentatively formulated as [M(NO)-

-

843 844 845

846

R4-

T. A. George and C . D. Seibold. Inorg. Nuclear Chem. Letters, 1972,8,465. D . J. Darensbourp. I n o r g . Chem.. 1972.11. 1436. A. Shilov. N. Denisov. 0. Efimov. N. Shuvalov. N. I. Shuvalnva and A. Shilova, Nature. 1971. 231. 460. B. Jezowska-Trzebiatowska, P. Sobota, and T. Pluzinski. ref. 593, p. 135. R . E. E. Hill and R. L. Richards, Nature, 1971,233, 114. Tc and C1 > Br.'079 Dark-red dirheniumoctachloride-hexachloropropene,Re,Cl,,hcp, has been prepared by reacting ReCl,, Re,O,, or ReOCl, with hexachloropropene (hcp) at 160-180 "C for 4-6 h. Re,Clg,hcp loses the solvent molecule at 140 "C to form a new modification of rhenium(1v) chloride, y-ReC14.10g0The reactivity of P-ReCI, in non-aqueous media has been studied and it has been shown that, when rigorously anhydrous and oxygen-free conditions are used, the reactions of B-ReC1, are quite different from those reported earlier, and rhenium(1v) complexes can be isolated in certain instances. Thus in MeCN, although some reduction occurs, cis-[ReCI,(MeCN),] is the primary product. Other reactions studied are summarized in Scheme 8.1°81 In the presence of a ketone R,CO, B-ReCI, PPh, in

trans-[ReCl,(PPh,),] [ReCI,(Ph, P)] [ReCl ,(PPh,)MeCN]

PPh, in Me,CO

,

t

truns-[ReOC1,(PPh3),3 [MeCOCH,C(Me)2PPh,],[Re,C1,1,2Me,C0 Scheme 8

[ReOCI3(PPh,),] reacts with monobenzoylhydrazine to afford the ketone hydrazone complex ( 104),and other such derivatives have been characterized! 0 2 2 Mass spectrometric and molecular weight studies of trans-[ReCl,(acac),] have shown that it is monomeric and not dimeric as previously reported. ci~-[ReCl,(acac)~]has been isolated for the first time by evaporation of the filtrates of the trans- preparation. [ReO(OMe)X,(PPh,),] (X = Br or I) react

1079

lo''

J. E. Fergusson and D. E. Scaife, Inorg. Nuclear Chern. Letters, 1971,7,987: P. J. Cresswell, J. E. Fergusson, B. R. Penfold, and D. E. Scaife, J.C.S. Dalton, 1972, 254. M. L. Mehta, J . Mol. Spectroscopy, 1972,42, 208. H. Miiller and R. Waschinski, Inorg. Nuclear Chern. Letters, 1972,8,413. R. A. Walton, Inorg. Chern., 1971, 10, 2534.


173

with Hacac to form mainly cis-[ReBr,(acac),] and trans-[ReI,(acac),]. [ReCl,(dbm),] has also been prepared for the first time."*, K,[ReCl,] reacts with oxalic acid (1:4) in aqueous solution to give K,[Re,0(C,0,H2)(C20,),1,H,O. Similarly, K,[ReCl,] and KHphth (H,phth = phthalic acid) in HC1 solution form K,[Re20(Hphth),(OH)2C14]. These complexes appear to involve a

CR, (104)

Re-0-Re linkage."83 The complexing of rhenium(1v) with thiourea (L) has been studied in HCl solutions in the presence of tin(r1) by a cation-exchange method, and equilibrium stability constants p1--p4 for [ReOL,12+ + nC1[ReOCl,L,-,]2-" nL determined.loS4 The complexing of rhenium(1v) with thiocyanate ions in HC1 solutions in the presence of SnCl, has also been investigated and the formation of a 1: 1 ReIV-SCN- complex confirmed.1085 Technetium(v) and Rhenium(v) Complexes.-Re,Te, has been obtained by ampoule synthesis from the elements at 800 "C, and its thermodynamic constants and X-ray diffraction characteristics determined.loS6Re,S3Cl, has been identified in the Re-S-Cl system.' 07' Chloride complexes of technetium(v), K,[TcOCl,] and K,[TcO(OH)Cl,], have been obtained from a solution of KTcO, in HCl.loB7 A new method for the preparation of K,[ReO,(CN),] involves the treatment of [Re0,(py),]C1,2H20 with excess KCN for ca. 1 h in a warm, concentrated solution.'0B8The earlier report that K,[ReO,(CN),], [Re0,(en),]C1,2H20, and [Re0,(py),]C1,2H20 are eight-co-ordinate with Re(OH), moieties, has been shown to be incorrect. Spectral studies have established that these complexes have the trans-[ReO,L,] arrangement identified for K, [ReO,(CN),] in acrystallographic study. 'O S 9 The acid association constantsof [ReO,(CN),] have been determined and the violet colour obtained on acidifying a solution of anion has been shown to be due to [ReO(OH)(CN),12-. The mono- and di-basic acids H[ReO(OH)(H,O)(CN),] and H,[ReO(OH),(CN),] and some of their salts have also been isolated.'088 [Re02(CN),13- in acidic solutions

7

1082

1083 1084

1085 1086

1087 10x8

+

W. D. Courrier, C. J. L. Lock, and G. Turner, Canad. J . Chem., 1972,50, 1797. S . M. Basitova, F. Sh. Shodyev, and R. A. Egamberdyev, Doklady Akad. Nauk S.S.S.R., 1971, 14, 37. I. N. Marov, L. V. Boisova, E. I. Plastinina, and N. B. Kalinichenko, Zhur. neorg. Khim.,1971, 16, 1869. M. A. Mubayadzhan, Ref: Zhur. Khim. 1970, Abs. No. 17V132. A. A. Opalovski, V. E. Fedorov, B. G. Erenburg, E. U. Lobkov, Ya. V. Vasil'ev, L. N. Senchenko, and B. I. Tsikanovskii, Zhur. Jiz. Khim., 1971,45,2110. V. I. Spitsyn, M. I. Glinkina, and A. F. Kuzina, Doklady Akad. Nauk S.S.S.R., 1971,200, 1372. M. C. Chakravorti, J . Inorg. Nuclear Chem., 1972,34,893.

174


affords the anion [Re203(CN)8]4- (105), with the linear 0-Re-0-Re-0 system, and isotopic exchange between bridging and terminal 0x0-ligands and solvent molecules has been investigated.' 0 9 0 Further reports of the preparation375. 1091andafullaccount ofthecrystalstructure1092of[Re203(S,CNEt2),], which also involves a linear 0--Re-0-Re-0 moiety, have been published. N

N

I

C

O-Re-

I/

C/

N

0-Re-0

I

c

,N

I I

I

N

N (105)

The terminal Re-0 bonds in both these anions [169.8(7)and 172.2 pm, respectively] suggest that they are triple bonds, and the bridging Re-0 bonds [191.5(1) and 191.0pm, respectively] would appear to have a bond order between one and two. [Re,03(S2CNEt2),], dissolved in the minimum volume of CH,CI,, reacts with MeOH to form [ReO(OMe)(S,CNEt,),]; however, attempts to prepare the corresponding ethoxy-derivative have been unsuccessful.' 09' [Re,03(en),C1,] has been shown to contain a linear Re-0-Re unit, and almost linear 0-Re-0 moieties.'093 l80Tracer studies have shown that, when [ReO,(en),]+ is oxidized to [ReO,]- the trans-O=Re=O unit of the rhenium(v) is transferred essentially intact to the perrhenate The pink complex formed on addition of a three- to ten-fold excess of thioglycollic acid to perrhenate solutions in dilute H,SO, (pH 3 - 4 1 appears to be [ReO,(SCH,CO,H),]from electronic spectral and conductance studies,' 09sa and the complex (ROH,)[ReO(SCN),] may be extracted by isoamyl alcohol (ROH) from solutions of rhenium(v) and thiocyanate in aqueous HCl.'09sb The nitrogen Is binding energy in [ReNCl,(PPh,),] has been reported,lo4' and the details of the structural analysis of [ReN(S2CNEt,),] have been published. The square-pyramidal molecules of the latter complex (106) have the metal atom some 73 pm above the base of the pyramid, and a Retriple loa9

lo90

'Ogl

'Og3

log4 lo9$

R. K. Murmann and E. 0.Schlemper. Inorg. Chem., 1971,10,2352:R. H. Fenn, A. J. Graham, and N. P. Johnson, J . Chem. SOC. ( A ) , 1971, 2880: N. P. Johnson, J . Inorg. Nuclear Chem., 1972,34, 2875. R . Shandles, E. 0.Schlernper, and R. K. Murmann, Inorg. Chem., 1971,10,2785: D. L. Toppen, Diss. Abs. (B), 1971, 32, 1432. R. A. Walton and D. L. Wills, Synthetic Inorg. Metal-Org. Chem.. 1972, 2, 71. S. R. Fletcher and A. C. Skapski, J.C.S. Dalton, 1972, 1073. T. Glowiak. T. Lis, and B. Jezowska-Trzebiatowska, Proceedings of the Third Conference on Co-ordination Chemistry, 1971, 73. L. B. Kriege and R. K. Murmann. J . .4mer. Cheni. Soc.. 1972. 94.4557. ( a ) L. L. Talipova, E. L. Abramova, and N. A. Parpiev, C'zbek. khim. Zhur., 1971, 15, 2 3 ; (b) I. Pajak, Rudy Metale Niezelazne, 1971, 16, 299.


175

bond of length 165.6 [ReOCl,(PPh,),] reacts with mono- or dibenzoylhydrazine in benzene-ethanol solution in the presence of HCl to form (99). Other analogues [Re(N,COR')X,(PRi),] [Re(N,COPh)Cl,(PPh,),] (X = C1 or Br) have been isolated, and the rhenium 4f binding energies have been determined for several of these complexes.'042" The five-membered ring in these complexes is opened by several nucleophiles to give the corresponding rhenium(II1)benzoylazo-complex, and certain tertiary and ditertiary phosphines react further in alcoholic solvents to give rhenium(1)dinitrogen complexes.'022 N

I

(106)

Phosphinimines RN=PPh, (R = Ph or PhCO) react with rhenium oxocomplexes to form arylimido-derivatives, thus [ReOCl,(PPh,), j affords [Re(NR)CI,(PPh,),].762 An alternative preparative route to these complexes involves heating a suspension of the rhenium 0x0-complex in xylene with PhNCO or PhNH, under argon for 4 h, and trans-[Re(NPh)Cl,(PR,),] (R, = Ph, or Et,Ph) have been obtained in this manner.'097 (bipy)[R&l,] affords [ReCl,(bipy)] when heated at 230 "C, and the X-ray powder pattern of this complex has been reported.' 09* Technetium(v1) and Rhenium(v1) Complexes.-The thermal decomposition of [Re,(CO),,] in excess oxygen at 250--300°C is a new and efficient route to Re0,.1099 The reaction of rhenium metal with M O (M = Mg or Zn) has provided values of - 280 & 15 and - 875 8 kJ mol- for the heats of formation of ReO,(g) and Re,O,(g), respectively.' l o o Crystals of Ba,MReO, (M = Mg, ,Mn, Fe, Co, or Ni) have been prepared and their magnetic and electronic properties examined.' O' Direct chlorination of powdered technetium metal gives a blue product, not TcCI,; by reducing the amount of oxygen contamination the amount of blue material produced can be reduced but not eliminated. Chlorination of the metal on porous pot affords a green product which resembles 'TcCl,'. Both the blue and green products are, in fact, mixtures of purple TcOCl, and colourless TcOCI, and these compounds have been isolated pure by vacuum distilla-

*

'

'

S. R. Fletcher and A. C. Skapski, J.C.S. Dalton, 1972, 1079. I. S. Kolomnikov, Yu. D. Koreshkov, T. S. Lobeeva, and M. E. Vol'pin, Izuest. Akad. Nauk S.S.S.R., Ser. khim., 1971, 2065. lo9' V. M. Akimov, M. Romero de Endara, G. K. Babeshkina, V. M. Stepanovich, and V. P. Dolganev, Izvest. 1.: c'. Z . Khim.i khim. Tekhnol., 1970,14, 1835. P. Lemoine, J. Brenet, and M. Gross, Compt. rend., 1972,274, C , 1. ' l o o H. B. Skinner, Diss. Abs. (B), 1971.32,215. 1101 A. W. Sleight and J. F. Weiker, J . Phys. Chem. Solids, 1972,33, 679.

176


tion, and characterized for the first time.' O Z o A molecular-beam-mass-spectrometric study of ReOCl, vapour has shown that it consists primarily of monomeric molecules which have an ionization potential of 10.7 & 0.5 eV.'" The i.r. spectrum of ReOCl, in gaseous and condensed phases has been recorded.'102 In the former the v(Re=O) absorption occurs at 1040 cm-' and exhibits P,Q, and R branches. These data do not discriminate between square-pyramidal and trigonal-bipyramidal molecular geometries, although crystals of the compound have been shown by X-ray crystallography to involve square-pyramidal molecules with an apical oxygen atom, Re-0 = 163pm."03 This has been claimed to be consistent with the i.r. spectrum, and it was suggested that Re204Cl,, formed in the ReOC1,-Re0,Cl system (m.p. 38 "C), involves one octahedral rhenium with four chlorine atoms in a plane and trans-oxygen atoms, one of which links the metal to the other rhenium which is tetrahedrally co-ordinated to three oxygens and one chlorine.' l o 4 The hydrolysis of ReOCl, in CCl, has been followed by i.r. spectroscopy and the absorption at 1018 cm-' suggested to be characteristic of ReOC1,,H20.' lo' This compound has been obtained crystalline by reacting ReOC1, and H,O (1 : 1) at 350 "C for 24 h and its structure determine (107). The compound is stable in w c u o in the absence 0

I /c1

c1, c1/

p"\c1 H,O

(107)

o f a temperature gradient, and although insoluble in CCl, and TiCl,, it is slowly decomposed to give a green solution of ReOC1,.'105 Thus the i.r. characterization in CCl, may be incorrect. Three new compounds of rhenium(vI), ReOCl,(MeCN), [ReO(NH,),],, and (Ph,P)[ReOBr,], have been prepared by reacting ReOC1, with MeCN, anhydrous NH,, and Ph4PBr in anhydrous CHCl,, respectively. [ReO(NH,),], is only weakly paramagnetic and has a broad R e - 0 stretch at 830cm-', and thus appears to have a polymeric, 0x0-bridged structure.' l o 6 Technetium(vI1) and Rhenium(v1 I) Complexes.-New high-energy bands have been observed in the electronic absorption spectra ( 2185 nm) of [Tc04] and [Re0,]-.737 The reduction of [Re04]- to rhenium(1v) has been studied using a dropping mercury electrode, and the electron-transfer process was shown to be followed by disproportionation reactions involving H 2 0 with 1102

'lo3 ''O4

'lo5

'

lo6

C. G. Barraclough and D. J. Kew, Austral. J . Chem.. 1972,25,27. A. J. Edwards, J.C.S. Dalton, 1972,582. K. I. Petrov, V. V. Kravchenko, D. V. Drobot, and V. A. Aleksandrova, Zhur. neorg. Khim., 1971,16,1749: 2295. P. W. Frais and C. J. L. Lock, Canad. J . Chem., 1972, 50, 1811. D. A. Edwards and R. T. Ward, J.C.S. Dalton, 1972, 89.

177


evolution of H2.1107Th[ReO,], and Np[ReO,], have been prepared by the action of Re,O, vapour on the metal dioxide at high temperature in a sealed tube, or by the action of H[ReO,] on thorium(1v) or neptunium(1v) salts in aqueous media.'lo8 M,[ReO,] (M = Rb or Cs) have been obtained from solid-state reactions of M,O or MO, with Re02.'109 Equatorial and axial Re-F stretching force constants for ReF, have been calculated as 4.0 and 4.6 mdyn A - respectively, from a vibrational analysis of this molecule.' l o ReF, and ReOF, react with N O F and NO,F to form the salts (NO)[ReF,], (NO,)[ReF,], (NO)[ReOF,], and (NO,)[ReOF,]. The Raman spectra of the solids, and their "F n.m.r. spectra in anhydrous HF, confirm the ionic nature of the complexes and suggest that the [ReF,]- ion has D4d, and the [ReOF,]- ion C5v,symmetry."" ReS3C1, m.p. 63"C, and ReS,Cl,nS,Cl, ( n < 1) have been identified in the Re-S-Cl system.'075 The complexes [ReO,ClR,] (HR = 7-X-substituted 8-mercaptoquinoline, X = F, C1, Br, or I) have been prepared and characterized by their electronic absorption spectra.329

',

8 Appendix Reviews and texts relevant to the early transition elements which have not been referred to in the text include: 'The Early Transition Metals', D. L. Kepert, Academic Press, New York, 1972. 'Inorganic Chemistry', ed. H. J. EmelCus, M.T.P. Review of Science, Series One, Butterworths, London, 1972. 'Hydride Complexes of the Transition Metals', H. D. Kaesz and R. B. Saillant, Chem. Rev., 1972,72, 231. 'Inorganic Synthesis in Non-aqueous Solvents', B. L. Laube and C. D. Schmulbach, Progr. Znorg. Chem. 1971,14,65. 'Chemistry of double alkoxides of various elements', R. C . Mehrotra and A. Mehrotra, Znorg. Chim. Acta Rev., 1971,5, 127. 'Oxygenated Bronzes', P. Hagenmuller, Progr. Solid State Chem., 1971,5, 71. 'The Photochemistry of Transition-metal Co-ordination Compounds', W. L. Waltz and R. G. Sutherland, Chem. SOC.Rev., 1972,1,241. 'Single-crystal and Gas-phase Raman spectroscopy in Inorganic Chemistry', G. A. Ozin, Progr. Inorg. Chem., 1971,14, 173. 'Electronic Spectroscopy of High-temperature, Open-shell Polyatomic Molecules', D. M. Gruen, Progr. Inorg. Chem., 1971,14, 119. 'Vibrational Spectra of Intra- and Inter-metal and Semi-metal Bonds', E. Maslowsky,jun, Chem. Rev., 1971,71, 507. 'Metal-metal interactions in Transition-metal Complexes containing Infinite

'Io7

'lo' 1109 1110

1111

N

T. Ya. Rubinskaya and S. G. Mairanovskii, Electrokhimiya, 1971, 7, 1403. J. P.Silvestre, M. Pages, and W. Freundlich, Compt. rend., 1971,272, C, 1808. G.DUquenoy, Rev. Chim. minbrale, 1971.8. 683. G. P. Bhavsar and K. Sathiandan, Current Sci., 1972,41, 173. H.Selig and Z. Karpas, Zsrael J . Chem., 1971,9, 5 3 .


178

Chains of Metal Atoms’, T. W. Thomas and A. E. Underhill, Chem. SOC. Rev., 1972.1,99. ‘Metal-Metal Bonded Halogen Compounds of the Transition Metals’, J. E. Fergusson, Preparative Znorg. Reactions, 1971, 7,93. ‘Transition-metal Cluster Compounds’, R. B. King, Progr. Inorg. Chem., 1972, 15, 287. ‘Bonding in Metal Carbonyls’, P. S . Braterman, Structure and Bonding, 1972, 10, 57. ‘Nitrogen groups in Metal Carbonyl and Related Complexes’, M. Kilner, Ado. Organometallic Chem., 1972,10, 115. ‘Nitrogen fixation’, J. Chatt and G . J. Leigh, Chem. SOC. Rev.,1972,1, 121. The shorthand notation employed to summarize the physical properties reported for a particular compound is explained in Table A.

Table A S y m bo1 C

ch d e e.s.r. AH i.r. K m.p.

ms. m.w.

n.m.r. PO’ R S

st t.d. P

X

Shorthand notation f o r physical properties“ Physical propertyltechnique conductance (electrical properties) chromatography density electronic spectrum electron spin resonance spectrum heat of formation infrared spectrum formation constant melting point mass spectrum molecular weight nuclear magnetic resonance spectrum polarography Raman spectrum solubility molecular and/or crystal structure thermal gravimetric analysis, differential thermal analysis, or thermal decomposition magnetic moment at room temperature X-ray powder diffraction pattern and/or unit cell dimensions

(a) It has been assumed that all compounds reported have been characterized by elemental analysis.

2 Elements of the First Transitional Period BY R. DAVIS

1 Introduction In general, the format of this report i s similar to Volume 1, and only a few minor changes have been made. The systematic coverage of each metal has been reversed so that it is consistent with the other chapters. Thus low oxidation states are now considered first. It is felt, however, that unnecessary fragmentation occurs when such a converage is strictly applied. Therefore carbonyl, nitrosyl, and nitrogenyl compounds of each element are covered under individual headings. Secondly, the increased interest in some areas is reflected by the inclusion of some new sub-sections. These mainly reflect the growing number of publications related to the biological role of transition metals.

2 Manganese Carbonyl Compounds.-Two new transition-metal-manganese carbonyl compounds have been reported. Mn,M(CO),, (M = Ru or 0 s ) are formed by the reaction of Mn,(CO),, and M,(CO),, in a sealed tube at high temperature. Both compounds are assigned linear structures containing metal-metal bonds and terminal carbonyl groups only; uiz. (CO),MnM(CO),Mn(CO),.’ The i.r. spectra of the series of compounds [Mn,Fe(CO),,], [MnReFe(CO),,], and [Re,Fe(CO),,] have been examined in detail., The complexes trans-ML,Cl, (M = Pt or Pd; L = pyridine, 3- or 4-methylpyridine) react with [Mn(CO),]to yield trans-ML,[Mn(CO),],. The metal-metal stretching frequencies have been assigned and force constants calculated. Mn(CO),),] X-Ray structural determinations on [(2,2’:6’,2”-terpyridyl)Cd{ and [Hg(Mn(CO),},] have been reported. The former has distorted trigonalbipyramidal geometry at the cadmium atom and shows considerable distortion of the octahedral co-ordination around the manganese atoms, and the latter contains a linear Mn-Hg-Mn system, the Mn(CO), groups being eclipsed. The complexes [XnIn(Mn(CO),),-n] (X = C1 or Br; n = 0 - 2 ) have been prepared and studied in detail. The indium-manganese bonds are readily

E. W. Abel, R. A. N. McLean, and S . Moorhouse, Inorg. Nuclear Chem. Letters, 1971, 7, 587 G. 0. Evans and R. K . Sheline, Znorg. Chem., 1971,10, 1598. P. Braunstein and J. Dehand, J.C.S. Chem. Comm., 1972,164. W. Clegg and P. J. Wheatley, J.C.S. Chem. Comrn., 1972,760. W.Clegg and P. J . Wheatley, J. Chem. SOC.f A ) , 1971, 3572.

179

180

Inorganic Chemistry of the Transition EIements

cleaved by halogens or halogen acids to give either [XIn{ Mn(CO),),], [X,In{Mn(CO),)]. or InX, depending on the reaction conditions and stoicheiometries. In D M F solution all these compounds dissociate to [Mn(CO),]-, and in methanol or acetone [XIn(Mn(CO),},] and LX21n{Mn(CO),)] both undergo redistribution reactions to yield [In{ Mn(CO),},] and InX,. However, in acetonitrile the following equilibria are set up: [Tn(Mn(CO),; 3 ] = [In{Mn(CO),jz]' + [Mn(CO),][ X I n ~ M n ( C O ) , ] , ]=- [In(Mn(CO),j2]+ + X 2 [ X , I n ~ M n ( C O ) , ~ ]= [In[Mn(CO)S]2]f + InXS

Upon addition of perchlorate ions to the aceton'itrile solutions, the salt [(MeCN),In(Mn(CO),),]ClO, can be isolated. This will react with pyridine or phenanthroline to yield [L,In{Mn(CO),),]ClO, (L = py or phen). The (12 = 1-3; R = Me, X = C1; R = Et, compounds R,N[X,-,In(Mn(CO),],J X = Br) have also been prepared. Thus this work shows that as well as influencing the amount of dissociation of metal-metal bonded complexes, the nature of the solvent also determines the mode of ionization.6 The complex [TI{Mn(CO),3 ,] can be conveniently prepared from thallium(1) salts and .[Na! Mn(CO), >] The series of polysilane derivatives, [{(Me,Si)nSiMe, -n)Mn(CO),] ( n = 1-3) have been prepared by heating Mn,(CO),, and [(Me,Si)nSiMe,-nH] at 130'C in a sealed tube for 36 h.* H,Ge-Mn(CO), has been isolated from the reaction of GeH,Br and Na[Mn(CO),] in THF. The corresponding trideuterio-compound has also been prepared and extensive spectroscopic data have been reported.' In an attempt to prepare halogen-bridged Ge-Mn compounds, [Me,ClGeMn(CO),] was subjected to U.V. irradiation; however, the compound [(Me,Ge),Mn,(CO),1 was formed. l o The reaction of silyl halides with metal carbonyl anions is somewhat anomalous, as one of several reactions can occur: (a) formation of disiloxanes and polynuclear anions; (b)abstraction of hydrogen from the solvent: (c) oxidation to dimers, oligomers, or halogenated compounds. It was argued that increasing the nucleophilicity of the anion by phosphine substitution would possibly stop these anomalous reactions, but in the case of manganese this was not so. The corresponding reactions with germyl and tin halides are normal except that bulky substituents on the anion cause severe steric hindrance." Reaction of the compounds [Ph,MMn(CO),] ( M = Si. Ge. or Sn) with Ph,P gives [Ph,MMn(CO),(PPh,)] : with diphos or bipyridyl (L,). [Ph,MMn(CO),LJ is formed. However, the

' A . T. T. Hsieh and M. j . Mays. C h c m Covini.. 1971. 1134:J.C.S. D N ~ I O I1972. I . 516. - H. J. Haupt and F. Neumann. J . Uryanortirrollic. Cheni.. 1971. 33, C56. A. T. T. Hsieh and

Mays, J . Organometallic Chem., 1972. 38. 243. B. K. Nicholson and J. Simpson, J . Orgunometollic Chem.. 1971,32, C29. R D. George. K. M. Macka!-. and S. R . Stobart. J.C.S. Daltori, 1972, 1505. "' 11. D. Curtis and R . C . job, J . Amer. C'iiern. SOC.,1972. 94, 2153. ' ' M . D. Curtis, Inorg. Chem.. 1972, 11, 802.

M. J .

Elements of the First Transitional Period

181

reaction with phosphites, P(OR),, yields trans-[ RCOMn(CO), {P(OR),),].l Evidence suggests that the initial steps in the reaction are: +

Ph,MMn(CO),

+ P(OR), -+ Ph,M-P(OR), + [Mn(CO),]1 Ph,MPO(OR), + RMn(CO),

Treatment of Mn(CO),Br with NOPF, in acetonitrile yields the cationic complex [Mn(CO),(MeCN)]PF6,I3whereas reaction of trans-[Mn(CO),L,Br] (L = PhMe,P or PhMe,As) or cis-[Mn(CO),L,Br] (L = PhMe,As or L, = Ph,PCH,CH,PPh,) with NOPF, in benzene gives fac-[Mn(CO),L,Br]PF,.14 This last-named series of compounds is unusual in that they are carbonyl compounds of Mn". The crystal structure of [Ni(l,lO-phen),] [Mn(CO),], has been reported. The anions are trigonal-bipyramidal with only very small distortions. I s The reactions of [Mn(CO),]- with M,(CO),, (M = Fe, Ru, or 0 s ) are extremely complex and very dependent on the conditions employed, and only Me,N[MnOs,(CO), ,] could be isolated in an analytically pure state. Acidification of these complex mixtures leads to a series of hydrido-complexes, some of which have been reported previously. New hydrides isolated include [HMnOs,(CO),,], [HMnOs,(CO), ,I, and [H3MnOs3(CO),3].16 The reaction of [(n-C,H,)Mn(CO), - ,(CS), - ,(cycle-octene)] with CS, gives good yields of [(n-C,H,)Mn(CO), -x(CS)x] when x = 1 and 2, and small yields of the trithiocarbonyl complex.' The organo-lanthanons, (MeC,H,),Sm, (C,H,),Er, and (C,H,),Yb act as Lewis acids towards [(n-MeC,H,)Mn(CO),], by co-ordinating to carbonyl oxygen atoms and thereby producing a lowering of the C-0 stretching frequency." The Lewis acids AlX,, FeCl,, and SbCl, form adducts with Mn(CO),X (X = Cl, Br, or I); however, in this case co-ordination is to the halogen atom of the metal carbonyl species. 1:l and 1:2 (metal carbonyl halide: Lewis acid) complexes have been observed.' [Mn,(CO),(PH,)] has been prepared by the reaction between Mn,(CO),, and PH, in hexane-benzene under U.V.irradiation. 1.r. evidence indicates that the phosphine ligand is equatorial.20 The reaction between Mn,(CO), and PPh, has been re-investigated under a variety of conditions.21 Both monoand di-nuclear products have been isolated and. by carrying out the react ion

,

l2

23

l4 l5

l6 l7

l9

2o

E. P. Ross, R. T. Jernigan, and G. R. Dobson, J . Inorg. Nuclear Chem., 1971, 33, 3375. N. G. Connelly and J. D. Davies, 1 . Organometallic Chem., 1972, 38, 385. R. H. Reimann and E. Singleton, J . Organometallic Chem., 1971, 32, C44. B. A. Frenz and J. A. Ibers, Inorg. Chem., 1972, 11, 1109. J. Knight and M. J. Mays, J.C.S. Dalton, 1972, 1022. A. E. Fenster and I. S . Butler, Canad. J . Chem., 1972, 50, 598. A. E. Crease and P. Legzdins, J.C.S. Chem. Comm., 1972, 268. M. Pankowski, B. Demerseman, G . Bouquet, and M. Bigorgne, J . Organometallic Chem., 1972, 35, 155. E. 0. Fischer and W. A. Herrmann, Chem. Ber., 1972,105,286. J. R. Miller and D. H. Myers, Inorg. Chim. Acta, 1971, 5 , 215.


182

in an e.s.r. cacity, paramagnetic products have been verified but not isolated. The mononuclear product isolated is diamagnetic and is believed to be [HMn(CO),(PPh,)]. The following mechanism has been suggested for the reaction : [Mn,(CO),(PPh,)] + CO [(9:10)-Mn,(CO),(PPh,),] + CO [Mn2(Co)&PPh3),] + [HI [HMn(CO),(PPh,)] + [Mn(CO),(PPh,)] [Mn(CO),(PPh,)] + [HI -+ [HMn(CO),(PPh,)] [HMn(CO),(PPh,),] + CO [HMn(CO),(PPh,)] + PPh, ([HI = hydrogen abstracted from the solvent or PPh,.) Mn,iCO),, + PPh, [Mn,(CO),(PPh,)]

-+

+ PPh,

-+

-+

--f

Treatment of Mn,(CO),, with the diphosphines Ph,P(CH,),PPh, (dpe) or Ph,PCH,PPh, (dpm) gives the previously reported [Mn(CO),(dpe)] and [Mn(CO)(dpe),] and the new dimeric species [Mn(CO),L,], (L, = dpe or dpm). The latter are thought to contain bridging phosphine ligands. The complex [Mn(CO),L2Mn(CO),] (L, = dpm) is also reported, and this reacts with bromine at 0 'C to yield [Br(CO),MnL,Mn(CO),Br]. The reaction of Mn(CO),Br with the phosphines to yield Mn(CO)(L,),Br proceeds under relatively mild conditions., The phosphino-silane ( 1) reacts with Mn,(CO), at 50-C in benzene to give ( 2 ) . 2 3 The co-ordinating ability of a series of new phosphines has been studied The results of these extensive studies are given i n Table 1. by King et

a c H 2 - S i MI e 2 /Mn(CO),

~ J . v . irradiation of [(K-C,H,)M~(CO),]and R,NPF, [R = Me or C,H,, (C,H,,,N = N-piperidino)] gives yellow [(IT-C,H,)M~(CO)(PF,NR,),~.~~ The related complex [(K-C,H,)M~(CO),(PP~(NE~,),}] reacts with HX to give [(rr-C,H,)Mn(CO),(PPhX,)] (X = C1, Br, or I) and with several fluorinating agents to give [(Tc-C,H,)Mn(C0)2 [PPhF(NEt,))] and [(n-C,H,)Mn(CO)Z( PPhF ,)I ., The compounds [( TC-CH,)Mn( CO),( PH ,)I and [(T~-C,H,)Mn(CO),(PPhH,)] have been prepared by the reaction :,'

,

22

23

i5 26 27

''

29

R. H.Reimann a n d E. Singleton, J. Orgariometallic Chrm., 1Y72, 38, 113. H. G. Anp a n d P. T. Lau. J. Orgarionierallic Chem.. 1972, 37, C4. R. B . King and P. N. Kapoor. Inorg. Ctzem., 1971. 10. 1841. R. B. King, R . N. Kapoor, M . S. Saran, a n d P. N. Kapoor, Iiiorg. Chem.. 1971, 10, 1851. R. B. King and M. S. Saran. inorg. Chem.. 1971, 10. 1861. R. B. King, W . C . Zipperer, a n d M. Ishaq. inorg. Cltem., 1972. 11, 1361. M . Hofler a n d M . Schnitzler, Chem. Ber.. 1972, 105, 1133. M . Hofler and M . Schnitzler, Chem. Ber.. 1971, 104, 3117.

Elements of the First Transitional Period [(n-C,H,)Mn(CO),(PPhnC13 -J] + (3

-

n)NaBH,

183

Tx

[(n-C,H,)Mn(CO),(PPh"H,_n)]

Table 1

(n = I or 0).

Reactions of manganese carbon?,/ compounds with pnIwydc~tiiute pli osphines Mode of'

Reactants MeMn(CO), Mn(CO),Br [(n-Cp)Mn(CO),NO]+

Pf.Pf.Pf Pf.Pf.Pf Pf.Pf.Pf

MeMn(CO), Mn(CO),Br [(n-Cp)Mn(CO),NO]+

Pf.Pf.Pf.Pf Pf.Pf.Pf.Pf Pf.Pf.Pf.Pf

Products [MeMn(CO),(Pf.Pf.Pf)] [Mn(CO),(Pf.Pf.Pf)Br] [(n-Cp),Mn,(CO)(NO),(Pf.Pf.Pf)]2 [MeMn(CO),(Pf.Pf.Pf.Pf) [Mn(CO),(Pf.Pf.Pf.PfBr] [(n-Cp),Mn,(CO)(NO),(Pf.Pf.Pf.Pf)]2

bonding bidentate terdentate terdentatebridging bidentate terdentate terdentatebridging

either [MeMn(CO),{P(Pf),}] or [Mn(CO),(COMe){P(Pf),}] [Mn(CO),{P(Pf),}Br] [(n-CP)Mn(No){P(Pf),}l+

terdentate bidentate terdentate quadidentate

+

+

MeMn(CO),

P(Pf),

Mn(CO),Br [(n-CP)Mn(Co),(No)l+

Wf),

MeMn(CO),

P,(Pf),

(n-Cp)Mn(CO),

P,(Pfj4

[(n-Cp)Mn(CO),NO]

+

P(Pf),

'z('f)4

either [{ P2(Pfl,}{ Mn(CO),Me},] sexidentatebridging or [MeMn(CO),{P,(Pf),}] terdentate or [Mn(CO),(COMe){P,(Pf),}] bidentate [Mn,(CO),(x-Cp),(P,(Pf),)l terdentatebridging [{ P,(Pf)4}Mn,(cO)(NO),terdentp-te(n-Cp),I2+ bridging

Pf.Pf.Pf = [(C6H5),PCH,CH,],PC6H, Pf.Pf.Pf.Pf = (C6H5),PCH,CH,P(C,H,)CH~CH2P(C6H5)CH2CH2P(C6H5)2 P(Pf), = [(C,H,),PCH,CH,I,P P2(PQ4 = [(C6H5),PCH,CH,],PCHzCI~,P[CH2CH~P(C,H,)2]~

The reaction of PhP(CH2CH2PPh2),(PfPfPf)with Mn(CO),Br is reported by Schneider et a!. to yield [Mn(CO),(PPfPf)Br] in which the phosphine is bidentate. The product was a mixture of two isomers which could not be separated on the preparative scale, although reaction of the mixture with Cr(CO),(THF) gave two readily separable products. Both are formulated as [Br(CO),Mn(PfPfPf)Cr(CO)5]. The structure (3) of one isomer has been determined: the phenyl group on P2 and the bromine atom are mutually trans, and it is suggested that the other isomer has these two entities in mutually cis positions and that this factor also gives rise to the two isomers of the original manganese c ~ m p o u n d . ~ ' 30

M.L. Schneider, N. J. Coville, and I. S. Butler, J . C . S . Chem. Comm., 1972, 799.

lnorgnnic Chemistry of the Transition Elements

184

Mn,(CO),, reacts u7ith f,fars (Me,As * C=CAsMe,CF,&F,) under U.V. irradiation in acetone to yield [Mn,(CO),(f,fars)] (4).The Mn-Mn bond length is 2.971(3)A, and the complex reacts with iodine to yield [(f,fars)(Mn(CO),I) ,I. structural studies on which indicate that there is no Mn-Mn bond. In refluxing xylene, f4fars reacts with Mn,(CO),, to form [(f4fars)Mn,(CO),], two isomers of which have been ~ b t a i n e d . ~ '

The cyclic arsine (AsMe), reacts with Mn,(CO),, at room temperature in daylight togive [Mn,(CO),(AsMe),] and at high temperature to give [Mn(CO),(AsMe),],: structures ( 5 ) and (6) are proposed in which the metal-metal bond is replaced by bridging arsenic atoms3' The crystal structure of [(CO),M~ASM~,C~(CO has ) ~been ] reported. The arsenic atom bridges the two As As As/As\

I

As

I

I

I

As

I

3i

32

I

-AS

AS

R. Cullen. F. L. Hou. L. Y . Y . Chan. and F. W. B. Einstein, Chem. Cotnm., 1971, 1229. P. S . Elmes a n d B. 0. West. J . Orgarinnierallic Chmi.. 1971. 32, 365.

J . P . Crow. W.


185

metal-pentacarbonyl moieties, the two metal-arsenic distances being almost identical., (n-ring)Mn(CO), (n-ring = n-Cp or n-MeCp) react with 1,2-ethylenebis(dipheny1arsine) (dae) and either 1,4-butylenebis(diphenylarsine)(dab) or its phosphine analogue (dpb) under U.V.irradiation in benzene or cyclohexane to yield [(n-ring)Mn(CO)(dae)] and [((n-ring)Mn(CO),),L] (L = dab or d ~ b ) .The , ~ ligands PhCH,EMe, (E = P or As), on reaction with MeMn(CO),, form [MeMn(CO),L,] and with Mn(CO),Br form [Mn(CO),L,Br]. Both pairs of complexes contain mutually trans donor ligands.,, Quantum yields have been reported for the reaction of Mn(CO),NO with nucleophiles such as Ph,P, Ph,As, and Bu,P.,~ The complexes [(n-C,H,)Mn(CO),L] [L = (R,O)E, R = Me, Et, Bu, or Ph; E = As or Sb] have been prepared, and their i.r. spectra compared with those of the corresponding (RO),P complexes. The orders of decreasing electron density at the metal atom, Sb(OR), 3 P(OR), > As(OR), and E(OAlkyl), > E(OAryl),, E = P, As, or Sb) are ~uggested.~' The reaction of Mn(CO), Br with [R2NC(R')NR2]Li gibes the carbamoyl complexes (7), the reaction probably preceeding via nucleophilic attack at a

co, co' (7) a; R1 = R2 = P h b; R' = Ph, R2 = p-tolyl c; R' = Me, R2 = Ph d ; R' = Ph, R2 = H

carbonyl group. Pyrolysis (7a) or U.V. irradiation (7a or b) of these compounds gives (8), for which a structure containing a delocalized n-system (i.e.pseudo-.nallyl) is suggested. Attempts to reverse the decarbonylation reaction with CO

33

34 35 36 37

H. Vahrenkamp, Chem. Ber., 1972,105, 1486. S. S. Sandhu and A. K. Mehta, Inorg. Nuclear Chem. Letters, 1971, 7, 891. R. L. Bennett. M. I. Bruce, and F. G. A. Stone, J . Organometallic Chem., 1972,38, 325. D. P. Keeton and F. Basolo, Znorg. Chirn. Acta, 1972,6, 33. T. B. Brill, J. Organometallic Chem., 1972, 40, 373.

186


at high temperature and pressure led to the formation of [Mn(CO),(NPhCPhNPh), not (7a).38In liquid ammonia, Mn(CO),CI, [Mn(CO),(PPh,)Cl],

and[Mn(CO),(PPh3),]C1formcis-[Mn(CO),(NH3)(CONH2)],cis-[Mn~CO),-

,

(PPh 3)( N H 3)( C0N H )] , and cis-[M n(C0),(P Ph ,), (C0N H ,)I, respectively. These products readily lose the elements of water in liquid ammonia to give [Mn(CO),(NH,),CN] and ~Mn(CO),(PPh,)(NH3)CN].39 Farona and Kraus have postulated the existence of both 0-and n-bonded dinitrile complexes of manganese carbonyl halides and suggest that the monomeric rc-complexes are the kinetically favoured species, whereas the a-bonded complexek are thermodynamically favoured." Spectroscopic and chemical evidence and conductivity measurements indicate that the reactions between SO, and'Mn(CO),R (R = alkyl or aryl) proceed cia the 0-bonded sulphinate which then rearranges to the thermodynamically more stable s-bonded isomer.' Manganese-2-alkynyl complexes react with liquid SO, to give the corresponding vinyl compounds containing a sultine ring, Mn--~=C(R)--S(O)-O-~H,. Thus the compounds [Mn(CO),(C,H,RSO,)] ( R = H or Me) have been prepared which lose SO, on heating or treating with alumina to generate the parent alkynyl~.'~ MeCo-COCI reacts with NaMn(CO), in T H F at 0 ^ Cto give Me-CO. CO Mn(CO), (33 Yo yield). The product is stable. but could not be isolated from the carbonylation of MeCO Mn(CO), at 80'C and high pressure of carbon monoxide. suggesting that such a compound is not an intermediate in reactions of MeCO * Mn(C0),.43 (R,PSS)Mn(CO), (R = Et or Ph) eliminates CO when warmed under high vacuum to yield [(R,PSS)Mn(C0)3]2.Under high pressure of C O the reverse reaction takes place and the dimer reacts with the donor Iigands, py or Ph,P(L), to give [( R2PSS)Mn(CO),L].44 Mn,(CO),, reacts with (CF,),S, under U.V. irradiation to yield [M n(CO),SCF ,] 2.45 The structure of the corresponding compound [Mn(CO),SeCF,], has been reported. It contains a planar (MnSe), unit wi'th four almost equal Mn-Se bond lengths (2.50A); other dimensions include Mn...Mn = 3.74& LSe= 96.9".46 CS, reacts with cis-[HMnMn--Se = 83.1 LMn-Se-Mn (CO),L] rL = 1,2-bisdiphenylphosphino-ethaneor -methane) at room temperature by hydridometallation of the CS bond forming a Mn-S-C(S)-H linkage."

38 39

4o

*' 42

43 44

45 46

''

T. Inglis. M .Kilner. and T. Reynoldson. J . C . S . Chem. Comm.. 1972, 774. H. Brhrens. E. Lindner. D. Maertens, P. Wild, and R.-J. Lampe, J . Organornetallic Chem., 1972, 34. 367. M. F . Farona a n d K . F. Kraus, J . C . S . Chem. Cotnm., 1972, 513. S. E. Jacobson, P. Reich-Rohrwig. a n d A . Wojicki, Chem. Comm., 1971, 1526. J. E. Thomasson, P. W. Robinson, D. A . Ross, a n d A. Wojicki. Inorg. Chem.. 1971, 10, 2130. C. P. Casey and C . A . Bunnell. J . Amer. Chem. Soc.. 1971, 93, 4077. E. Lindner a n d K. Matejcek, J. Orgartometallic Chem.. 1972, 34, 195. J. L. Davidson and D. W. A . Sharp, J.C.S. Dalton. 1972, 107. C. J . Marsden and G. M . Sheldrick, J . Organornetallic Chem., 1972,40, 175. F. W. B. Einstein. E. Enwall. N. Flitcroft. and J. M. Leach. J . Inorg. Nuclear Chern., 1972. 34, 885.


187

A complete study of the crystal structure of [Mn(CO),(C,PPh,)Br] has been published48 (see Vol. 1, p. 134).The reaction of 2-methyl- or 2,3-dimethyl2,3,4-tricarbahexaborane with Mn,(CO), in the gas phase yields the volatile n-complexes [(n-2-MeC,B3H,)Mn(C0)J and [(x-2,3-diMeC3B,H,)Mn(CO),]. The o-bonded complex, [(a-2MeC3B3H,)Mn(CO),] can be prepared from the sodium salt of the carborane and Mn(CO),Br, and this loses CO at 100"C giving the complex.^^ Photolysis of (n-C,H,)Mn(CO), or (n-MeC,H,)Mn(CO), with an unfiltered mercury lamp in a matrix at 175 K gave rise to new i.r. bands which were assigned to the species (7c-ring)Mn(C0),.50 The electronic spectra of the series of compounds LMn(CO), (L = CF,, Me, Cl, Br, or I) in the region 500&1900 8, have been recorded both in solution and in the vapour phase. Band assignments were made on the basis of qualitative M O diagrams.,' The preparation of ',Mn labelled IMn(CO), and HMn(CO), has been achieved by neutron bombardment of the unlabelled compounds. A 20 % yield of 56Mn in IMn(CO), was obtained.,' [(n-ring)Mn(CO),CN] (n-ring = n-C,H, or n-mesitylene) both appear to protonate at the nitrile nitrogen atom in aqueous solution: however, attempted isolation of the cation as the BF; salt led to formation of [(n-ring)Mn(CO),(CNBF,)]. However, Et,O+ and Ph,C+ form the complex salts [(n-mesityiene)Mn(CO),CN R]PF6 (R = Et or Ph3C).,, The optically active complexes (+)- and (-)-[(n-Cp)Mn(CO,Me)(NO)(PPh,)] can be prepared by transesterification of the diastereoisomeric menthyl esters or by methoxide attack on the cations (+)- and ( -)-[(n-Cp)Mn(CO)(NO)PPh,] +. Kinetic measurements indicate that the rate-determining step for racemization is dissociation of PPh,.,,

Nitrogenyl and Nitrosyl Compounds. -[(IT-Cp)Mn(CO),N,H,] is oxidized by treatment with hydrogen peroxide and Cu2+ ions in THF at -40°C for one hour forming [(n-Cp)Mn(CO),N,] as red-brown crystals. The complex is diamagnetic and v(NN) = 2169 cm-' in hexane. This is the first example of a nitrogenyl complex formed by oxidation of a hydrazine complex.55 [(n-Cp)Mn(CO),N,] liberates nitrogen from a T H F solution at room temperature, forming [(n-Cp)Mn(CO),(THF)]. However, the reaction does not proceed to completion and treatment of the T H F complex with N, regenerates the nitrogenyl complex.56 [(n-Cp)Mn(NO)(CO),]PF, reacts with Na' SCMe; and CS, in acetone to give the dark-green [(n-Cp)Mn(NO)S,CSCMe,]. The corresponding

48 49

50 51

52

53 54 55

56

S. Z . Goldberg, E. N. Duesler, and K. N. Raymond, Inorg. Chem., 1972, 11, 1397 J. W. Howard and R. W. Grimes, Znorg. Chem., 1972, 11,263. P. S. Braterman and J. D. Black, J. Organometallic Chem., 1972, 39, C3. G. B. Blackney and W. F. Allen, Znorg. Chem., 1971, 10, 2763. S. C. Srinivasan and D. R. Wiles, Chem. Comm., 1971, 1633. P. J. C . Walker and R. J. Mawby, J . Chem. SOC. ( A ) , 1971, 3006. H. Brunner and H. D. Schindler, Z . Nuturforsch., 197i, 26b, 1220. D. Sellmann, Angew. Chem. Internat. Edn., 1971, 10, 919. D. Sellmann, Angew. Chem. Internat. Edn., 1972, 11, 534.


188

complexes with the ligands S,CSCH,CHMe,, S,CSCHMe,, and S,CSCH,CH,Me can be prepared in a similar manner. However, in the absence of CS, in THF solution, the dimeric species [(n-Cp)Mn(NO)(SR)], and [((n-Cp)Mn(NO)(SR)),]PF, (R = CMe,, CH,CHMe,, or CHMe,) are formed. The monomeric compound undersoes a one-electron reversible oxidation. whereas the neutral dimer undergoes two one-electron oxidations. Voltammetric data have also been reported for [(n-Cp)Mn(NO)L,]' [L = CO, P(OPh),, PPh,, PPhMe,. 4-Mepy and L, = bipy]: the results were correlated with the charge on the complex and with the N O stretching frequency." The structure of [(n-Cp),Mn,(NO),(NO,)] has been reported. The dimer contains highly unsymmetrical bridging NO groups and a linear terminal N O group (9). The authors suggest that the structure of [(~c-cp),Mn,(NO),], about which there 0

0

\

/

/

N'

\

has been much controversy, is similar to (9) with the NO, group being replaced by a cyclopentadienyl ring.58 Other Manganese(1) Complexes.-[(n -Cp)Mn(CO),] reacts with PF, in THF under U.V. irradiation to give a 70 % yield of [ ( R - C ~ ) M ~ ( P F , ) Electro,].~~ chemical studies on [Mn(CNR),]PF, (R = Me. C,H,OMe, C,H,Me. C,H5, or C,H,Cl) indicate that all show two one-electron oxidations; however, the methyl complex is much easier to oxidize than any of the corresponding aryls." Manganese( 11). -Halides mid Pseudohalides. Fluoride complexes o f Mn" have been studied with a fluoride-ion selective electrode. The weak complex [MnF(aq)]+ was detected.61Magnetic properties of BaMnF, and Pb,MnF, have been reported.62 The structure of CsMnBr, consists of octahedrally co-ordinated manganese atoms with a trigonal distortion. The octahedra share opposite faces to form chains of composition (MnBr,):-.63 Cs,MnBr, contains tetrahedral anions.64 The complexes D,MnX, (X = C1 or Br; D = 2,4-dimethyl-l H-1.5-benzodiazepinium cation) have beeh prepared: the cation 57

58

59

6o 61

'' 63 64

P. Hydes, J . A. McCleverty. and D. G . Orchard. J . Chem. Soc. ( A , ) , 1971, 3660. J. L. Calderson. F. A. Cotton. B. G. DeBoer, and N. Martinez. Chem. Comm., 1971, 1476. T. Ktuck and V. Krause, Z . Naturjorsch., 1972, 27b, 302. P. M . Treichel and G . E. Dirreen. J . Orgattometallic Chem.. 1972, 39. C20. A. M. Bond and G. Hefter. J . Inorg. Nuclear Chem.. 1972. 34. 603. A. Chretien and M. Samoue, Monatsh., 1972, 103, 17. J. Goodyear and D. J . Kennedy, Acta Crvsr.. 1972, B28, 1640. J. Goodyear. G . A. Steipmann, and D. J. Kennedy, Acta Crysf.. 1972, B28, 1231.


189

D is not co-ordinated to the metal atom.65The MgC1,-MnC1,-H,O system has been studied, the double salts 2MgC12,MnC1,,12H20, MnC1,,MgCl2,8H2O, and MgC12,2MnC1,,12H,0 being formed.,, 1.r. and Raman data have been reported for (MeNH,)MnCl,, CsMnC1,,2H20, and C S M ~ C ~ , , ~ D , O . ~ ~ The crystal structure of Mn2[Ru(CN),],8H,0 has been determined. The ruthenium atom is surrounded by six cyanide groups in a slightly distorted octahedral array and all the cyanide groups are bonded via their nitrogen atoms to manganese. All the manganese atoms are bonded to three nitrogen atoms and three water molecules and two manganese octahedra are linked to form dinuclear Mn,N,(H,O), units sharing one edge.68 The electronic spectra of the Mn"-NCS-H,O system have been in~estigated.,~ Complexes. N-Donor Ligands. The reaction of manganese and the respective alkali metal in liquid ammonia yields the amide complexes M,Mn(NH,), (M = Na, K, Rb, or Cs)." The preparation of [Mn(3-Etpy),(H,O),]I, has been r e p ~ r t e d . ~The ' Mn" complex of 2,6-(dibenzothiazol-2-yl)pyridine(lo), [Mn(NNN)CI,], has

been isolated. It may be either five- or ~ix-co-ordinate.~~ The 2-pyridone (L) complex [MnL,(NO,),] has also been reported.73 MnX, (X = C10, or BF,) reacts with 2-methylimidazole in ethanoltriethylorthoformate to form the complexes [MnLnX2] ( n = 4 or 6). Both types of complex have distorted octahedral stereo~hemistry.~~ Similar complexes have been reported with N-n-butylimidazole, [MnLnX2] ( n = 1-6; X = C1, Br, I, or NCS). They are prepared in an analogous fashion and are pseudo-octahedral, the ligand being co-ordinated via the pyridine nitrogen of the five-membered ring.75 Pyrazole and 3(5)-methylpyrazole (L) react with manganese(r1) nitrate and thiocyanate to form complexes of stoicheiometry [MnL,X,], which have trans-octahedral s t r ~ c t u r e sThe . ~ ~ structure of [Mn(5methylpyrazole),Br,] has been confirmed by crystallography. The ligand is 65

66

67 68

69

70 71

72 73 74

75 76

P. W . W. Hunter and G . A. Webb, J . Inorg. Nuclear Chem., 1972,34, 1511. B. I. Zhelnin and G. 1. Gorshtein, Rum. J. Inorg. Chem., 1971, 16, 1666. D. M. Adams and D. C. Newton, J . Chem. SOC.( A ) , 1971,3449. M. Riiegg, A. Ludi, and K. Rieder, Inorg. Chem., 1971, 10, 1772. A. Lodzinska and F. Golinska, Rocznicki Chem., 1972,46, 155. J. Rouxel and P. Chevalier, Bull. SOC. chim. France, 1972, 11 1. M. Goodgame and P. J. Hayward, J . Chem. SOC.( A ) , 1971, 3406. S . E. Livingstone and J. D. Nolan, J.C.S. Dalton, 1972, 218. J. Reedijk and J . A. Smit, Rec. Trav. chim., 1972, 91, 681. J. Reedijk, Rec. Trav. chim., 1972, 91, 507. J. Reedijk, Rec. Trav. chim., 1971,90, 1249. J. Reedijk and J. A. Smit, Rec. Trav. chim., 1971, 90,1135.

I90

Inorganic c.'hemistry of the Transition Elements

co-ordinated via N 1 . 7 7E.s.r. studies on MnL,X, [L = pyrazole or 3(5)methylpyrazole: X = C1, Br, I, or NO,] have been interpreted in terms of slightly distorted D,, symmetry for the complexes.78 The 1,1,4-trimethylpiperaziniumcation ( 1 1) forms complexes of the type

(11)

[MX,L] (M = Co", Nil', or Cu"; X = Cl, Br, or I); however, in the case of manganese, (L'j2[MnX,] - (X = C1, Br, or I) was isolated and, in the presence of traces of water, protonation occurred at the nitrogen atom of (11) and (LH)'+ [MnX,]'- was formed.79 Manganese phthalocyanine (MnPc) can be reduced by Li in T H F in the presence of stilbene in five steps.80 The compounds Lin[MnPc),xTHF (n = 1. x = 6 ; n = 2, x = 6; n = 3. .Y = 9: n = 4, x = 10; n = 5, x = 9) were isolated. 0-Donor ligands. The reaction of hydrated MnX, salts (X = CIO,, BF,, or NO,) with trimethylorthoformate led to the isolation of the complexes [Mn(MeOH),]X2.8' The thermal decomposition of MnBr,,n(dioxan) ( n = 1 or 2) has been investigated: both ultimately decompose to MnBr,. The crystalline complex MBr,.2(dioxan).4H20 was isolated for M = Ni and Co, but not in the case of manganese.82 Mn(acac), reacts with ethylenediamine (L,) or other primary amines (L) to yield [Mn"(acac),L,], which can also be prepared by the reaction of the amine or diamine with [Mn(acac),(H,O),]. Allylamine reacts with [Mn(acac),(H20)2] in ether to give a second complex, [Mn(acac),(H,NCH,=CH,)], which is dimeric both in the solid and vapour phases. This is the first example of a dinuclear manganese(i1) acetylacetonate complex.83 Thermodynamic data have been reported for the manganese(I1)-acetylacetone system in propan-l~I-water.~~ Manganese@) forms the 3-ketoglutarate, MnA,xH,O. where A represents the anion in its dinegative form, [0,CCH,COCH,C02]2-. The hydration number is certain, but it is suggested that the anion is co-ordinated by a unidentate carboxylate The high-spin compound Mn(Pg), (Pg = '7

79 8o

" " 83

84

''

J. Reedijk. B. A. Stork-Blaisde, and G. C . Verschoor, Inorg. Chem., 1971, 10, 2594. R. D. Dowsing, B . Nieuwenhuijse, and J. Reedijk, Inorg. Chim. Acta, 1971,5, 301. A. S. N. Murthy, J. V. Quagliano, and L. M. Vallarino, Inorg. Chim. Acta, 1972, 6,49. R . Tanbe, H. Munke. and j. Petersen. Z . onorg. C/ILWI,, 1972, 390, 257. A. D. Van Ingen Schenau, W. L. Groeneveid, and J . Reedijk, Rec. Trav. chim., 1972, 91,88. .i. C . Barnes and C. S. Duncan, J . C . S . Dalton. 1972, 923. Y. Nishikaaa. Y. Nakamura. and S. Kawaguchi, Bull. Chem. SOC.Japan, 1972,45, 155; S. Koda, S. Ooi, H. Kuroya. Y. Nishikawa, Y . Nakamura. and S . Kawaguchi, Inorg. Nuclear Chem. Lerters. 1972. 8, 89. A. Dadgar and R. Delorenzo, J . Inorg. Nuclear Chem.. 1971,33,4155. F. W. Yerhoff and D. W. Larson. Canad. J . Chem., 1972,50, 826.


191

phenylglycollate) can be prepared from the action of phenylglycollic acid on Mn(OAc), in methanol. The compound is almost insoluble in water and organic solvent^.^ A rapid method of preparation of [Mn(NH,OH),Cl,] has been reported that is easily carried out and does not require the use of hydroxylamine. It involves treatment of manganese(I1) carbonate with hydroxylamine hydrochloride in boiling The complexes formed between Mn" and tetramethyl- and tetraethyl-dithio-oxamide have been investigated by the Job method: MnL,X, (X = ClO, or FeCl;) were observed.88 The preparation of [Mn(DMSO),(NCS),] has been reported,89 as have i.r. data for the ion [Mn(TMS0),I2+ (TMSO = tetramethylenesulphoxide). The spectrum of the latter is very similar to that of the DMSO analogue." The complexes [MnX,(DTMSO)n] (DTMSO = 1,4-dithiane monosulphoxide: X = C1, Br, I, NO,, or NCS; n = 2,3, or 6 ) have been isolated. The sulphoxide ligand is 0-bonded and all complexes contain co-ordinated anions except [Mn(DTMSO),]I,.9' The complex Mn(Ph,PO),(BF,), has been isolated and a square-pyramidal geometry is suggested, with a co-ordinated BF, ion.92In view of the increasing number of suggestions of co-ordinated BF, and PF, appearing in the literature, crystallographic determination of the structure of such compounds would be most welcome. The structure of the salt [MnI(Ph,PO),] [MnI,(CO),] has been reported. The cation is square-pyramidal with the iodine atom in the axial position.93 The reactions of 1,2,5-triphenylphosphole and its oxide, sulphide, and selenide with manganese@) halides have been studied.94 The ligands hexamethylphosphoramide (HMPA) and nonamethylimidodiphosphoramide (NIPA) react with Mn(C10,), to give tetrahedral Mn(HMPA),(CIO,), and octahedral Mn(NIPA),(ClO,),, re~pectively.~' Phenylbis(dimethy1amino)phosphine oxide (L) forms the complexes LMnL,]X, and [MnL,Cl,] (X = In both complexes the ligand co-ordinates via the oxygen atom. The comparison with HMPA and Ph,PO complexes is made and the importance of steric factors on stoicheiometry d e m ~ n s t r a t e d . ~ ~ The complexes [Mn(L,)(O,PH,),] (L, = o-phen or bipy) have been reported97 and phenylphosphonic acid forms complexes with Mn" in which ligand-bridging gives rise to cross-linked polymers of stoicheiometry MnL 86

87

88

89 90 91

92 93 94

95

96

''

K. N. Kovalenko, D. V. Kazachenko, V. P. Kurbatov, and L. G. Kovaleva, Russ. J. Inorg. Chem., 1971, 16, 1303. E. L. Simmons and W. W. Wendlandt, J . Inorg. Nuclear Chem., 1971, 33, 3956. G. Peyronel, G. C. Pellacani, A. Pignedoli, and G. Benetti, Inorg. Chim. Acta, 1971, 5, 263. G. V. Tsintsadze, Russ. J . Inorg. Chem., 1971, 16, 614. C . V. Berney and j. M. Weber, Inorg. Chim. Acta. 1971, 5, 375. A. H. M. Flew and W. L. Groenveld, Rec. Trav. chrrn., 1972,91, 317. M. W. G.De Bolster. I. F. Kostram, and W. L. Groenveld, J. Inorg. Nuclear Chem., 1972,34, 575. G Ciani, M. Manassero and M. Sansoni, J . I m r ~Nuclear Chem., 1972, 34, 1760 D. Budd, R. Churchman, D. G. Holah, A. N. Hughes, and B. C Hui, Carmd. J. Chern., 1972, SO, 1008. M . W. G . De Bolster and W. L. Groeneveld, Rec. Trav. chim..1972. 91, 171. M. W. G . De Bolster and W. L. Groeneveld, Rec. Truv. chim.,1971,90, 1153. J . Sala-Pala, R. Kergoat. and J. E. Guerchais Compt. rend., 1972, 274, c', 595.

192


and MnL(H,O). Both compounds are high spin.98 MnCl, reacts with ammonium, potassium, and sodium pyrophosphates at 25 "C to give both normal and mixed salts. The new compounds Mn(NH,),HP20,,H,0 and MnK2P20,,3 H 2 0 have been isolated.99 The MnS0,-MgS0,-H,O and MnSO,-(NH,),SO,-H,O systems have both been studied.'" S-Donor ligands. Mn(S,CNEt), has been prepared in an alcoholic medium; X-ray powder photography shows the compound to be isostructural with the nickel analogue, i.e. planar, and magnetic susceptibility and e x . measurements show it to have a spin quartet ground state."' The dithiocacodyl complexes M(S,AsMe,), (M = Mn, Co, and Ni) have been isolated. The manganese complex is octahedral and the Mn-S bonds appear to be more ionic in character than the corresponding Ni and Co species."* Mixed donor Iigands. The acetylhydrazine complex [ Mn(acetylhydrazine),] C1, has been isolated. 1.r. measurements indicate chelation of the metal atom cia the oxygen atom and the primary amino-group.lo3 N-Hydroxyurea (NH,CO.NHOH) complexes of Mn" have been reported.lo4 The Mn" complex of the potentially quinquedentate Schiff-base ligand (12) derived from two molecules of pyridine-2-carboxaldehyde and one molecule of 1,1,l-tris(aminoethy1)ethanehas been isolated by means of a template

(12)

reaction.'05 The complexes [MnL] have been isolated, where L is a dibasic terdentate Schiff base formed from a 5-substituted salicylaldehyde and either a 5-substituted-0-hydroxyaniline or anthralinic acid. Some of the complexes are isolated as hemihydrates, others as mixed hydrate-ethanolates. Magnetic measurements have been interpreted in favour of either dinuclear or polynuclear structures.' O6 N-Hydroxyethylnaphthalideneimineforms an octahedral Mn" complex of the type (13). This is unique in that the ligand is bidentate in the corresponding Co", Ni", and Cu" complexes, the hydroxy-group not being co-ordinated.l o ' The reaction of [Mn(salpn)H,O] and [Mn(salpn)] (salpn = NN'-disalicylaldehyde-propane- 1,3-diamine) with oxygen has been studied under various 98

99

loo

lo'

lo2

lo3 lo4 lo' lo' lo'

W. C. Ginonneau, P. L. Chapman, A. G . Menke, a n d F. Walmsley, J . Inorg. Nuclear Chern., 1971, 33. 301 1 . M . V. Goloshchapov and B. V . Martynenko. Russ. J . Itiorg. Chmn.. 1971. 16. 1020. V. S. Kublanovskii, V. N. Belinskii, a n d D. P. Zosimovich, Russ. J . Inorg. Chem., 1971, 16, 1598; B. I. Zhelnin and G . I. Gorshtein. ibid, p. 1668.

S. Lahiry and V. K. Anand, Chem. Comm., 1971, 1 1 11. A. T. Casey, D. J. Mackey, a n d R. L. Martin, Austral. J . Chem., 1971, 24. 1587. Y. Y. Kharitonov and R. I . Machkhovshvili. Russ. J . Inorg. Chem.. 1971, 16, 1438: ibid.,p. 492. R. Berger and H . P. Fritz, Z . h'oturforsch, 1972, 27b. 608. S. 0. Wandiga, J. E. Sarneski, a n d F. L. Urbach, Inorg. Chem., 1972, 11, 1349. K. D. Butler, K. S. Murray, a n d B. 0. West, Austral. J . Chem., 1971, 24, 2249. R. K. Mehta and V . G . Singhi. Z . Naturforsch., 1972. 27b, 304.


193

conditions. The results are summarized in Scheme 1. All the products are believed to be polymeric."' [Mn(salpn)H,O] [Mn(salpn)O,(H,O)]

+ [Mn(salpn)O($,H,)]

o,-py [Mn(salpn)O(py)]

1

dry in vacuum

[Mn(salpn)O]

Scheme 1

The potentially terdentate ligand, thiodiethanol, forms the high-spin complex MnCl,,L, which is believed to be five-co-ordinate.' O9 Ethylenedithiodiacetic acid and diethylenetrithioacetic acid form 1: 1 complexes with Mn",' whereas ethylenetetrathiotetra-acetic acid forms both 1i 1 and 1:2 com(L) plexes. a-N-Methyl-S-methyl-~-~-(2-pyridyl)-methylenedithiocarbazate behaves as a neutral terdentate ligand forming the complexes MnLX, (X = C1 or NCS), which are probably polymeric."'

'

Oxides and Sulphides. The influence of annealing temperature and quenching in air on the structural and magnetic properties of the solid solution, (CuFe,,(MnFe,O,),., has been studied. Annealing at 1300 "C 04)o.2(Cu,,5Fe,, 0J0, gives rise to the formation of y-Fe,O,, whereas slow cooling to low temperatures produces a-Fe,O,.' ' The structure of Helvite, hln,(BeSiO,),S, has been reported. The tetrahedral manganese(I1)ions are bonded to one sulphur and three oxygen atoms.' l 4 M,Mn,S, (M = Rb or Cs) have been prepared by reactions in the molten state under nitrogen. An X-ray study on the caesium compound showed the manganese and caesium atoms to be arranged in layers separated by layers of sulphur atoms."5

lo'

'I

*I ' I 3

0

J. D. Miller and F. D. Oliver. J . /nor'F. Nuchar Chem.. 1972, 34, 1873. B. Sen and D. A. Johnsoii. J . hor'q. i~iircleorC'kem.. 1971, 34. 609. J. Podlaha and J. Podlahova. Inorg. Chim. Actu. 1971. 5, 413, 420. P. Petras and J. Podlaha, Inorg. Chiin. Acta, 1972. 6,253. M . Akbar-Ali, S. E. Livingstone. and D. J . Phillips. h r g . Ckini. Acta, 1972, 6, 1 1. M. A. Zinovik, A. A Shchepetkin, and G. I. Chutarcv. Russ. J. Inorg. Chem., 1971, 16, 1433. W. M. Holloway, T. J. Giordano, and D. R. Peacnr, Acto Cry.~t..1972, B28, 114. W. Bronger ant! P. Kiltcher, 2 ,4not.g. Clicm.. 1972. 390. 1 .

194


Manganese(Ir1).--Halides. The crystal structure of [Cr(NH,),][MnF,] has been reported and a dynamic Jahn-Teller effect observed for the MnF:- ion.", The electronic spectrum of K,MnF, has been examined in detail.'17 The structure of K,MnF,,H,O does not involve co-ordination of the water molecule to manganese and consists of manganese atoms linked by trans-bridging fluoride ions giving rise to endless kinked chains containing distorted octahedral co-ordination.' ' * In an attempt to prepare K,MnF,,H,O, Edwards isolated a small yield of K,Mn(SO,)F, when high concentrations of manganese(II1) were employed. The crystal structure of this compound showed the Mn"' atoms to be linked through trans-bridging fluoride ions and bridging sulphate groups giving an endless chain structure with distorted octahedral co-ordination. However. the distortion is of the opposite type to that usually found in octahedra.' ") When KMnO, is mixed with MnC1,,4H20 in conc. HC1 followed by the is formed. addition of [Co(en),]Cl, at - 10 "C, [Co(en),][MnCl,],H,O Spectroscopic and magnetic properties (perf= 4.94 BM at 293 K) have been reported.' 2o Polarized crystal spectra of MnC1:- have been reported. The results indicate C,L7symmetry for (bipH,)[MnCl,] (bipH, = bipyridinium ion) and C,c symmetry when Mn"' is doped into (Et,N),InC1,.121 Cyano-compounds. The reaction of KMnO, and KCN in aqueous solution was originally reported to yield red K,Mn(CN), and later, brown K,Mn,(CN),,4KOH. This reaction has been re-investigated and the red compound found to be K,Mn(CN),. The second product is not as formulated above and may be K,[Mn(CN),H,O],KCN, although this is far from certain.'22 An i.r. and e.s.r. study of the products of -{-irradiation of [Mn(CN),N0I3in alkali-metal halide lattices has been reported. 1.r. evidence was obtained for both [Mn(CN),NO]"- ( n = 2 or 4): however, e.s.r. data confirmed only [Mn(CN),NO]".' 2 3 M O calculations have been reported for fMn(CN),NO]"- (n = 2 or 3) and Fe(CN),N02- and it was four?Gthat the square of the NO stretching frequency correlates with the electron occupancy of the antibonding 2 p orbital on the NO ligand. However, the authors take the reasonable view that the nature of the whole complex must be considered in interpretation of trends between related species.' Cornplexes.Thesolid-state photolysis ofM [ Mn(malonate),(H,O),], 2H,O( M = NH,. Na,or Kj has been investigated. Deaquation to M[Mn(malonate),] is observed, followed by dissociation of the deaquated species to M(malonate), '

ih

'I' I R

I I9

'" '*I

"' lZ3

12'

K . Wieghardt a n d J . Weiss. -4c!ci Cr\.\i . 1972. 828. 529. G. C. Allen, G. A. M. El-Sharka\%y.and K . D. Warren. h o r g . Chem., 1971, 10, 2538. A . J . Edwards, J . Chem. SOC.(.4). 1971. 2653. A. J . Edwards. J . Clirni. Suc. ( A ) . 1971. 3074. W . Lewson. C. A. McAuliffe. and S. Ci. Slurra)-, Inorp. ~vruclpnrChrrn i e t r e r s , 1972. 8, 97. C. Bellito, A. A . G. Tomlinfon. and C Furlani, J . i - h e i l i . S o r . ( A ) . !Y71, 3267. R . A. Bailey and E. N. BaIko. J . 1nor.g A'uclear Clrenr., 1972, -34. 3668. M . B. D. Broom, J. B. Raynor, K . D J . Rnot. and M. C. R. Syrnom, J . Chem. Soc. ( A ) , 1971. 3212. R. F. Fenske and R . L. DeKock. InorK. Ciwm.. 19'72, 11. a?:.


195

Mn(malonate),CO, and water. Mn(ma1onate) further dissociates to Mn(CO,), acetic acid, and C02.125The new complexes [MnL,](ClO,), [L = pyridine N-oxide or antipyrine( 14)] have been isolated. Evidence has been obtained for a tetragonal distortion in both cations.'26 The complexes MnL3C1, (L = pyNO, Ph,PO, or Ph,AsO) have been prepared.127 Me

Me

'h I

I

Ph

The structure of di-p-oxo-tetrakis(bipyridyl)dimanganese(~~~,~v)perchlorate monohydrate has been determined. The cation contains Mn"' and MnIV bridged by two oxygen atoms. The two manganese atoms are unmistakeably different, smaller bond lengths being observed around the Mn" ion.' 2 8 Higher Oxidation States of Manganese.-When XeF, is heated with MnF, at 120 "C for 60 h, wine-red XeMnFSor6is formed. Magnetic data suggest that this is a complex of The electronic spectrum of Cs,MnF, has been studied and the values, Dq = 2180 cm-', B = 650 cm-', C = 3972 cm-' were obtained.13' MnS,, free of monosulphide, can be prepared from MnSO, and alkaline polysulphide solution.' Mn,As is isolated from the reaction of manganese and arsenic under high pressure. It has a structure analogous to Fe,P.13, The solid-state reaction of TeO, and MnO under nitrogen gives rise to the tellurites, MnTe,O,,, MnTe205, MnTe,O,, MnTeO,, Mn,Te,O,,, and Mn,Te, 0,. 1 3 3 The vibrational spectra of M,(MnO,), (M = Ba or Sr) have been examined.' 34 In molten NaNO,, permanganate decomposes via green MnO: and blue Mn0:- to MnO,; peff for the blue Mn0:- is 2.4 BM.135 When manganese is dissolved in molten NaOH at 400 "C in the presence of oxygen and water, only MnV is formed; however, in a KOH melt, both MnV and 39 mole % of MnV'are observed. In molten KNO, 96 mole % of MnV'is formed. G. D'Ascenzo and W. W. Wendlandt, Gazzetta, 1972, 102, 134. C. C. Prabhackaran and C. C. Patel, J . Znorg. Nuclear Chem., 1972,34, 2371. 12' E. Contreras, V. Riera, and R. Uson, Znorg. Nuclear Chem. Letters, 1972, 8, 287. 12' P. M. Plaskin, R. C. Stoufer, M. Mathew, and G. J. Palenik, J . Amer. Chem. SOC.., 1972, 94, 2121. lZ9 B. Zemva, J. Zupan, and J . Slivnik, J . Znorg. Nuclear Chem., 1971, 33, 3953. 130 M. J. Reisfeld, N. A. Matwiyoff, and L. B. Asprey, J. Mol. Spectroscopy, 1971, 39, 8. A. Auroux, B. Bonnetot, and J. Bousquet, Bull. SOC.chim. Fraricc. 1971. 3904 '32 W. Jeitschko and V. Johnson, Acta Cryst., 1972, B28, 1971. 1 3 3 M. Tromel and D. Schmid, Z . anorg. Chem., 1972,387,230. 1 3 4 P. Tarte and J. Thelen, Spectrochim. Acta, 1972, 28A, 5 . 1 3 5 R. B. Temple and G. W. Thickett, Austral. J . Chem., 1972, 25, 655. 125

126

I96


Between 130 and 200°C reversible disproportionation of MnV is observed in both NaOH and KOH.'36Transition-metal manganates of the spinel structure are prepared by the reaction of MnSO, and MSO, ( M = Co, Cu. Zn, or Ni) in a Na,SO,-K,SO, eutectic at 1000-C. The series M x M n 3 - x 0 4 + ywas observed within the limits: Co, 0 < x < 3; Zn, 0 < x < 1.5; Cu, 0 < x < 1; Ni, 0 < .y < 1: the compounds Co,~,Mn,~,O,, Co,~,Mn,,,O,, ZnMn,O,, and Zn,,,, Mn,,,,O, were prepared in high yield: the oxygen-deficient manganates have the limits, 0.02 < y < -0.08.137 The effect of dissolved potassium periodate, bromide. chlorate, perchlorate, or iodate on the decomposition of KMnO, in a Li-KNO, melt has been studied. The first three solutes were found to stabilize permanganate for extended periods, allowing spectroscopic measurements to be made.' 3 8

3 Iron Carbonyl Compounds. -The i.r. spectrum of crystalline Fe(CO), has been recorded at liquid nitrogen temperature and a new assignment of the spectrum is ~ u g g e s t e d . ' ~Irradiation ~" of Fe,(CO), with U.V.light at 20 K gives rise to new bands in the i.r. spectrum which have been assigned to the presence of both the bridged and non-bridged forms of Fe,(CO),.'39 An i.r. and variabletemperature 'H n.m.r. study on [(n-Cp)Fe(CO),], indicates the presence of both cis- and trans-bridged and non-bridged isomers in solution,'40 and However, temperature-dependent 3C n.m.r. spectra support this i~omerism.'~' a 13C n.m.r. study of Fe3(C0),2 showed only one line in the spectrum, indicating either a structure in solution containing only terminal carbonyl groups or rapid terminal-bridged interconversion.' The structure of [Fe,(CO),(n-Cp),] has been determined and consists of a tetrahedral array of metal atoms (Fe-Fe = 2.52 A), each bonded to a x-Cp ligand: the carbonyl groups are triply bridging a b m e each tetrahedral face.142 The electrochemical studies on [Fe4(C0),(~-Cp),] reported last year have been 1 +, 0, 1 -, the cluster published in detail. It exists in the oxidation states 2 remaining intact throughout. The 2 + cation could not be isolated, but the 1 + cation was precipitated as its PF, salt. The 1 - anion was characterized in solution.' 43 The salt [Fe4(C0),(~-Cp),]PF6 can also be obtained by treating the netural compound with AgPF, in dichloromethane. The structure of this salt has been determined and the cation is found to have the same framework as the neutral compound with slight tetragonal distortion. The Fe-Fe distances are decreased slightly to 2.48 8, and these results are interpreted in

+,

136 13' 13'

"'31 139

14' 14'

H. Lux. E. Renauer. and W . Findleiss. 2. anorg. Chem.. 1972. 390, 303. D. R. Petzold. D. Schultze, a n d K . T. Wilke. Z. anorg. Chern., 1971, 386, 288. B. J. Brough. D. A . Habboush. and L) H. ticrr-idg

,

,

,

,

'" G. M . Bancroft and K. D. Butler. J.C.S. Dalton, 1972. 1209. '" j. F. Helling. S. L. Rice. D . M. Braitsch, a n d T. Mayer. Chem. Comm., 1971. 930. 275

A. J . Edwards. J . C . S . Dalton. 1972. 816. W. Massa and W. Riindorff, 2. Naturforsch.. 1971. 26b, 1216. R. Von der Miihll, S. Andersson, and j, Galy. Acra Cryst.. 1971, B27, 2345.

27h

E. N . Deichman. I. V . Tananaev. a n d A. A. Shakhnazaryan, Russ. J. Inorg. Chem., 1971, 16,

213 274

1748; 1754. 277

278 279

E. Frank a n d D . St. P. Bunbury, J . Inorg. Nuclear Chem.. 1972. 34, 535. D. M. Adams a n d D . C . Newton, J.C.S. Dalton. 1972.681. A. E. Klygin, V. A. Glebov, V. A. Lekae, N. S. Kolyada, I . D. Smirnova, N . A. Nikol'skaya, a n d D. M. Zavrazhnova. Russ. J . Iiiorg. Chem.. 1971. 16, 840.


223

FeC1,,0.3H20 > FeCl, > FeOC1.280 The reaction of BBr, with anhydrous FeC1, or anhydrous oxides of Fe"' gives anhydrous FeBr,.," The structure of (4-EtpyH)[FeBr4] has been reported, the anion being tetrahedral.282 The structural determination on [Co(en),][Fe(CN),],2H20 shows the anion to be octahedral, and the series of compounds, [M'(en),][M2(CN),],2 H 2 0 (M' = Co or Cr; M2 = Cr, Mn, Fe, or Co) are all i s o m o r p h ~ u s . ~ ~ ~ The high-energy lattice modes in the Raman spectrum of K,[Fe(CN),] are considered to indicate a higher degree of covalency between the cations and anions than in the corresponding halides.284 The reaction of ferricyanide ions and SO:- has been shown to proceed via [Fe(CN),(CNSO,)]'- and [Fe(CN),(CNSO,)l4-, followed by hydrolysis of the latter to ferrocyanide and sulphate. Appreciable quantities of S,Oi- are also formed.285 Complexes. N-Donor ligands. A full account has appeared286of the preparation and properties of the three-co-ordinate complex Fe[N(SiMe,j,], (see Vol. 1. p. 138). The complex is prepared by the action of Li[N(SiMe,),] on FeC1, in THF. The photoreduction of [Fe(phen),I3' has been studied and it has been demonstrated that water is an electron donor in the photo-reaction. Secondary thermal reactions of [Fe(phen),I3 and O H - also take place.287 Photoreduction of [Fe2(phen),0X2Y2] (X or Y = C1, Br, NCS, or CIO,) in aqueous or acetonitrile solutions yields [Fe(phen),I2' and Fe3+. It has been concluded that the primary photochemical process is homolytic cleavage of the Fe"'-O bridging bond.288The imide complex [FeL3] (L = ben~ofur2-yl-carboximide-N-toluene-p-sulphonylj is prepared by refluxing the ligand and ferric salts in 70% MeOH at pH 8.5.289 The Fe"' complex of (46; R = H), [(MeCN),FeL](BF,), has been r e p ~ r t e d46. ~ Reduction of p-0x0-bis[tetraphenylporphiniron(rrrj] with sodium amalgam gives several products sequentially. The first reduction product is the radicalanion [(tpp)Fe']-, which has a spin state of $ at 77 K and $ at 300 K. This is the first reported study of an Fe'--p~rphyrin.~~' Mossbauer data on a range of tetra-aryl-substituted iron-porphines and their p-0x0-bridged derivatives have been r e p ~ r t e d . *~ 'A crystallographic study on bis(imidazo1e) @yGtetraphenylporphinatoiron(n1) chloride-methanol solvate shows the [FeN,] core to be q ~ a s i t e t r a g o n a l . ,An ~ ~ n.m.r. study has been made of the related +

282 283 284

285

286 287

288

290 2y1

2y2

K. A. Plotnikov. A. A. Krasil'nikova, N. M. El'khones, and A. I. Stepanov, Russ.J. Inorg. Chem., 1971, 16, 788. P. M. Druce and M. F. Lappert, J . Chem. SOC.( A ) , 1971, 3595. M. L. Hacker and R. A. Jacobson, Acta Cryst., 1971, B27, 1658. L. D. C. Bok, J. G . Leipoldt, and S. S . Basson, Z . anorg. Chem., 1972, 389, 307. D. M. Adams and M. H. Hooper, J.C.S. Dalton, 1972, 160. J. M. Lancaster and R. S. Murray, J . Chem. Soc. ( A ) , 1971,2755. E. C. Alyea, D. C. Bradley, and R. G . Copperthwaite, J . C . S . Dalton, 1972, 1580. E. L. Wehryand R . A. Ward, Inorg. Chem., 1971, 10, 2660. P. G. David and J . G. Richardson, J. Inorg. Nuclear Chem.. 1972, 34, 1333. W. U. Malik, C. L. Sharrna, M. C. Jain, and Y. Ashraf, J . Znorg. Nuclear Chem., 1971,33,4333. I. A. Cohen, D. Ostfeld, and B. Lichtenstein, J . Amer. Chem. Soc., 1972. 94, 4522. C. Maricondi, D. K. Straub, and L. M. Epstein, J . Amer. Chem. SOC.,1972, 94, 4157; M . A. Torrens, D. K. Straub, and L. M. Epstein, ibid., 1972, 94,4160, 4162. D. M. Collins, R. Countryman and J . L. Hoard, J . Amer. Chem Soc., 1972, 94, 2066.

224


bispyridineiron(II1)protoporphyrin IX complexes.293The crystal structure of ~-oxo-bis-[~~yG-tetraphenylporphinatoiron(~i~)] shows the iron atoms to have square-pyramidal c o - ~ r d i n a t i o nand . ~ ~ n.m.r. ~ studies have been made of this complex and the corresponding protoporphyrin-IX-dimethyl ester and deuterioporphyrin-IX-dimethylester compounds.295 0-Donor ligands. The nitrilotriacetate chelates of Fe"', FeLn (n = 1, 2, or 3), have been synthesized: all are polymeric.296The complexes (54) of z-hydroxybutyrate (R' = R 2 = Me) and atrolacetate (R1 = Ph. R 2 = Me) have been isolated.29' The thermal decomposition of K,Fe(ox), has been

0

and the stoicheiometry of the reaction at 233-262°C is 2K,Fe(C,O,), -, 2C0, + 2Fe(C204)+ 3K,C204. The iron(ii1) chelate. FeL,, of hydroxymethylenenorcamphor (55) has been isolated.299

The preparations and structures of Ag[Fe(SO,),] and Ag,[Fe(SO,),] have been r e p ~ r t e d , ~as " has the thermal decomposition of Fe2(S04),.30 Equilibration of an aqueous Fe,(S04), solution with a benzene solution of long-chain primary or secondary amines gives rise to polymeric compounds. Mossbauer data are consistent with a structure having a triangular Fe, system with hydr~xy-bridges.~'~ Electronic spectral measurements on (RSO,),Fe (R = Me, Ph. or p-MeC,H,) show a lizand field strength 5imilar to DMS0.303and the 293 294

295

296 297

''' 299 300

301 '02

303

H. A. 0. Hill and K. G . Morallee. J . Amer. Chem SOC.,1972, 94, 731. A. B. Hoffman, D. M. Collins, V. M . Day. E. B. Fleischer, T. S . Srivastava, and J. L. Hoard, J . Amer. Chem. SOC..1972. 94, 3620. M . Wicholas. R. Mustacichand D. Jayne, J . Amer. Chem. SOC..1972. 94,4518. M. Krishnamurthy and K. B. Morris, J . Inorg. .\uclear Chern., 1972, 34, 719. K. K. S. Gupta and A. K. Chatterjee, 2. anory. Chrm., 1971.384,280. J. D. Danforth and J . Dix, hiory. C h t n . . 1971. 10. 1613. L. L. Borer and R. L. Lindtvedt, Inorg. Chem.. 1971, 10, 2113. R. Perret and P. Couchot, Compt. retid.. 1972. 274, C , 1735. T. P. Prasad, J . Inorg. Nuclear Chem., 1972,34. 1094. R. Prados and M. L. Good, J . Inorg. Nuclear Chem.. 1971, 33, 3733. E. Konig, E. Lindner, I . P. Lorenz, G. Ritter, and H. Gaussmann, J . Inorg. Nuclear Chem., 1971, 33. 3305.


225

i.r. spectrum of [Fe(TMS0),]3' is very similar to that of the DMSO anal o g e.~ O FeCl, reacts with Na,HPO, to give FeP0,,2.5H20; with excess Na,HPO,, FePO,,xH3P0,,2.5H,O is formed. Both compounds give crystalline FePO,,2H,O when kept in an acid medium for 2 to 3 days at 80-90°C.304 Mossbauer and Raman data for Fe(O,PF,), and Fe(O,PCl,), have been presented.305 The complexes of nonamethylimidodiphosphoramide (NIPA), [Fe(NIPA),(NCS),]NCS, [Fe(NIPA),Cl,][FeCl,], and [Fe(NIPA),](NO,), have been prepared.306 The reaction of 2-hydroxy-1,4-naphthaquinonewith FeCl, gives dimerization of the quinone to (56) and formation of a complex with one mole of dimer per Fe"', the other co-ordination sites being occupied by H,O or hydroxide ions.307

The dimeric dialkoxy-bridged compounds [L,FeOR], (L = enolate of acac or dipivaloylmethane; R = Me, Et, or Pr') have been prepared by the oxidation of Fe" compounds in alcoholic solutions containing the free ligand and base or directly from Fe"' compounds. The structure (57) is proposed.308

The spectra of [Fe(edtaH)H,O], [Fe(edta)H,O] -, and [Fe(HO-edta)(H,O),] have been examined in the solid state and in solution. All the complexes are found to be seven-co-ordinate in water, methanol, forrnamide, and glycerol 304

'Os 306

307

308

Q

L. S. Eschenko, L. N. Shchegrov, and V. V. Pechkovskii, Russ.J . Inorg. Chem., 1971, 16, 1609. J. Pebler and K. Dehnicke, Z . Naturjorsch., 1971, 26b, 747. M. W. G. De Bolster and W. L. Groenveld, Rec. Trav. chim., 1972,91, 95. C. G. de Lima and A. DuFresne, Inorg. Nuclear Chem. Letters, 1971, 7,843. C. H. S. Wu, G. R. Rossman, H. B. Gray, G. S. Hammond, and H. I. Schugar, Inorg. Chern., 1972, 11, 990.


226

and six-co-ordinate in D M F and DMSO. The results suggest that in solution the complexes contain quinquedentate edta or hydroxy-edta, the number of co-ordinated solvent molecules being determined by the steric requirements of the solvent molecule.309 Magnetic and spectral properties of (enH,)[(FeHedta),0],6H20, Na4[(FeHedta),0],12H,0, [Fe(Hedta)],H,O and Na[Fe(edta)],3H20 have been reported and the results interpreted in terms of a ligand field model., l o The complexes [FeC13],2L (L = 4-picoline N-oxide, (L = 44-MeOpyNO, 4-ClpyNO. or 4-N02pyNO) and [FeL,](ClO,), picoline N-oxide. 4-MeOpyNO, 4-ClpyNO, 4 - N 0 2 p y N 0 , 4-CNpyNO, or 3-CNpyNO) have been prepared, and have been characterized by magnetic 31 measurements and i.r. and electronic FeCI,. when treated with THF. followed by evaporation. freeze drying of a benzene solution, and sublimation, gives golden crystals (73 % yield) of FeCl,,THF. This four-co-ordinate high-spin complex is monomeric in benzene at low concentration and the THF is co-ordinated without ring cleavage., l 2 S-Dortor ligands. The structure of tris-(t-butyl-thioxanthato)iron(IrI) has been determined. The three chelating ligands give distorted octahedral geometry at the iron atom.313Iron(m) complexes of 1,5-bis-(2-mercaptoethylthio)pentane with a meta1:ligand ratio of 1:l are all hydrated and polymeric. Thermal decomposition in air and nitrogen gives dehydration followed by decomposition to the metal ~ u l p h i d el .4~ The structures of high-spin [Fe{ S,CN(CH,),),] and predominately lowspin [Fe(S,CNMePh},] have been determined. Both molecules consist of three substantially planar chelate ligands surrounding the central iron atom in an approximately D, configuration. The angular [FeS,] core geometries are closely comparable but there is a large contraction in the Fe-S bond length on passing from high-spin to low-spin configuration [Fe-S (high-spin) = 2.38(low-spin) = 2.28-2.33 A].315 A study of the relationship 2.44 A. Fe-S between peffand pKa of the parent secondary amine indicates that the primary function of R in the complexes [Fe(S,CNR,),] is as an electron-releasing group rather than a steric-effecting group, except when R has a secondary carbon s u b ~ t i t u e n tl 6. ~A Mossbauer study of [Fe(S,CNR,)3] (R = cyclohexyl, Ru'. Pr'. Me. PhCH,. o r piperidyl) in the range 100-300 K shows a temperature-dependent isomer shift that is nearly identical in all complexes, and a temperature dependence of the quadrupole splitting that falls short of that expected for the T,,-6A ,g equilibrium that is invoked to explain the magnetic

'

309 310

K. Garbett, G . Lang, and R. J.P. Williams, J . Chem. SOC.( A ) , 1971, 3433. H. J. Schugar, G. R. Rossman, C . G. Barraclough, and H. B. Gray, J . Amer. Chem. SOC.,1972, 94. 2683.

3'1

3'2 313 314 315

316

N. M . Karayannis, J. T. Cronin, C. M. Mikulski, L. L. Pytlewski, and M. M. Labes, J . Znorg. h'uclear Chem.. 197 1,33.4344. L . S. Benner and C . A. Root, Inorg. Chem.. 1971. 11. 6 5 2 . D. F. Lewis, S. J. Lippard, and J . A. Zubieta, Znorg. Chem.. 1972, 11, 823. H. F. Steger, J . Znorg. Nuclear Chem., 1971, 33, 3399; 1972, 34, 175. P. C. Healy and A. H. White, Chem. Comm., 1971, 1446;J.C.S. Dalton, 1972, 1163. R. R. Eley. R. R. Myers, and N. V . Duffy, Znorg. Chern.. 1972, 11, 1128.


227

behaviour of these corn pound^.^^' The structure of the square-pyramidal complex [FeI(S,CNEt,),] has been reported.318 The dithiolen complexes, [FeL(S-S)]- [S-S = S,C,(CN),, S,C,(CF,),, or S,C,CI,; L = o-C,H4(AsMe,),,Ph,As(CH2),AsMe2, cis-Ph,PCH=CHPPh,, Me,PhP, or Me,PhAs], [FeL(S-S),] [S-S = S,C2Ph2, L = Ph,As(CH,),AsPh, or Me,PhAs], [Fe{ Ph,As(CH,),AsPh,) (S,C,(p-MeC,H,),),], and [F~(O-C,H,(A~M~,),),(S,C,(CN)~~] have been prepared. The anions are six-co-ordinate when L = o-C,H,(AsMe,),, Ph,PCH=CHPPh,, or Ph,As(CH,),ASP~,.~'' The reaction of [Fe(S,CNR'R'),] with Na,(mnt), followed by oxidation of the resulting anions with air and Cu" in acetonitrile, gives [Fe(S,CNR'R'),(mnt)] (R1,R2 = Et, Et or Et, Ph; mnt = maleonitriledithiolate). Both compounds show singlet + triplet spin equilibrium and both are stereochemically non-rigid, displaying two distinct kinetic processes when examined by variable-temperature n.m.r. At lower temperatures there is an inversion process, the most likely mechanism for which is a twisting about the pseudo-threefold axis and at higher temperatures the process of rotation about the C-N bond can be ~bserved.,~' The reaction of triphenylphosphole, its oxide, sulphide, and selenide with Fe"' has been studied. The phosphole reduces Mixed donor ligands. Tris(acetylhydrazine)iron(m) trichloride has been prepared.'', The effect of pressure on ferric hydroxamates is to cause reduction to iron(rr), the amount of reduction being correlated with the position of the metal + ligand charge-transfer band.321 Fe3+ complexes of N-hydroxyurea (58) forms the have been isolated.' O4 8-Amino-7-hydroxy-4-methylcoumarin complex [Fe,L,Cl,], in which the Fe"' ions are in octahedral environment^.^,, A magnetic and Mossbauer study of [FeX(ox),] and [FeX,(ox)] (X = C1 or

Me

Br ; oxH = quinolin-8-01) suggests that both complexes exist as magnetically isolated dimers in the solid state.,,, The complexes [Fe(met)(OH)X],2MeOH (X = C1 or NO, met = DL-methionineY have been isolated and evidence 317

318 '19

320 321

322

323

P. B. Merrithew and P. G. Rasmussen, Znorg. Chem., 1972, 11, 325. P. C. Healy, A. H. White, and B. F. Hoskins, J.C.S. Dalton, 1972, 1369. J. A. McCleverty and D. G . Orchard, J . Chern. SOC.( A ) , 1971, 3784. L. H. Pignolet, R. A. Lewis, and R. H. Holm, Znorg. Chem., 1972, 11, 99. D . C. Grenoble and H. G . Drickamer, Proc. Nat. Acad. Sci. U . S . A . , 1971,68, 549. D. K. Rastogi, A. K. Srivastava, P. C. Jain, and B. R. Agarwall, Znorg. Chim. Acta, 1972,6, 145. D. Cunningham, M. J. Frazer, A. H. Qureshi, F. B. Taylor, and B. W. Dale, J.C.S. Dalton, 1972, 1090.

228


has been presented that indicates that co-ordination does not take place via the thioether group.324 Organometallic derivatives of NW-ethylenebis(salicylidineiminato)iron(m), [RFe(salen)] (R = Ph or PhCH,), have been prepared either by treatment of [Fe"(salen)] with sodium in THF, followed by RCI at -60°C or by treatment of [Fe(salen)I] with the Grignard reagent in THF. Evidence was also presented for [Fe(salen)COMe] but this was not isolated in a pure state. All complexes are high spin and are the first examples of high-spin organometallics of Fe"'. [Fe"(salen)] also reacts with cyclohexylisonitrile. but not with CO.,,' S-Methyl-N-(2-pyridyl)methylenedithiocarbazate(nns) can be prepared by the condensation of S-methyldithiocarbazate and pyridine-2-aldehyde. The low-spin complexes [Fe(nns),]X (X = C10, or FeC1,) have both been isolated.326 2,1,3-Benzothiodiazole. 2,1.3-benzoselenodiazole, and their derivatives (L) form the octahedral complexes FeL,C1,.327 and morpholine-4carbodithioate (mdtc) forms the complex [ F e ( m d t ~ ) , ] . ~ 'Mossbauer ~ and magnetic data for a series of monothio-P-diketonate-iron(II1) complexes have been interpreted in terms of a thermal equilibrium between the sextet and doublet states.329 Iron(Iv).-When [Fe(S2CNR2)Jis treated with BF, and air, [Fe(S2CNR2),]BF, [R = Me. Et, Pr'. cyclohexyl: R 2 = (CH,),] are isolated. Treatment of the diethyldithiocarbamate-iron(rrI) complex with KPF,, air, and 18M-H2S0, yields [Fe(S,CNEt,),]PF,. The magnetic moments of these compounds are in the range 3.2--3.4 BM. As the expected value for octahedral iron(1v) is 3.6 BM, a slight distortion is suggested. 1.r. measurements indicate greater S + Fe rr-bonding than in the Fe"' complexes. and it has been established that the oxidant is air. although the isolation of the pure salts can only be achieved when the counter-ion is present. This paper includes a brief report of the corresponding manganese(iv) and the even more interesting cobalt(rv) complexes [M(S,CNEt2)3]BF,.3 3 0 Other Iron Compounds of Biological Interest.-The valency of iron in a range of ferredoxin extracts has been determined by ESCA.,,l The structure of the Fe--S complex in a bacterial ferredoxin has been determined. The iron and sulphur atoms occupy alternate corners of a cube and four more sulphur atoms project from the iron atoms."' Admission of oxygen to a neutral solution of Fe" and excess penicillamine gives a red bis-complex, which is relatively stable in aqueous solution at room temperature Quantitative 325 "'.

326

327 32*

329

330 33i '32

E .i.Halbert and M . j,Rogerson. Austral. J . Chem.. 1972, 25. 411. C. Floriani and F. Calderazzo. J . Chem. SOC.( A ) , 1971. 3665. M. Akbar-Ah, S. E. Livingstone. a n d D. I. Phillips. Inorg. Chim. Acfa. 1971. 5. 493. R. H . Hanson and C. E. Meloan. Inorg. Nuclear Chem. Letters, 1971, 7,467. G. Aravamudan. D. H. Brown, and D. Vankappayya, J . Chem. SOC.( A ) , 1971,2744. M. Cox. J. J. Darken. B. W. Fitzsimmons, A. W. Smith. L. F. Larkworthy, and K. A. Rodgers, J.C.S. Daliott. 1972. 1192. E . A . Pasek and D. K. Straub, Inorg. Chem.. 1972, 11.259. D. Leibfritz. Angeu. Chcm. internat. Edn., 1972, 11. 232. L . C. Sieker. E . Adman. a n d L. M . Jensen. Nature. 1971, 235, 40.


229 determinations show that one mole of H,O, is required for each mole of Fe" for maximal development of the red colour in solutions containing three equivalents of penicillamine. This indicates that, for each mole of Fe", one mole of sulphydryl compound also undergoes oxidation and suggests a link between Fe"'-catalysed oxidation of sulphydryl compounds and oxygen.,,, Oxides and Hydroxides. -BaFe,O, undergoes polymorphic transitions between 800 and 1000°C the resulting phases being orthorhombic y-BaFe,O, (stable up to 800 "C), orthorhombic-pseudohexagonal P-BaFe,O, (stable up to 1000"C), and hexagonal a-BaFe,O, (stable above 1000"C).334The structure of Brownmillerite, Ca,FeAlO,, has sheets of corner-sharing [Fe, All-0 octahedra connected to single chains of [Al, Fe]-0 tetrahedra.335 Mossbauer studies have been made on rapidly quenched samples of Fe,-,O (0.053 < x < 0.109) and interpreted in terms of possible defect structures. A t greater than 500°C the results can be interpreted in terms of (1 - 4z)Fe, -,O -+ (1 - 4x)Fe,-,O + (x - z)Fe,O, and at greater than 570"C, in terms of 4Fe, -zO + (1 - 4z)Fe + Fe,O,. The activation energies have been calculated for the jump processes at 1074 and 1173 K.336Only iron oxide forms a ternary oxide with liquid Na, oxides of Co, Ni, and Cu being reduced to the metal and Na,O. The stoicheiometries and rates of these reactions have been meas~red.~ Magnetic studies on the co-precipitated hydroxides of Cd2+, Fe3+, and [Nil -xFel +J04, showing Ni2+ have been performed, the ferrites Cd,Fe, -, characteristic properties in which the primary ferromagnetism is due to y - ~ e , o , . ,3 8 4 Cobalt

Carbonyl Compounds.-The reaction of Er-Hg( 1%) with Mg[Co(CO),], in T H F at room temperature gives the dark-red air-sensitive solid. Er[Co(CO),],,4THF.,,' Na[Co(CO),] reacts with [(n-Cp)NiLX] under similar conditions to yield [(K-C~)N~CO(CO),L] (L = tertiary phosphine or arsine); i.r. evidence containing a metal-metal suggests the structure (K-C~)N~(~-CO),CO(CO),L, bond, migration of L to the cobalt atom having taken place. The existence of both bridged and non-bridged forms in solution is also suggested.340 trans[ML,Cl,] (M = Pd or Pt ;L = py, 4-Mepy, or 3-Mepy) reacts with [Co(CO),] to yield trans-[ML, { Co(CO),) ,] .3 Na[Co(CO),] and AlCl,, when mixed in benzene at 30'C for three days, gives the deep-red, volatile [AlCo,(CO),] in 25-30 :{ yield. 1.r. evidence 333 334

335 336 337 338 339

340

L. G. Stadtherr and R. B. Martin, Znorg. Chem., 1972, 11, 92. S. Mariani, Acta Cryst., 1972, B28, 1241. A. A. Colville and S . Geller, Acta Cryst., 1971, B27, 2311. N. N. Greenwood and A. T. Howe, J.C.S. Dalton, 1972. 110, 116, 122. C. C. Addison, M. G. Barker, and A. J. Hooper, J . C . S . Dalton, 1972, 1017; C . C. Addison and R. J. Pulham, ibid., p. 1020. W. Wolski, Monatsh., 1972, 103, 775. R. S. Marianelli and M. T. Durney, J . Organometallic Chem., 1971,32, C41. A. R. Manning, J . Organometallic Chem., 1972, 40, C73.


230

,

indicates a structure similar to Co,(CO), with the Co(CO), being replaced by A1 (59). This paper also mentions the preparation of [(7c-Cp),TiCo2(CO),] and [(R-C~),Z~,CO,(CO),] by the same type of reaction: however, no details Al

are given.341The complex [ClIn{Co(CO),),] has been reported.161 Hg[Co(CO),], reacts with PR, in the absence of light to yield Hg[Co(CO),(PR,)], and under more vigorous conditions Hg[Co(CO),(PR,),], is formed [R, = Et,, Bu:, PhMe,, PhPr;, Ph,Me, (NEt,),. Ph,(OMe), Ph(OMe)2. (OMe),, (0Ph)(OCH ,) 2, (0P h ,) or (2-C1C0H 3]. Ph P(CH2 ) PPh (dp) gives [(dp)Co,(CO),Hg] and [{(dp)Co(CO),:,Hg], and the arsine (da) analogues have also been prepared.,",

,,

,

Anionic Conzplexes. [Co(CO),(CN),I2 - reacts with phosphines, PR,, in

aqueous methanol at room temperature to yield [Co(CN),(CO)(PR,),] - (R = Et or Ph) and with liquid PR, or PR, in butanol to give [Co(CN)(CO),(PR,),] ( R = Ph, Et. or cyclohexyl). When the aqueous methanol reaction is performed with P(cyclohexyl),, [Co(CN),(CO),P(cyclohexyl)3] - is isolated, steric factors presumably being important here. All the complexes are oxygen-sensitive, but when an aqueous solution of [Co(CN),(CO)(PEt,),]- is maintained at pH 4,[HCo(CN),(CO)(PEt,),] is formed. The ditertiary phosphine complexes show only weak nucleophilicity towards organic bases, but treatment with alkaline [Fe(CN),I3 - gives carbonate ions and possibly [(CN),Fe-CNCo(CN),(PEt,),(OH,)].- This ready oxidation of co-ordinated CO to C o g is of considerable interest.343 Group ZVA Donor Ligands. The anomalous reactions of Ph,SiCI with metal carbonyl anions are discussed on p. 180. Only in the case of [Co(CO),PPh,]was the normal substitution product obtained.' GeH,Br reacts with Na[Co(CO),] in ether to produce [H,GeCo(CO),]. The trideuterio-compound has also been prepared and spectroscopic properties reported for both comp o u n d ~ . ~The ' ~ preparation and attempted preparation of halogen-bridged Ge-M compounds is referred to on pp. 180 and 200. In the case of cobalt.

321 3J2

343 344

K. E. Schw-arzhaus and H. Steiger, Angew. Chem. Infernat. Edn., 1972, 11. 535. and A. R. Manning. J . C . S . Dalton. 1972, 241. J. Bercaw. G . Guastallo. and J. Halpern, Chem. Comm.. 1971. 1594. R . D. George, K. M . Mackey. a n d S. T. Stobart. J.C.S. Daftnri. 1972. 974. j.Newan


23 1

irradiation of [Me,CIGeCo(CO),]

gave [(M~,C~),CO,(CO),].'~[(K-

U.V.

Cp)Co(CO),] reacts with Me,Sn, by$anoxidative elimination to yield [(Me,Sn),Co(CO)(x-Cp)] which decomposes to the dimer [Me,SnCo(CO)(n-

cp)) 2 .

45

Group V A Donor Ligands. The paramagnetic compounds, [Co(CO)JPR,)I 3 (R, = Bu;, Bu;Ph, or Ph,), have been isolated during stoicheiometric hydroformylation reactions of linear ~ t - o l e f i n uiz s ~ :~ ~

A study of the bridged-non-bridged equilibria of [Co(CO),(MR,)], has been made. When R = Et and M = P only a small amount of the bridged isomer is observed: however, when R = Et and M = As a marked increase is seen in the amount of bridged isomer, the amount of bridged isomer decreasing again for R = Et and M = Sb. The equilibrium also depends on the nature of R.347 The complexes [LCo,(CO),], [LCo,(CO),HC,Ph], [(ffars)Co,(CO),], [MeC *Co,(CO),(ffars)], and [Co,(CO),(ffars),] have been characterized and ligand-bridging structures ascribed on the basis of i.r. data (L and ffars are fluorocarbon-bridged ditertiary phosphines and a r ~ i n e s ) . ~The ~ ' structures of ethylidene heptacarbonyl-p-[ 1,2-bis(dimethylarsino)tetrafluorocycl obuteneltriangulo-tricobalt (60), in which the acetylene moiety is bonded symmetrically above the cobalt triangle, and di-p-[1,2-bis(dimethylarsino)tetrafluorocyclobuteneloctacarbonyl-tetrahedro-tetracobalt,which has a related structure. have been reported.349* 350 C

I\\

(60)

Group VZA Donor Ligands. The structures of [FeCo,(CO),X] (X = S, Se, or Te) and their relation to [Co3(CO),X] are discussed on p. 207. [Co,Fe(CO),S]

has been prepared by a new route starting from [Co,(CO),(SC,X,),] 345

346

341 348

349

350

instead

E. W. Abel and S . Moorhouse, Inorg. Nuclear Chem. Letters, 1971, 7, 905. G. F. Pregaglia, A. Andreetta, G. F. Ferrari, and G. Montrasi, J . Orgartometallic Clienz., 1971, 33, 73. D. J. Thornhill and A. R. Manning, J . Organometallic Chem., 1972, 37, C41. J. P. Crow and W. R. Cullen, Znorg. Chem., 1971, 10, 2165. F. W. B. Einstein and R. D. G. Jones, Inorg. Chem., 1972, 11, 395. F. W. B. Einstein and R. D. G. Jones, J . Chem. Sor. ( A ) , 1971, 3359.


232

of [Fe,(CO),S,] and the differences in reactivity of [Fe,(CO),(SR),] and [Co,(CO),(SR),] have been rationalized in terms of their different electronic

configuration^.^^ The reaction of Co,(CO), and [Me,P(S)], in chloroform or methylene dichloride yields Co,(CO), and the new cluster compounds, [SCo,(CO),(PMe,),] and [S,Co,(CO),PMe,]. Structure (61) has been proposed for the latter. whereas four possible structures were considered for the former, all based on a tetrahedral array of cobalt atoms. In two of the possible structures the Me,P-PMe, molecule remains intact, whereas the other two contain discrete Me,P units.352Co,(CO), reacts with (CF3),S2 under U.V. light to give [Co,(CO),CF] and a trace of [CO,(CO),S],.~~

(61)

Other Complexes. Co,(CO), reacts with Ph,PC-C( CF,) in benzene to yield (62). the structure of which has been determined by X-ray methods.353The

structure of [CCo,(CO),], has been reported and is shown in (63).354

353

G. Natile and G. Bor, J . Orgrr,lo,,lrtclllic, Chem., 1972, 35, 185. G. Natile, S . Pipnataro. G. Tanorta, and G. Bor, J . Organomefallic~Chern., 1972, 40, 215. N . K. Hota. H. A. Patel, A. J. Carty, M . Mathew. :ind G. J. Palenik, J. Organometallic Chem.,

354

M.D. Briceand B. R. Penfold, Inorg. Chem.. 1972. 11, 1381.

351

3s2

1971. 32. C55.


233

Reactions of Co-ordinated CO. Following the reports cited in Volume 1 (p. 168) of silyl-ether type metal carbonyls, a further example has been reported. Thus excess Co,(CO), reacts with R,SiH2 (R = Ph or Et) to give the complex [R,SiCo,(CO),,]. On the basis of i.r. and mass spectral evidence structure (64) is proposed.355Co,(CO), also reacts with C13BNEt3 in a 7:9 mole ratio R

to give the paramagnetic cluster compound [Co3(CO),(COBC12NEt3),1. Structure (65) is proposed on the basis of magnetic and spectral evidence.356 [Co"'(chel)(OH)(H,O)] reacts with CO in the pH range 4-13 to yield [Co"(chel)]. The mechanism suggested is formation of [ C O ' ~ ~ ( C ~ ~ ~ ) ( C O , H ) ( H ~ O ) via nucleophilic attack of OH- on the intermediate [Co"'(chel)(CO)(OH)], the carboxylate decomposing to C 0 2 and [Co'(chel)]-, which in turn, gives [Co"(chel)] by differing reaction pathways depending on the pH of the solution [chel = (66)-(68)]. The same mechanism operates with the complex of 2,3,9,10 - tetramethyl - 1,4,8,11- tetra - azaundeca - 1,3,8,10- tetraen - 11 - 01 - 1 olato anion up to pH 8, whereas in more alkaline solution (pH 13), [Co'(chel)CO] can be isolated. With all the chelates investigated, the reaction appears to be a u t ~ c a t a l y t i c . ~ ~ ~

355

356 357

S. A. Fieldhouse, A. J. Cleland, B. H. Freeland, C . D. M. Mann, and R. J. O'Brien, J . Chem. SOC.( A ) , 1971, 2536. G. Schmid and B. Sutte, J . Organometallic Chem., 1972, 37, 375. G. Costa, G. Mestroni, and G . Tauzher, J.C.S. Dalton, 1972, 450.

234


(68)

Nitrosyl Compounds.-The reaction of [Co(CO),NO] and NO in a sealed tube at 50-60’C and 20 atm for 5-10 days gives [Co(NO),(NO,)], and [CO,(NO),(NO,),(N,O,)], the latter in 2-5 0,; yields. At 60°C, small yields of Co(NO), (see Vol. 1 p. 168) are also formed. The [CO,(NO)~(NO,),(N,O,)] complex (69) is insoluble in organic solvents and is not air-sensitive [v(NO) occurs at 1850 and 1796 cm-l]. The complex contains the hitherto unknown trans-hyponitrite group, and the Co-N-0 bond angles of the four independent nitrosyl groups range from 162 to 167’. The nitrite linkage is also unusual bond in its bond dimensions. [Co(NO),(NO,)], also contains Co-N-0 bond angles has in the pngles of 162 and 163”.358The question of M-N-0 past centred on the differences between 120 and 180” angles; however, there is now mounting evidence for angles of cn. 160” in metal nitrosyls and this is not easily rationalized.

Four distinct species [CoL,(CO)NO] (L = bipy, o-phen, or di-2-pyridyl ketone) have been identified : dianion, radical-anion, neutral complex, and radical-cation., l 4 [Co(CO),(NO)PPh,] has slightly distorted tetrahedral linkage.359 A second group have co-ordination and a linear Co-N-0 reported the structure of this compound and that of [Co(CO)(NO)(PPh,),] and find that both have distorted tetrahedral geometry; however, the CO and NO groups could not be distinguished due to disorder.360 [(n-Cp)Co(CO)PPh,] reacts with NOPF, in methanol-toluene to yield 3s8 35y 360

R. Bau. I . M. Sabherwal. a n d A. B. Burg. J . Amer. Chem. SOC.,1971, 93,4926. D. L. Ward. C . N . Caughan, G. E. Voecks. and P. W. Jennings, Acta Cryst.. 1972, B28, 1949. V. G. Albano, P. L. Bellon, and G. Ciani. J. Orgatlometallic Chem.. 1972, 38, 155.


23 5

[(x-Cp)Co(NO)PPh,]PF,. The corresponding rhodium compound is prepared by an analogous reaction, but the iridium complex yields [(n-Cp)IrH(CO) PPh,]PF,.13 Treatment of [Co(NO)(CO)L,] [L = Ph,P, (PhO),P, or MePh,P; L, = Ph,P(CH,),PPh,] with NOPF, under identical conditions is a convenient route to [Co(NO)L,]+ cations. These cations react with bromide to give [Co(NO),LBr] (L = PPh,) or [Co(NO),L,Br] (L = diphos). It is uncertain whether the latter contains unidentate diphos. or is another example of a complex containing two N O groups, one formally NO', the with BH, yields [Co(NO)other NO-. The reduction of [Co(NO),(PPh,),] (PPh,),] and NH3.,,l The 59C0n.m.r. of [Co(NO),X(PR,)] [R = H, alkyl, 0-alkyl, N(alkyl),, C1, CN, Ph, substituted Ph, or vinyl; X = Cl, Br, or I] has been reported. A relationship has been found between the chemical shift and the bonding parameters of X and OR,.,,, [(n-Cp)Co(NO)], reacts with PhXXPh and Ph,PPPh, to yield [(n-Cp)Co(XPh)(NO)Co(n-Cp)] (X = S or Se) and [(ls-Cp)Co(PPh,)(NO)Co(n-Cp)], respectively.363When Co(OAc),,4H20 is treated with NO at 0°C in methanol and dmgH, is added dropwise, [Co"(dmgH),NO] is formed [v(NO) = 1641 cm-'I. When this complex is treated with water and oxygen, [ColI1(dmgH),N02],H,0 is formed: the intermediate [Co"(dmgH),NO OH,][C0"~(dmgH),N0,],2H,0 has also been isolated from this reaction. It is thought that the latter contains Co" bound to Co"' by an N O bridge.364The reaction of [Co(en),NO]ClO, with dithiocarbamate yields [Co(NO)(S,CNMe,),]. The structure of this compound contains a tetragonal-pyramidally co-ordinated Co atom, the NO group lying at the apex. The NO group is disordered such that the oxygen atom alternately lies above one or other of the sulphur-cobalt bonds in the same dithiocarbamate ligand ( L Co-N-0 = 134.5 and 135.7°).365 Methanol or acetone solutions of [CoL,(NO)] [L, = NN'-ethylene-bis-( 1-acetonylethylideneiminato), NN'-et hylene- bis(benzoylisopropyleneiminato), or NN'-ethylene-bis(salicylideneiminato)] reacts with oxygen at room temperature in the presence of a donor ligand (B) to give [BCoL,(NO,)], the rate of reaction increasing with increasing basicity of B. A similar reaction of [Co(en),NO](ClO,), in acetonitrile gives [Co(en),(MeCN)N0,](C10,),.3 6 6 The structure of [Co(CN),N0I3- has been studied by spectral means.1.r. and electronic spectra indicate it should be reformulated as [(CN),Co(N,O,)Co(CN),I6- : howet er, the appearance of \#(NO)in range 1770-1860 cm- in dilute solution is taken as evidence for a monomer-dimer equilibrium.367 +

361

362 363 364

365 366 367

B. F. G . Johnson, S. Bhaduri, and N. G . Connelly, J . Organometallic Chem., 1972, 40, C36. D. Rehder and J. Schmidt, Z . Naturforsch., 1972, 27b, 625. H. Brunner and S. Lockot, Z . Naturforsch., 1972, 27b, 757. M. Tamaki, I. Masuda, and K. Shinra, Bull. Chem. Soc. Japan, 1972, 45, 171. J. H. Enemarkand R. D. Feltham, J.C.S. Dalton, 1972, 718. S . G. Clarkson and F. Basolo, J . C . S . Chem. Comm., 1972, 670. B. Jezowska-Trzebiatowska, J. Hanuza, 0. Ostern, and J. Ziolkowski, Inorg. Chim. Acta, 1972, 6, 141.


236

Cobalt(r).- Anhydrous CoX,(X --= C1,Br. or I) can be reduced by BH, in the presence of MeC(CH,PPh,), to form [CoXL], which are non-electrolytes and isomorphous with the analogous Cu' complexes. Pseudo-tetrahedral geometry is proposed.368

Cobalt(rI)..-Halides arid Pseuciohalides. An n.m.r. study has been made of cobalt(r1)halides in acetone. acetonitrile, acrylonitrile, and DMSO., 6 9 Fluoride complexes of Co'l have been studied by means of a fluoride-ion selective electrode. and the complex [CoF(aq)]+ was identified.61 The electronic spectrum ~~ of KC OF,^^' and the magnetic properties of BaCoF, and P ~ , C O F ,have been examined. Thermal decomposition of CoF2.4H,0 and CoF2,4NH3 has been investigated,225and a study has been made of the dehydration of CoCl2,6 H 2 0 in the solid state. The reaction CoCl,, nH,O(s)

--$

CoCl,, rnH,O(s)

+ ( n - rn)H,O(v)

( n = 6,4,2, or 1: 171 = 4,2. 1, or 0) has been found to appiy and thermodynamic parameters calculated for the r e a ~ t i o n s . ~ ' [ 3 - (2 - Diethylammoniumethoxy)- 1.2 - benzisothiazole]tetrachlorocobalt ate@) has slightly distorted tetrahedral anions:372however, the distortions are angles varying much larger in [Ihi~tamineH,]~'[COCI,]~-, the Cl-Co-C1 by as much as 9.6.3.373An examination of the electronic and i.r. spectra of CoCl2- and CoCl; together with various counter-ions in organic solvents, shows that a change from R,N+ to R3NH+ gives a change in the spectra attributed to participation of co-ordinated ligands in hydrogen bonding to the R,NH ion, thereby distorting the tetrahedral symmetry.374The i.r. spectrum of CoCIi- has been reported in the region 3000-4000 cm-' and a band at 3400 cm-' has been tentatively assigned to the ,A, -+ ,T2 transition of tetrahedral C O " . ~ The ' ~ Co2+-HCl-H,0 system has been examined over a wide HCl concentration range, and the species CoCI, and H,CoCl, were identified.279The complexes D,CoX, (X = Cl or Br: D + = 2,4-dimethyl-lN-1,5benzodiazepinium cation) have been prepared and the cation is not co~rdinated.~ Anhydrous CoBr, has been prepared by the action of BBr, on the anhydrous chloride.281O n the basis of a detailed i.r. study, it has been suggested that CoBr,,6H,O does not contain the [CO(H,O),]~+ cation but should be formulated as [ C O B ~ , ( H , O ) , ] , ~ H , O . ~ ~ ~ 1.r. studies suggest that the Co(CN):- anion has square-based pyramidal geometry in aqueous solution.37' +

36R

369 3i0

"'

3'2 3 ' 374

375 376

37'

L. Sacconi and S . Midollini. J.C.S. Dalton. 1972. 1213. G. Beech and K. Miller. J . C . S . Dalrori. 1972. 801. J. Ferguson, T. E. Wood, and H. J. Gugpenheim. Austral. J . Chem.. 1972, 25, 453. W.K. Grindstaff and N. Fogel, J.C.S. Dalfon. 1972. 1476. A . C. Bonamartini. M . Nardelli. and C. Palmieri. Acta Crxst.. 1972, B28, 1207. J . J. Bonnet and Y. Jeannin, Acta Cryst.. 1972. B28. 1079. M. G. Kuzina, A. A. Lipovskii. and S. A. Nikitina, Russ. J . h o r g . Chem., 1971, 16, 1313. M. B. Quinn and D. W . Smith, J . Chem. SOC.( A ) , 1971, 2496. D. M . A d a m and P. J. Lock, J . Chem. SOC.( A ) , 1971.2801. W. P. Griffith and J. R. Lane. J.C.S. Da/foti. 1972, 158.


237

Complexes. Arnine complexes. Thermal decomposition of [Co(NH,),](NO,), or [{ CO"'(NH~),)~O](NO~), under vacuum gives the complex [Co(NH,),(NO,),]. This reacts with iodide in organic solvents to give [Co(NH,),I(NO,)] and ultimately [Co(NH,),I,]. The dinitrate is six-co-ordinate containing bidentate nitrato-groups, and the nitrato-group is also bidentate in the iodonitrate.378The heats of formation and thermodynamic functions have been calculated for complexes of CoCl, and aniline and its derivatives in acetone., 7 9 The complexes CoL,X, (L = 0-,rn-, p-toluidene, anisidene, or phenetidene: X = C1, CNS, or $SO,) have been prepared: all are six-co-ordinate with The complex CoS04.2(allylamine) has been isolated.381 bridging X The octahedral complexes [CoL,X,] (L = NN'-dibenzylethylenediamine, X = NCS or NCSe) have been reported382and a study has been made of the oxygen uptake by various Co" complexes of en. The uptake attains a maximum when Co:en = 1 : 3 and, in the isolated products, Co:en ratios vary between 1 : 1.5 and 1:2.75.382"In a study of the nature of the counter-ion on the structure of 1,1,7,7-tetraethyldiethylenetriamineand diethylenetriamine pseudohalide metal complexes, only the five-co-ordinate [Co(Et,dien)(NCX),] (X = S, Se, or 0)complexes could be isolated.383 Three isomers of [Co(dien),]'+ have been separated; namely the s-cis, u-cis, and trans forms; the u-cis and trans forms were resolved uia diastereoisomer formation and the configurations were unequivocally assigned to the geometric isomers from the different racemization behaviour of the u-cis and trans optical isomer^.^ 84 The structure of [Co(trpn)Br]Br,O.SEtOH [trpn = tris-(3-aminopropylamine)] has been reported. The cation has trigonal-bipyramidal co-ordination with the axial Co-N bond longer than the equatorial ones and the very long Co-Br bond [2.658(3) A] is approaching the limit of what could be termed c o - ~ r d i n a t i o n . ~ ~ ~ Pyridine and related ligands. A far-i.r. study of the complexes C0(py)~(N0,), has been reported in order to determine which of the previously reported stoicheiometries exist, and the complexes with x = 3 and 6 were identified.386 The complexes [CoL,(H,O),]X, (L = P-picoline or 3-ethylpyridine; X = Br ' complex [Co(3pyC0,),],4H20, which has or I) have been r e p ~ r t e d . ~The octahedral co-ordination with trans N and four cis H,O molecules [i.e. the non-classical zwitterion (70)] has been used as a model for the structural assignments on other compounds. Thus the corresponding Ni" complex and the Ni" and Co" complexes of pyridine-4-carboxylic acid and -3-sulphonic acid are also formulated with non-classical zwitterionic structures.387The G . L. McPherson, J. A. Wed, and J. K. Kinnaird, Inorg. Chem., 1971, 10, 1574. T. V. Zhurba and V. I. Dulova, Russ. J . Inorg. Chem., 1971, 16, 1168. 3 M 0 S. N. Das, S. N. Moharana, and K. C. Dash, J . Inorg. Nuclear Chem., 1971,33, 3739. 3 8 1 M. S. Barvinok, Y. B. Kalugin, and L. A. Obozova, Russ. J . Inorg. Chem., 1971, 16, 1617. 3 8 2 K. C. Pate1 and D. E. Goldberg, J . Inorg. Nuclear Chem., 1972, 34, 637. 3820 P. Bijl and G. de Vries, J.C.S. Dalton, 1972, 303. 3 8 3 J. L. Burmeister, T. P. O'Sullivan, and K. A. Johnson, Inorg. Chem., 1971, 10, 1803. 384 F. R. Keene and G . H. Searle, Inorg. Chem., 1972, 11, 148. 385 J. L. Schafer and K. N. Raymond, Inorg. Chem., 1971, 10, 1799. 3 8 6 R. H. Nuttall, A. F. Cameron, and D. W. Taylor, J . Chem. SOC. ( A ) , 1971, 3103. 387 A. Anagnostopoulos, R. W. Matthews, and R. Walton, Canad. J . Chem., 1972,50, 1307. 378

379

238


complexes CoX2(2,2'-dtdp) and CoX2(4,4'-dtdp) (X = C1 or Br; dtdp = dithiodipyridine) have only Co-N co-ordination of the organic ligands. The 2.2'-dtdp complexes are four-co-ordinate and the ligand may be bidentate or bridging. and the 4,4'-dtdp complexes are six-co-ordinate polymers with halide study of CoL(PF,), (L = ? - p C H = N R ; R = Me. Et, b r i d ~ e sA. ~'H~ n.m.r ~

Pr', OH, or p-tolyl) shows the presence of both cis- and trans-isomers of L in equilibrium. The CO" complexes are the most suitable for detection of this type of isomerization, although the complexes of Fe", Ni", and Zn" have also been examined. The distribution of isomers depends on the bulkiness of R, the solvent, and the temperature.236 N-(2-Benzothiazole)-2-pyridinaldimine(7 1) forms the octahedral complexes CoL,(C10,),.2H20. CoL,(NO,),,H,O. and CoL,SO,,H,O in which the ligand chelates ciu both nitrogen atoms of the 2-pyridinaldimine'~ystem.~~~ The related ligand (72) reacts with CoCI, in methanol to form (73), reaction with the solvent having taken place during the preparation. Spectroscopic, magnetic, and crystallographic data are presented for (73) and the Co atom is in a tetrahedral e n ~ i r o n m e n t . ~ ~ '

388

389 390

J. R. Ferraro, B. B. Murray, and N. J. Wieckowicz. J . Inorg. Nuclear Chem., 1972, 34,231. A. Montenero and C. Pelizzi, Inorg. Chim.Acto. 1972, 6,88. A . Mangia, M . Nardelli, C. Pelizzi. and G . Pelizzi. J . C . S . Dalton. 1972. 996.


239

I

OMe (73)

2,6-(Dibenzothiazol-2-yl)pyridine[10; (NNN)] forms the complexes [Co(NNN)X,] (X = Cl, Br, NCS, or NO,), [Co(NNN),](ClO4),,nH2O. and [Co(NNN),](BF4),,4H20. The chloride, bromide, iodide, and thiocyanate complexes are all five-co-ordinate and the nitrate complex is octahedral. All of these complexes have normal high-spin magnetic moments; however, the magnetic moment of the perchlorate is temperature dependent.72The tetrahedral complexes [CoX,(dpq)] and [CoX,(dmpq)] [X = Cl, Br, or I; dpq = (74; R’ = Me, R 2 = H, R3 = Me); dmpq = (74; R’ = R2 = R3 = Me)] have been i ~ o l a t e d . ~ ”

The complexes [CoX,L] (X = C1 or Br; L = dpmq; X = Br or I, L = dpdmq) are octahedral and [CoI(dpmq)] and [CoCl,(dpdmq)] are tetrahedral [dpmq = (74; R’ = Me, R 2 = R3 = H), dpdmq = (74; R 1 = R2 = Me. R 3 = H)] . 3 1.r. and magnetic data for [CoX,(pyrazine),] (X = C1, Br, or I) suggest that the structures of these complexes are sheet-like involving bridging pyrazine

(75) 391 392

D. F. Cotton and W. J. Geary, J . C . S . Dalton, 1972, 547. D. F. Cotton and W. J. Geary, J . Chem. SOC.( A ) , 1971, 2457.

(76)

240


ligands and trans-terminal halogen atoms rather than halogen-bridged, as had been proposed earlier. This has been confirmed by a crystal structure determination on the chloro-complex.393The complexes [CoX,L] and [CoX,L,] [X = C1. Br. or SO,: L = pyridazine. phthalazine (75), or benzocinnoline (76)] have been reported. The sulphate complex is octahedral, but the structures of the others could not be readily assigned.394 Irnidazole, pyrazole, and related Iigands. The structures of [Co(imidazole),]X,,nH,O [X, = (OAc),, n = 0; X, = CO,, n = 51 have been reported.39s Thermal decomposition of [Co(imidazole),]X, (X = C1, Br, I, or NO,) yields C o ( i m i d a ~ o l e ) + X , .The ~ ~ ~tetrahedral complexes [CoLnX2] (L = 2-methyl~ ~ the structure of the related imidazole. n = 4 or 6) have been s y n t h e s i ~ e dand complex [Co(2-Me-imidazole)4]N03.0.5EtOH has been reported.397 The latter contains a bidentate NO, group giving rise to very distorted octahedral geometry at the metal atom. The pseudo-octahedral complexes [CoLnX2] (L = N-n-butylimidazole, n = 1-6, X = C1. Br, I, or NCS) have been reported,'' as have [CoX,L,] (X = C1. Br, I. NCS. or NO,, L = 2-benzylbenziHowever, the 2midazole). which are dimeric with bridging X methjlbenzimidazole complexes. [CoL,X2] ( X = C1. Br. I. or NO,), adopt either tetrahedral (X = halide) or octahedral (X = NO,) geometry.399 2-(2'-Pyridy1)benzimidazole (L') and 2-(2'-pyridyl)imidazoline (L2) form the complexes Co(L'),X,. Co(L2),X2.and Co(L'),X, (X = C1, Br, I, or NCS). All are high-~pin.~" From the reaction of pyrazole (pz) or 3(5)-methylpyrazole (mpz) with COX, (X = NO, or NCS) in acetone-ethanol in various molar ratios, the complexes Co(pz),X,, Co(mpz),X,, and Co(pz),(NO,), can be isolated.76 Macrocyclic N-donor ligands. Complexes of the macrocyclic ligands ( 4 5 F (49) have been studied by cyclic voltammetry and the quasi-reversible or irreversible couples: COIL * Co"L 2 Co"'L were established.244 Physicochemical data on the Co", Ni", and Cu" chelates of 1,2-bis-(o-iminobenzylideneamino)-ethane (aben), -propane (abpn), -phenylene (abphen), and 1,3-bis(o-iminobenzy1ideneamino)propane (abtn) further support the earlier conclusions that they contain four-coplanar co-ordination. Electrochemical oxidation of these complexes gave uncharacterized products of copper and nickel; however, the crystalline complexes [CoLX] (X = C1, Br, or I) were readily isolated. These complexes are unique in being a paramagnetic Co"' species with N-donor ligands (perf= 2.4-2.7 BM). Square-planar structures are 393

394

395

396 397

398 399

400

P. W. Carreck. M . Goldstein, E. M . McPartlin, and W. D. Unsworth, Chem. Comm., 1971, 1634; M. Goldstein, F. B. Taylor, and W. D. Unsworth, J . C . S . Dalton, 1972,418. J. R. Allan, G . A. Barnes, and D. H . Brown. J . Inorg. Nuclear Chem.. 1971.33,3765. A Cadet, Compt. rend.. 1972, 274.C. 263: R. Strandberg and B. K. S. Lundberg, Acta Chem. Scond.. 1971, 25, 1767. P. S. Gomm, A. E. Underhill, and R.W. A. Oliver. J . Inorg. Nuclear Chem., 1972, 34, 1879. F. Akhtar, F. Huq, and A. C. Skapski. J . C . S . Dalton. 1972, 1353. M. V. Artemenko, K . F. Slyusarenko, and D. A. Stakhov, Russ. J . Inorg. Chem.. 1972. 17. 86. D. M. L. Goodgame, M. Goodgame, and G. W. Rayner-Canham, Inorg. Chim. Acta, 1972, 6. 245. D. M. L. Goodgame and A. A. S. C. Machado, Inorg. Chim. Acta, 1972,6, 317.


241

postulated and reaction with py gives [CoL(py)X]. In the case of L = aben, evidence is presented for an equilibrium between diamagnetic and paramagnetic species in donor solvents.401 NN'-Bis-(2'-formyl-4-nitrophenyl)-1,3diaminopropane and its ethylene analogue react with Co(OAc), and the compounds 1,2-diaminopropane, 1,3-diaminopropane, 1,2-diamino-2-methylpropane, 1,2-diaminocyclohexane, and 1,2-diaminobenzene to give the complexes (77).402 Compound (50) reacts with Co(OAc), to yield the planar 12n-macrocyclic complex Co[ MeHMe(en),] .247 R

(77) n

=

2 or 3; R = (CH,),, (CH,),,CMe;CH,, cyclohexyl, or o-phenylene

SO, interacts reversibly with tetraphenylporphinato-cobalt(1i) to give an adduct in which SO, acts as a donor; however, with 0,, a superoxide complex is formed.403 The binding of thioethers, thiolate anions, thiols, and nitrogen bases to cobalamins and cobinamides has been examined by e . ~ . r . ~The O~ equilibrium constant for the reversible binding of oxygen to cobalt(@ protoporphyrin-IX-dimethyl ester amine complexes has been determined in a study of model compounds for oxygen-carrying haemoproteins. Standard enthalpy changes of ca. - 10 kcal mo1-I and entropy changes of ca. - 5.5 e.u. were found, depending on the amine (amine = py, 4-t-Bu-py, or 1-methylimidazole) (cf: - 18.1 kcal mol- ' and - 60 e.u. for m y o g l ~ b i n ) The . ~ ~ reduction ~ of 1,19diethoxycarbonyltetradehydrocorrincobalt(I1) cations with a sodium film in THF under high vacuum gives both one- and two-electron reduction products, the former is a very stable Co' species and the latter a Co" complex with the two extra electrons located in ligand i ~ - o r b i t a l s . ~ ~ ~ Ligand field calculations on cobitlt(1r) phthalocyanine, vitamin B 2r, and its model compounds show the unpaired electron to occupy the d,, orbital in all cases.4o7 The effect of DMSO, py, imidazole, and CN- ligands on the e.s.r. spectrum of tetrasulphonated cobalt(r1) phthalocyanine has been studied. The neutral ligands give increasing changes in the spectra with increasing ligand basicity; however, in the presence of CN-, the Co" complex is no longer stable. Evidence is presented for an intramolecular oxidation-reduction reaction to the cobalt(1Ir)phthalocyanine anion. Attempts to prepare 1: 1 oxygen adducts 'O '02

' 0 3 *04 *05

407

R

B. M . Higson and E. D. McKenzie, J.C.S. Dalton, 1972,269. D. St. C. Black and P. W. Kortt, Austral. J. Chem., 1972,25, 281. B. B . Wayland and D. Mohajer, J.C.S. Chem. Comm., 1972,776. S . Cockle, H. A. 0. Hill, S. Ridsdale, and R . J. P. Williams, J.C.S. Dalton, 1972, 297. H. C. Stynes and J. A. Ibers, J. Amer. Chem. Soc., 1972, 94, 1559. N. S. Hush and I. S. Woolsey, J. Amer. Chem. SOC.,1972,94,4107. L. M. Engelhardt and M . Green, J.C.S. Dalton, 1972, 724.


242

were u n c u ~ c e s c f u lA. ~detailed ~~ study har been made of the i.r.. electronit. and e.s.r. spectra of a range of substituted dipyrromethane complexes of Co", Ni", and C U " . " ~ ~ Other N-donor ligands. The i.r. spectrum of CoC1,,2-(p-aminoazobenzene) has been examined and unidentate amino-group co-ordination is po~tulated.~" The phthalimide complex, [CoL,(MeOH),], has been isolated from the reaction of phthalimide (L) with cobalt(I1) salts in 70% aqueous methanol at pH 8.5.289 Hydrogen cyanamide forms the complex [CO(H,NCN),]SO,.~" 1,3,5-Triphenylformazan reacts with CoCI, in acetone to give a Co" complex and a tetrazolium salt as a mixture. 1-(2'-Carboxyphenyl)-3,5-diphenylformazone and its 2'-hydroxyphenyl analogue give 2: 1 complexes (ligand:CoCl,); however, there is again some ~ x i d a t i o n . ~ " 1,4-Di-(2'-pyridyl)aminophthalazineforms the dinuclear complexes (78) in which the cobalt atoms are tetrahedral. The magnetic behaviour of this type of complex is reported for the first time and shows the ions to be antiferromagnetically coupled. Similar data are reported for the known methyl- and dimet hyl-pyrazine c o m p l e x e ~ . ~Co" forms octahedral complexes with 5-o-

(78) X = C1, Br, or I

chlorophenyl-, 5-p-chlorophenyl-, 5-p-methoxyphenyl-, 5-p-chlorobenzyl-, and 5-phenyl-tetrazole. 1.r. evidence indicated that the 1-nitrogen atoms of the tetrazole rings are not p r ~ t o n a t e d'. ~Bis-(N-butylpyrrole-2-carboxa1dimino)cobalt(I1) has distorted tetrahedral [CoN4] c o - o r d i n a t i ~ n The . ~ ~ ~1,1,4-trimethylpiperazinium cation, L, forms the complexes [CoLX,] (X = C1, Br, or I): however. the donor properties of the cation are weak, and under slightly ~ thermal stability of different conditions (L+)2(CoX4)2-is f ~ r r n e d . ' The Na[Co(SO,)(dmg),L]H,O (L = acetamide. urea. thiourea, selenourea, dimethylacetamide, thioacetamide, thiosemicarbazide, or diphenylthiourea) complexes has been 408 409 410

L . D. Rollrnann and S. I . Chan. hi or,^. Chem.. 1971. 10. 1978. Y . Murakama. Y. Matsuda, and K. Sakato, Inorg. Chem., 1971, 10, 1728, 1734. L. V. Konovalov. I. S. Maslennikova, and V. N. Shemyakin, Russ. J . Inorg. Chem., 1971, 16, 1528.

4"

412 413 4'4

415

'Ih

W . C. Wolsey, W. H. Huestis, and T. W. Theyson, J . h o r g . Nuclear Chem., 1972, 34. 2358. R. Price,J. Chem. SOC. ( A ) , 1971, 3379. A. B. P. Lever, L. K. Thompson, and W. M. Reiff, Inorg. Chem., 1972, 11, 104. P. Labine and C. H. Brubaker, J . Inorg. Nuclear Chem.. 1971, 33, 3383. C. H. Wei, Znorg. Chem., 1972, 11, 1100. G. P. Syrtsova, N . W. Cheban, and V. N. Shafranskii, Russ. J. Inorg. Chem., 1971, 16, 1619.


243 0-Donor ligands. [Co(MeOH),]X, (X = ClO,, BF,, or NO,) complexes have been prepared by the reaction of hydrated metal salts with trimethylorthoformate; [Co(MeOH),SO,] was also isolated.81 CoC1,,4MeOH. is isomorphous with its nickel analogue.234The trialkylamine N-oxides, Et,NO and Pr,NO, form two types of cobalt complex, [CoL,X,] (X = C1, Br, I, or SCN) and [CoL,] (ClO,),, both of which are tetrahedral. Addition of Pr,NO to [Co(Pr,NO),X,] gives [Co(Pr,N0),I2+. However, addition of Et,NO to [Co(Et,NO),X,] or [ C O ( E ~ , N O ) ~ ] gives ~ + the five-co-ordinate cation [Co(Et,N0)J2 +.,I7 2,6-Lutidine N-oxide forms the complexes [CoL,X,] (X = C1, Br, or I) which are tetrahedral in the solid state and in nitromethane, methylene dichloride, and the 2,6-luNO-CH2C1, mixed solvent system. In 2,6-luNO-MeN02, the iodide forms [CoL,I]I and in pure 2,6-luNO, [CoL,]I,. The thiocyanate complex [CoL,(NCS),] is five-co-ordinate in the solid state with one bridging NCS group, and pseudo-tetrahedral in CH,CI, and MeNO,: however, the structure of CoL,(ClO,), could not be unequivocally assigned in the solid state, although in 2,6-luNO-MeN02 or pure 2,6-luNO, [CoL,]'+(C10,); is formed.,' Cobalt(I1)bis-phenylglycollateis formed from the reaction of phenylglycollic acid and Co(OAc), in MeOH,,, and the complex CoA,xM,O (A = 3-ketoglutarate, x is uncertain) has unidentate carboxylate co-ordina(55) forms the polymeric octahedral t i ~ n . 'Hydroxymethylenenorcamphor ~ compounds [CoL,], [CoL2],0.5H,O, and [ C O L , ( ~ ~ ) H , OThe ] . ~i.r. ~ ~spectra of the maleates, [Co(mal)],3H2O and H,[Co(mal),],4H20, suggest that the Co-0 bond has less covalent character than the corresponding oxalates or m a l ~ n a t e s . ~ 'The thermal decomposition of [Co(glycinate),] and its bisammine adduct has been studied.,,' Co" complexes of d-, 1-, and dl-mandelic acid, Co(O,C.CHOH* Ph),.,'l and of benzilic acid. [C0(benzilate),],2H,O.~~~ have been reported. [Co(acac),] reacts with bromine in CH,Cl, to yield the new complex [ C o ( a c a ~ ) B r , ] , ~which ~ ~ " can also be prepared from anhydrous CoBr, and acac. However, the reaction of [Co(acac),] with bromine gives either CoBr, and y-Br-acac or [Co(acac)Br], depending on the temperature. [Co(acac)Br], has tetrahedral co-ordination with bridging acac groups.42 The complexes [Co(acac),L] (L = RNH,, with R up to C,, when saturated, up to C,, when unsaturated) have been isolated; however, the long alkyl or alkenyl chains have no effect upon the properties of the complex except in altering the solubilities and melting points.,,, The structure of [Co(acac),(NH,-cyclohexyl)] has been determined. It is a centrosymmetric dimer consisting of two octahedra

'

D. W. Cunningham and M. 0. Workman, J . Inorg. Nuclear Chern., 1971,33, 3861. D. W. Herlocker, Inorg. Chim. Acta, 1972, 6 , 211. 4 1 9 D. N. Sathyanarayana and V. V. Savant, Z. anorg. Chem., 1971, 385,329. 4 2 0 M. A. Bernard and N. F. Decker, Bull. SOC.chim. France, 1972, 1288. 4 2 1 A. Ranade, Z. anorg. Chem., 1972,388, 105. 4210 Y. Nakamura, M . Gotani, and S. Kawaguchi. Bull. Chem. SOC. Japan, 1972,45,457. 4 2 2 Y. Nakamura, N . Kanehisa, and S. Kawaguchi, Bull. Chem. SOC. Japan, 1972,45,485. 4 2 3 D. A. Fine, Inorg. Chem., 1971, 10, 1825.

417

418

244


sharing a common edge and containing two chelating and two bridging acac The six-co-ordinate complexes [CoL,] and [CoL,Bn] (B = H,O, n = 2 or 3: B = EtOH or py, n = 2: LH = nitroacetone, l-nitrobutan-2-one, 3,3dimethyl-1-nitrobutan-2-one, a-nitrodeoxybenzoin, 2-nitrocyclohexanone, or 3-nitrocamphor) have been prepared. The ligands are all chelating uia the .~~~ monosulphcarbonyl group and one oxygen of the n i t r o - g r ~ u p 1,4-Dithiane oxide (DTMSO) forms the complexes [COX,(DTMSO)~] (x = Cl, Br, I, NO,, or NCS: n = 2, 3, or 6).91The i.r. spectrum of the Co(TMS0);' cations is very similar to that of the DMSO analogue." The complexes [CoL,X,] (L = tetramethyl- or tetraethyl-dithio-oxamide, X = C10, or Fe"'C1,) have been identified. 8 8 A study of Co" in a LiN0,-KNO, melt indicates a distorted octahedral stereochemistry for the metal ion.426[Co3(OH),(S0,),],2H,O has a structure consisting of infinite chains of Co-0 octahedra sharing a common edge. These chains are linked by sulphate groups and additional Co-0 octahedra to give a three-dimensional network, the structure being quite unlike most metal(r1) hydroxides. A thermal study has been made of the compound.427 [(RSO,),Co(OH,),] reacts with bipy at 50°C in water to give [ICo(bipy),](RSO,), which, when heated in acetone, gives [RS(O)O],[Co(bipy),] and [RS(0),][C0(bipy),].~~~ The thermal decomposition of NH,CoPO,,H,O has been studied.428Phenylphosphonic acid reacts with Co" to give polymeric compounds with bridging phosphonate groups,98 and phenylarsonic and o-arsanilic acids (L) give the octahedral CoL,xH,O (x = 0.5, 0, or 1) compound~.~, (n~= The Ph,PO complexes [ C O ( P ~ ~ P O ) ~ ] ( B F ) , 4, tetrahedral; n = 5, square-pyramidal: n = 6, octahedral) have been The complexes [Co{C,H,P(O)(NMe,),},]X, ( X = C10, or BF,) and [Co{PhP(O)(NMe,)2},JC12 have been prepared and a comparison made between the co-ordinating ability of this ligand, hexamethylphosphoramide and Ph3P0.96 (E = P or As: n = 2 or 4) reacts with Co" salts to give Ph2E(0)(CH,),IE(O)Ph, [(Ph,E(O)(CH,),E(O)PhZ)Co(NO,),], (E = P or As), [(Ph,E(O)(CH,),E(O)P~,],CO(H,O),](C~O~)~ (E = P or As, n = 2; E = P, n = 4), and [(Ph,As(0)(CH2)4As(O)Ph2}Co](C10,),,2H,0.The first two complexes are octahedral and the third tetrahedral.430 The complexes [CoL,](ClO,), [IL = R,P(O).OP(O)R,, where R = Me, Et, or Ph] are six-co-ordinate with chelating ligands but are less stable than the corresponding octamethylpyrophosphoramide complexes.43' The related complexes of (79), [CoL3](C10,), 424 425

426 427

428

429 430

"I

J. A . Bertrand and A. R. Kalyanaraman, Inorg. Chim. Acra, 1971, 5 , 167. D. Attansio, I. Collamati and C. Ercolani, J.C.S.Dalton, 1972, 772. S . V. Volkov and N . I. Buryak, Russ.J . Inorg. Chem.. 1972, 17, 93. E. Dubler and H . R. Oswald. Hels. Chim. Acta. 1971, 54, 1621, 1628. L. N . Shchegrov, V. V. Pechkovskii. A. G. Ryadchenko. and R. Y. Melnikova, Russ. J. Inorg. Chem.. 1971, 16, 1622. S. S. Sandhu and G. K. Sandhu, J . Inorg. Nuclear Chem., 1972,34, 2249. S. S . Sandhu and R. S. Sandhu, J . Inorg. Nuclear Chem., 1972, 34, 2295. M . D. Joesten and Y. T. Chen, J . Inorg. Nuclear Chem., 1972, 34,237.


245

also have octahedral stereochemistry with 0- rather than N - ~ o - o r d i n a t i o n . ~ ~ ~ The complexes of hexamethylphosphoramide (HMPA) and nonamethylimidophosphoramide (NIPA), [Co(HMPA),](CIO,),, [Co(NIPA),](ClO,),, and Co(NIPA)SO, have been i ~ o l a t e d , ~ and ' . ~ ~the ~ polarized crystal electronic spectrum of [Co(octamethylpyrophosphoramide)3](C10,), has been examined in 0

0

I R-P-0-P-R I

I I

Me,N (79) R

=

NMe,

Me, Et, or Pr'

Crystalline [CoBr2(dioxan),],4H,0 has been prepared, and spectral measurements suggest a trans octahedral stereochemist ry. Thermal decomposition of this complex shows loss of water and dioxan yielding ultimately CoBr,.82 A convenient method for the preparation of [Co(NH20H),Cl,] involves reaction of CoCO, and NH,OH,HCI in boiling water.87 A series of tungstates have been prepared by mixing aqueous solutions of either Co2+ or Ni2+ and K,WO, in the presence of oxidizing agents.435 S- and Se-donor ligands. The e.s.r. and electronic spectra of [Co(sacsac),] and [Co(sacsac),L] (sacsac = dithioacetylacetonate, L = py or piperidine) have (n = 2 or 3) in been and a polarographic study of [Co(~acsac)~] acetone has shown the complexes to have a well-defined capacity to accept one or two electrons in a reversible stepwise manner. The magnitude of the potentials and their reversible nature suggest that isolation of cobalt-sacsac complexes of low formal oxidation states should be possible.437 Co" complexes of 1,5-bis-(2-methylmercaptoethylthio)pentaneare both hydrated and polymeric, and thermal decomposition in air or nitrogen leads to oxidition to ~ ~ 1.3 114 1 Ethylenethiourea (etu) and tetramethylthiourea (tmtu) form the complexes [Co(etu),](NO,), and [Co(tmtu),](ClO,),, which are tetrahedral. and [Co(etu),(NO,),] and [Co(tmtu),(NO,),] which have distorted octahedral - 1,l-diethyl~ o - o r d i n a t i o n . , 3-Diphenylphosphinothioyl-l-phenylthiourea, ~~ thiourea, and -1,l-dimethylthiourea form complexes with Co" in which the iigands are bidentate.439 Polymeric dithiophosphonate complexes of the type (80) have been prepared. The cobalt complex is tetrahedral and the nickel complex planar and both 432

433 434 435

436 437

439

M. D. Joesten and Y . T. Chen, Inorg. Chem., 1972,11,429. M. W. G. De Bolster and W. L. Groeneveld, Rec. Trav. chim., 1972, 91, 185. R. A. Palmer and C. R. Taylor, Inorg. Chem., 1971, 10,2546. M. V. Mokhosoev, N. A. Taranets, and M. N. Zayatis, R u n . J. Inorg. Chem., 1971, 16, 1012. K. M. Erck and B. €3. Wayland, Znorg. Chem., 1972, 11, 1141. A. M. Bond, G. A. Heath, and R. L. Martin, Inorg. Chern., 1971, 10, 2026. E. C. Devore and S . L. Holt, J . Inorg. Nuclear Chem., 1972, 34, 2303. I . Ojirna, T. Onishi, T. Iwarnato, N. Inamoto, and K.Tamura, Bull. Chem. SOC. Japan. 1971, 44, 2150.


246

complexes have been used as chromatographic supports in the separation of amines."' The cobalt chalcogen compounds [Co(SSePPh,),] have been prepared. The chalcogen groups are bidentate.44' The complexes [( Y PPh, CH*PPh;Y;,Co] ( Y = S or Se) have been obtained by deprotonation of

(80)R

=

MeOC,H,; M = Co or Ni

(Ph2PY)2CH2with Bu"Li followed by addition of metal halogeno-complex anions. Both compounds are tetrahedral and the Se complex is the first example of a tetrahedral [CoSe,] core.2hoThe tetrahedral [ C O ( S ~ A S M ~ , ) , ] 'and ~' [ C O ( W O S , ) , ] ' - ~ ~have ~ been reported, the latter having only co-ordinated sulphur atoms. P-Donor ligands. A study has been made of the magnetic properties of [CI,M(PPh,),] (M = Co or Ni) in order to evaluate the dipolar contributions to the isotropic 'H n.m.r. shifts of the phenyl protons,443and a 'H n.m.r. study of the pseudo-tetrahedral [LJPnMBrn](M = Ni, n = 1 or 2: M = Co, n = 0, 1, or 2; L = MePh,P) suggests that (d-d)n-bonding present in the zerovalent complex constitutes the dominant spin-transfer mechanism. whereas in the bivalent species (d-d)n-bonding is unimportant and spin transfer occurs mainly via o-non-orthogonality. In the univalent complexes, spin transfer probably occurs by both mechanisms. although (d-d)x-bonding is less important than in the zerovalent The complexes [CoX,(Me,PPMe,),] (X = C1, Br, or I) have been isolated.2h' Mossbauer and X-ray studies on red[Co(dpe),Cl]SnCl, and green [C~(dpe)~Cl]SnCl,,PhCl(dpe = 1,2-diphenylphosphinoethane) show the red form to hate a square-pyramidal cation with apical chlorine and the green form to have a trigonal-bipyramidal cation with two apical phosphorus atoms."45 The phosphine (Ph,PCH,CH,),PPh (Pf-Pf. Pf) forms the complex [CoCI,( Pf. Pf-Pf)], which is five-co-ordinate in the solid but decomposes in solution.2s whereas the related phosphines, (Ph,PCH,CH,),P [P(Pf),] and Ph,PCH,CH2P(Ph)CH,CH,P(Ph)CH2CH,PPh, (Pf. Pf. Pf-Pf) both form the Gte-co-ordinate cations [LCoCI] + . 2 5 Howeter. 440 441

442 443 444 445

W. Kuchen, J. Delventhal. and H. Keck, A n g w . Chem. Infernal Edn.. 1972, 11.435. P. Christophliemk. V. V. K. Rao. I . Tossidis. and A. Muller, Chem. Ber., 1972, 105, 1736; A . Miiller. V. V . K . Rao. and P. Christophliemk. J . Innrg. Nrrclear Chem.. 1972. 34, 345. A. Muller and H . H. Heinsen, Chem. Ber.. 1972. 105. 1730. W. D e w . Horrocks and E. S . Greenberp, Inorg. Chem.. 1971, 10, 2190. G. N . LaMar, E. 0. Sherman, and G . A. Fuchs, J . Coord. Chem.. 1971, 1, 289. J. K . Stalick. D. W. Meek. B. Y . K . Ho. and J. J. Zuckermann. J.C.S. Chem. Comm., 1972,630.


247

(Ph,PCH,CH,),PCH,CH,P(CH,CH,PPh,), [P2(Pf),] reacts with CoCI, under identical conditions to give the Co"' complex [{ P,(P~),)COCI~]CI.~~ The structure of [Co(qp)CI]Cl [qp = tris-(0-diphenylphosphinopheny1)phosphine] shows distorted trigonal-bipyramidal co-ordination. and arguments have been presented that it may show a Jahn-Teller effect.446The five-co-ordinate complex [Co((Me,N),PF),]I, can be obtained from the reaction of the ligand and CoI,. In CH,Cl, or benzene solutions, an equilibrium is established between the low-spin five-co-ordinate complex and a high-spin pseudo-tetrahedral complex of the type C O L , I , . ~ ~CoBr, ' forms the zwitterion complex t

[(PhCH,)Ph,PC=ClPh,P-+CoBr;] and Ph,PC=CPPh, reacts with CoBr, and Et,NBr to give E~,N[B~,COPP~,C=CPP~,].~~~ The reactions of 1,2,5-triphenylphospole, its oxide. sulphide, and selenide with Co" halides have been ,Mixed donor ligands. The reaction of the 1,2,6-isomer of [Co(OC,H,which conNH2),],3H,O with Co" salts gives [Co,(OC,H,NH,),X,],nH,O, tains three Co"' ions and one Co" ion.449N-Hydroxyethylethylenediamine (hen) forms the series of complexes [Co(hen)X,] (X = C1, Br, or NCS).450NNN"'N"'-Diglycylethylenediaminetetra-acetic acid (H,L) forms the new cobalt(i1) chelate [CoLI2-. The complex acts as an oxygen carrier, one mole of oxygen being absorbed per two moles of complex, and potentiometric data indicate that two hydrogen ions per ligand are released on oxygenation giving [Co,02(L-2H)2]8-.451The complexes [CoL,](NO,), and [CoL,(NO,),],nH,O (L = 2-pyridone) have been i~olated.'~The octahedral complex [Co(pan),] and the tetrahedral complex [Co(btan),] [pan = 1-(2'-pyridyl)-2-azonaphthol(81): btan = 1 -(2'-benzothiazo1yl-2-azonaphtho1(82)1 have been synthesized. as have their Nil*and CU" analogues. However, the stereochemistry of the nickel and copper complexes is uncertain.452

(81)

446 447 448

449

450 451

452

(82)

T. L. Blundell and H. M . Powell, Acta Cryst., 1971, B27,2304. T. Nowlin and K. Cohn, Inorg. Chem., 1972, 11, 560. R. C. Taylor and R. A. Kolodny, Inorg. Nuclear Chem. Letters, 1971, 7, 1063. A. Geransenkova and V. V . Udovenko, Russ. J . Inorg. Chem., 1972, 16, 232. M . N . Hughes, M. Underhill, and K. J. Rutt, J.C.S. Dalton, 1972, 1219. R. Nakon and A . E. Martell, Inorg. Chem., 1972, 11, 1002. T. A. Zhuchenko, L. I. Kuznetsova, V. A . Kogan, A. D. Garnovskii, 0. A. Osipov, M . V. Gorelik, T. K. Gladysheva, V. A. Alekseenko, and T. A. Zayakina, Russ. J . Znorg. Chem., 1971, 16, 1157.

248


The new ligand, 2.3-di-(2-pyridine N-oxide)quinoxaline (83) has been prepared and the complexes [CoCl,L],l.SH,O, [CoBr,L],H,O, and [CoI,L],H,O isolated from its reaction with the appropriate cobalt@) salt in ethanol. All three complexes are tetrahedral.453

N

By grinding together Co(N0,),.6H20 and urea in a 1:4mole ratio, together with a few drops of methanol, and repeating the process until all the water of hydration is driven off. [Co(urea),](NO,), is formed. The complex contains ~'~ also forms complexes both uni- and bi-dentate urea l i g a n d ~ . N-Hydroxyurea with C O " . ' ~ 'The mono- and bis-ligand complexes of Co" with 1,lO-phenanthroline-2-carboxamide are all six-co-ordinate and i.r. evidence indicates that the amide group is 0-bonded.262The octahedral comdex [CoL,Cl(H,O)] (L = 8-amino-7-hydroxy-4-methylcoumarin) has been reported.322 l-oxide)cobalt(~~) The structure of bis-( 1-methyl-3-o-chlorophenyltriazene(84) is unusual in that it contains two terdentate ligands giving rise to the rare [CoN,O,Cl,] core with no co-ordinated halide ions: however, the C1 atoms are only weakly co-ordinated (Co--CI = 2.98 A).455This and related complexes are prepared by treating the appropriate diazonium salts with substituted hydroxylamines. and the treating the product, in alcoholic solution, with with Co(OAc),. The related bromo-complex is also octahedral, but the iodocomplex is planar in the solid state and pseudo-tetrahedral in

(84) 4s3 454

4s5 456

M . Tong and D. Ci. Brewer, Cairad. J . Chem.. 1971, 49. 3425. P . S. Gentile, P. Carfango. S. Haddad, and L. Campisi. Inorg. Chim.Acta, 1972, 6, 296 G. L. Dwiredi and R. C . Srivastava, Acra Crysr., 1971. B27, 2316. P. S. Zacharias and A . Chakravorty. htorg. Chem.. 1971. 10, 1961.


249 Spectral evidence4' indicates an equilibrium between tetrahedral and octahedral Co" in NN-dimethylacetamide and the equilibrium constant for [Co2 +(tet)]/[Co2 '(oct)] is reported at various temperatures. The complexes of acetylhydrazine (A), [CoAJX, (X = C1 or Br) and [Co(NCS),A,]H,O and the tri-N-deuterio-ana10gue[Co(NCS),(Ad3),]D20 have been isolated and examined by i.r.'02 Cationic complexes of N-acyl hydrazines have been isolated with ligands in their keto-form, RCO. NH-NH,; however, the ligands also react in their en01 form, RC(0H) = NNH,, forming neutral complexes (R = Me, Pr", Pri, or Ph).458 A 'H and 31Pn.m.r. study of thiamine pyrophosphate in the presence of cobalt(~r)or nickel(1r) indicate that the T P P is bonded to the metal via pyrophosphate and the pyrimidine group,459in a similar manner to ATP-M2+ complexes. The structures of the 1: 1 complex formed between 1,3,5-trinitrotoluene and bis-(N-t-butylsalicylideneiminato)cobalt(r~)and its nickel(I1) and copper(I1) analogues show all three compounds to be isomorphous and to be formed from pairs of donor ML, molecules and an acceptor TNT molecule. The TNT interacts with only one of the ligand molecules in each complex and the complex has a flattened [M0,N2] tetrahedral core 460 Complexes of HO(3-Pr')C6H3CH=N(CH2)nN=CHC,H3(3-Pri)OH ( n = 2-7) with Co" have been prepared. Spectral and magnetic measurements show that, for n = 2, the complexes are either low-spin square-planar in the solid and in CH,Cl, or possibly have extensively flattened tetrahedral geometry. For n = 4-7, the complexes are pseudo-tetrahedral in both the solid and in non-donor solvents. All the complexes are monomeric in non-donor solvents, and in pyridine they increase their co-ordination number to achieve pseudo-octahedral struct u r e ~ . The ~ ~ ' new complexes [Co(salen)B] (B = imidazole, 2-methylimidazole, benzimidazole, 5,6-dimethylbenzimidazole, 3-iodoimidazole, or 3,Slutidine) and [Co(saloph)B] [saloph = NN'bis(salicy1idene)-o-phenylenediamine, B = imidazole] have been isolated and show room temperature magnetic moments in the range 1.9-3.5 BM; these results are interpreted as arising from a 4A"-2A' spin equilibrium. The anomalous temperature dependence of the magnetic susceptibility of some of the salen complexes is that expected for such an equilibrium.462 TCNE reacts with [Co(acacen)] in the presence of py to give an air-sensitive product in both green and purple forms. These are isomers of [Co(acacen)py],,TCNE and structures (85) and (86) are proposed. In the absence of py, polymeric Co(acacenkTCNE is formed.463 N-Hydroxyethylnaphthalideneimine forms the tetrahedral complex [CoL,], for which structure

'

457 458

459 460 461

462 463

V. Gutmann, R. Bernan, and W. Kerbel, Monatsh., 1972, 103,764. J. F. Alcock, R. J. Baker, and A. A. Diamantis, Austral. J. Chem., 1972, 25,289. W. D. White and R. S. Drago, Znorg. Chem., 1971, 10,2727. E. E. Castellano, 0. J. R. Hodder, C. K. Prout, and P. J. Sadler. J. Chem. Soc. ( A ) , 1971, 2620. M. Hariharan and F. L. Urbach, Inorg. Chem., 1971, 10,2667. L. G. Marzilli and P. A. Marzilli, Znorg. Chem., 1972, 11, 457. A. L. Grumbliss and F. Basolo, Znorg. Chem., 1971, 10, 1676.


250

(87) is suggested. This differs from that of the manganese complex [see (13), p. 1921 in that the hydroxyl oxygen is not co-ordinated in this case."'

9

7'

\co

\ /

co NC

I\

MCN

NC

CN

\ /

co

0' '

CO

\

( 8 5 ) purple isomer

(87)

(86) green isomer

(88)

The potentially terdentate ligand. thiodiethanol(88),forms 1 :1 complexes and 1:2 complexes with CoCl,. The former are five-co-ordinate and the latter octahedral. l o 9 1 :1 Complexes of Co" and diethylenetrithioacetic acid, ethylenedithiodiacetic acid, and ethylidenetetrathiotetra-acetic acid have all been reported.' l o - l 1 Potassium monothiobenzoate reacts with an equimolar quantity of CoSO, in aqueous solution to yield green crystals of the pseudotetrahedral dinuclear complex [Co,(SOCPh),], which contains both bidentate and bridging thiobenzoate l i g a n d ~ . ~ ~ , The tetrahedral Co" complex, [CoL,Cl,] (L = 2-pyridyldiphenylphosphine), has been isolated.465 Ph,P(CH,),N(Me)(CH,),N(Me)(CH,),PPh, (pnnp) forms fke-co-ordinate complexes of gencral formula [Co(pnnp)X]Y (X = halogen or pseudohalogen, Y = Br, I, ClO,, BPh,, or PF,) which are lowspin and square-pyrimidal in stereochemistry. The corresponding Co" complexes with tripod ligands have an N,P, donor set, are high-spin, and have a distorted trigonal-bipyramidal geometry, and it is suggested that squarepyramidal geometry favours low-spin C O " . The ~ ~ structure ~ of [Co(N(CH,CH,PPh,),)I]I, which is also low-spin, also shows it to have distorted square-

'

464

465 466

M. L. Luciani and C. Furlani, Inorg. Chem.. 1971, 10, 2614. H. G . Ang, W. E. K o a . a n d K . F. Mok, Inorg. Nuclear Chem. Letters, 1972, 8, 829. L. Sacconi and A . Dei, J . Coord. Chem.. 1971, 1, 229; A. Bianchi, C . A. Ghilardi, C . Mealli,and L. Sacconi. J.C.S. Cheni. Comm., 1972. 651.

Elements of the First Transition Period

251

pyramidal geometry with one phosphorus atom at the apex. This is an unusual example of a symmetrical tripod ligand giving rise to square-pyramidal ~ o - o r d i n a t i o nThe . ~ ~geometry ~ of [CoCI((Et,NCH2CH2),NCH2CH2PPh2)]C10, is distorted trigonal-bipyramidal, but is perhaps better considered as a capped tetrahedron, the central N atom of the ligand being unusually distant from the metal at 2.30 A.468 The high-spin complex [CoCI((Ph,PCH,CH,),NCH,CH,OMef]PF, (CINP,O donor set) also shows a distorted trigonalbipyramidal geometry with a tendency towards a tetrahedron: this geometry appears to favour the spin-free state.4698-Quinoldiphenylphosphine forms the complexes [LCoXIX (X = C1 or Br), which show a tetrahedral-five-co-ordinate equilibrium.264 COX, reacts with liquid Me,NPF, to yield [CoX,L,] (X = Br or I); however, no reaction was observed when X = F or CI. The complexes are five-co-ordinate (pefr= 2.5 BM) and probably of intermediate geometry, although it is not certain whether they are N- or P-b~nded.,~' The cobalt(I1) complexes of (89), [CoL(H,O),]Cl and [CoL(OH)(H,O),] have been prepared471and both show a lower value for their magnetic moment than that expected for high-spin Co".

Diacetylmonoximeselenosemicarbazone (H,dseo) forms the high-spin complex [Co(H,dseo),]Cl,. The ligand is terdentate in this octahedral complex giving rise to a [CoN,Se,] core. S-Methyl-N-isopropylidenedithiocarbazate(N-SH) forms Co(N-S),, which is tetrahedral326 and the potentially terdentate ligands, r-N-methyl-S-methyl-~-N-(2-pyridyl)methylenedithiocarbazate (L') and its 6-methylpyrid-2-yl analogue (L2)form [CoL'X,] (X = C1, Br, I, or NCS), [CoL2),](BF,),, and [CoL2][CoX,] (X = C1, Br, or NCS).' 12. 2 6 7 The ligands TIB-N-tBu (90), TIB-DPT, and TIB-MeDPT (91) have been prepared, together with the cobalt(I1)complexes [Co(TIB-N-tBu),](tetrahedral) and CoL (L = TIB-DPT or TIB-MeDPT, both fi~e-co-ordinate).~~, The complexes of 2-thiophenaldoxime (92),[CoCl,L,], have been isolated.473 Spectral and magnetic studies on the tetrahedral dithioacetamide (tac) complexes [Co(tac),X,] (X = C1, Br, or I) and [Co(tac),](ClO,), show the ligand 467 468 469

470 471

4'2

473

C. Mealli, P. Orioli, and L. Sacconi, J . Chem. SOC.( A ) , 1971, 2691. P. Dapporto and G. Fallani, J . C . S . Dalton, 1P72, 1498. P. Dapporto, G. Fallani, and L. Sacconi, J . Coord. Chem., 1971, 1.269. T. Nowlin and K. Cohn, Inorg. Chem., 1971, 10, 2801. M. P. Swami, D. K. Rastogi, P. C. Jain, and A. K. Srivastava, Israel J . Chem.. 1971,9,653. I. Bertini, L. Sacconi, and G. Speroni, Inorg. Chem., 1972, 11, 1323. M. P. Coakley and M. E. Casey, J . Inorg. Nuclear Chem., 1972. 34, 1937.

252


to be S-bonded in all cases.474Isothiazole [it (93)] forms the cqmplexes [Co(it),2,1,3-benzothiodiazole, 2,1,3X,] (X = CI or Br) and [Co(it),(NCS), benzoselenodiazole. and their derivatives form [CoLX,] (X = Cl or Br), which are octahedral, and [CoCl,L, ,,I which is an ~ c t a h e d r a l - p o l y m e r . ~ ~ ~

(92)

I

I

SH

N =C,H

CH =N

(90)

(93)

(91) R = H, TIB-DPT

R = Me, TIB-MeDPT

Other Compounds. Adsorption of MeNC into a cobalt(I1) zeolite at - 196°C was followed by e.s.r. spectroscopy, and the presence of low-spin [Co(CNMe),]” and [Co(CNMe),]’+ complex cations d e r n o n ~ t r a t e d This .~~~ work represents one of the few successful attempts to produce well-characterized transition-metal complexes in a zeolite framework. Addition of NaCp to CoCl, and [(B,C2H JCoCp], previously reduced with sodium naphthalide gives a new bimetallic complex, for which structure (94) is

.= BH

CH v Cobalt(rI1).-Complexes. Ammiize complexes. Optical activity can be induced in the complexes [Co(NH3),l3+ and [Co(en),I3+ by means of outer-sphere association with chiral anions, e.g. ( +)-tartrate. Circular dichroism is observed in the d-d bands of the cations and it is suggested that this is due to (a) direct interaction between the chiral anion and the-metal d-orbitals and (b) the preferred conformation adopted by the inner-sphere ligands in the presence of a helical outer-sphere ligand.478 474

475 4-6

477 4’8

K. K. Chatterjee, Inorg. Chim. Acta. 1972, 6 , 8. M . E. Peach and K. K. Ramaswamy. Inorg. Chim. Acta, 1971, 5 , 445. E. F . Vasant and J . H . Luneford, J.C.S. Chem. Comm., 1972, 830. W . 5 . Evans and M . F. Hawthorne, J.C.S. Chem. Comm.. 1972, 611. B. Norden, Acra. Chem. Scand., 1972, 26,1 1 .

Elements of the First Transition Period

253 Solid-phase deaquation of C~~-[CO(NH,),(H,O),]~has been studied. The sulphate trihydrate forms the dinuclear sulphate-bridged complex cis-cis[(SO,)(NH,),Co(p-SO,)Co(NH,!,(SO,)], which is unstable in air and rapidly aquates to cis-[Co(NH,),(H,O)SO,] +. The suggested mechanism for this reaction is: +

, ,

Deaquation of cis-[Co(NH),( H, 0),1(SeO,), ,3H, 0, cis- [Cr(NH 3)4( H O),] (S04),,3H20, and cis-[Co(NH,),(H20)S04]2(M04),3H,0 (M = S or Se) yields structurally analogous dinuclear However, deaquation of cis-[ Co(en),(H,O)SO,] Br and the complexes cis-[Co(NH,),( H, O)SO,]X (X = C1, Br, NO,, CIO,, BF,, or iPtC1,) gives bidentate sulphato-complexes of the type [Co(en),SO,]Br and [Co(NH,),SO,]X (X = ClO,, BF,, or tPtC1,) or the unidentate sulphato-complexes cis-[Co(NH,),(SO,)X] (X = C1, Br, or Dehydration of [Co(NH,),(H,O),]Cl, in vacuum at 20°C yields trans-[Co(NH,),Cl,]. The cis-isomer and cis-[Co(NH,),Br,] are obtained by thermal dehydration of [CoX,(H,O)(NH,),]X. Reaction of [Co(NH,),(H,0),I3+ with Cl,CCO, or NCS- gives trans-[Co(O,CCCl,),(NH3),],2H,O and ~~~~~-[CO(NCS),(NH,)~],O.~H,O, re~pectively.~~' The structures of [Co(NH,),(SCN)]Cl,,H,O and [Co(NH,),(NCS)]Cl, have been determined. The former contains a Co-SCN group which is bent (angle at sulphur = 105") and no structural trans effect was observed. The latter has a linear Co-NCS The structure of [Co(NH,),CO,]Br has been reported with a higher refinement than previously achieved and the report of a trans effect of CO, on the Co-N bond lengths was found to be erroneous. The reported dimensions are Co--N(trrrns) = 1.97 not 2.03 A: Co-N(cis) = 1.98 and 1.93 The charge-transfer spectra of [Co(N,)CO,]' cations [N, = (NH,),, (en),, (pn),, or (tn),] and the anions [Co(NH,),(CO,),] - and [CO(CO,),]~- have been reported, together with an examination of the N-H and C--0 stretching frequencies. Covalency factors have been evaluated and hydrogen bonding has also been A simplified preparation of [Co(NH,),LI3+ (L = en or pn) is achieved by the reaction of L with [Co(NH,),(NO,),](NO,) in DMS0.4s5Two geometrical

"' E. P. Hertzenberg and J. C . Bailar, Znorg. Chem., 1971, 10, 2371. 482 483 484

485

E. P. Hertzenberg and J . C . Bailar, Znorg. Chem., 1971, 10, 2377. M. Linhard, H. Siebert, B. Brietenstein, and G. Tremmel, 2. anorg. Chem., 1972, 389, 11. M. R. Snow and R. F. Boomsma, Acta Cryst., 1972, B28, 1908. M. R. Snow. Austral. J . Chem., 1972, 25, 1307. V. S. Sastri, Inorg. Chim. Acta, 1972, 6 , 264. H. Yoneda. M . Mato, and K. Tamaki. Bull. Chem. SOC.Japan, 1971,44, 2863.


254

isomers of [CoCl(NH,)(tren)]C1, [tren = N(CH,CH,NH,),] have been obtained in their pure forms after careful decomposition of [(NH,),(tren)Co. OO.Co(tren)(NH,),]Cl, in concentrated aqueous NH,CI. They have been assigned structures with C1 cis to the ternary N and with C1 trans to the ternary N respectively.486 The reaction of [Co(NO,),NH,(dien)]Cl with HC1 gives red and violet forms of [CoCl(NO,)(NH,)(dien)]Cl. which both have the mer-configuration. On more prolonged action [CoCl,(NH,)(dien)]Cl is formed. which reacts with en to give fac-[CoCl(en)(dien)]C1,. HBr, however, reacts slightly differently, producing first brick-red mer-[CoBr(NO,)(NH,)dien]Br and. on more prolonged action, green and violet isomers of [CoBr,(NH,)(dien)]Br.HBr.These have mer- and fuc-configurations, respectively, and The reaction of the mer-isomer with en gives ~f~c-[CoBr(en)(dien)]Cl,.~~~ preparations and c.d. spectra of one optical isomer of cis-[Co(en)(NH,),Cl,]+ and a number of isomers of [Co(R-pn)(NH,),Cl,]+ have been reported.488 Diamine complexes. The H n.m.r. spectra of N-deuteriated [Co(en),]’ and [Co(R-pn)J3 in D,O at various temperatures and phosphate ion concentrations have been examined at 251 MHz with 59C0spin-decoupling. It was found that the A(633,) conformation is more abundant than the A(L3A) except at The high PO:- ion concentration, when the reverse situation is structure of [Co(en),],[CdC1,]Cl,,2H,O shows the cation to have the lowenergy A(666) [equivalent to A(hhh)]c o n f ~ r m a t i o n . The ~ ~ ’ absolute configuration of ( + ),,,-[Co(en),(CN),]C1,H20 is A(hh).49’ trans-[Co(en)(NO,),]’ and tr~ns-[Co(en)(NO,),(NN’-Me,en)]~have been prepared and active forms arising from asymmetry at the secondary N atoms were resolved in each case. ‘H n.m.r. studies indicate that only one dl pair was isolated for each complex ion in which the configuration about the asymmetric nitrogen centres is identical. The spectra are consistent with gauche chelate ring conformations, and the active dinitro-complexes could be converted into active dichloro-complexes with the same configurations about the nitrogen centres.492 The related complex trans-[Co(NO,),(NN’-Me,en),]I has also been prepared and resolved.493 The structure of [( -),,,Co(en),(NO,),][( ),,,-Co(en)(malonate),] has been reported. The absolute configurations of both the cation and the anion are A.494 The action of light on trans-[Co(en),(NO,)X]Y (X = NCS, Y = ClO,, NO,, or NCS: X = C1 or NO,, Y = NO,) has been studied.495The action of sunlight on the red complex (X = NCS, Y = C10,) gives a yellow complex

’

+

+

”’ C.-H. L. Yang a n d M . W. Grieb, J.C.S. Chem. Comm.. 1972, 656. 487

488

489

490

49L 492

493

”‘ 495

A. V. Ablov and E. V . Popa. Russ. J. Inorg. Chem., 1971, 16, 1615; 1972, 17, 388. C. J. Hawkins. J. A. Stark. a n d C . L. Wong, Austral. J. Chem., 1972, 2 5 , 273. J. L. Sudmeier. G. L. Blackmer, C . H. Bradley, a n d I;. A. L. Anet, J . Amer. Chem. Snc.. 1972, 94. 757. J. T. Veal and D. J. Hodgson. Inorg. Chem.. 1972, 11, 597.

K . Matsumoto. S. Ooi, and H . Kuroya. Bull. Chem. SOC.Japan, 1971, 44,2721. J. A. Tiethof and D. W . Cooke, Znorg. Chem., 1972, 11, 315, S. Yano, M . Saburi. a n d S. Yoshikawa. Bull. Chem. SOC. Jupan, 1971,44, 3486. K. Matsumoto and H. Kuroya. Bull. Chem. Soc. Japan. 1971.44, 3491. B. Adell. Z . anorg. Clzem.. 1971. 386. 112.


255

with partial isomerization of the nitro ligand to nitrite. The complexes where X = NCS and Y = C10, or NO, give 35 and 47 isomerization, respectively, with light of wavelength greater than 430 nm; however, the other complexes are unaffected by light. The complex cation ( -)-[Co(en),(NCS),]+ can be and L( -)-[Co(en),(CN),] : all three converted into ( -)-[Co(en),(NH,),I3 complexes have the same absolute c ~ n f i g u r a t i o n .[Co(en),(ha)]Cl ~~~ (ha = dianion of lactic or pantolactic acids) are prepared by the reaction of optically active lactic acid with vac-[Co(en),CO,] and optically active pantoyl lactone with trans-[Co(en),CI,]ClO~. Several isomers of both complexes were separated by t.1.c. and their configurations assigned.497 The method of optical dilution has been used to determine the optical purities of partially racemized salicylato-bis(ethy1enediamine) cobalt(rr1) nitratc and oxalato-bis(ethylenediamine)cobalt(m) chloride, and hence to obtain values of Acmaxfor peaks in the c.d. spectra of the pure complex ions.498Rapid reactions involving condensation of co-ordinated ligands to yield terdentate amidine ~]~+ complexes have been studied. Thus, c ~ s - [ C O ( ~ ~ ) , ( N H , C H , C N ) Creacts in neutral or basic solution to yield [Co(en){NH,CH,C(NH,)=C(NH,)CH2NH2)C1I2+where one end of the bidentate en ligand has condensed with 4 s). Features of the bound NH,CH,CN. The reaction is fast at pH 9 (tt crystal structure of the product are: (a) condensation has occurred at the nitrogen trans to C1; (b) the amidine and amino N-C bonds are short and multiple bond character is suggested; (c) the C-N (amidine) bond length is shorter than the remaining C-N bonds; (d) there is a striking distortion of the apical ring. A suggested reaction mechanism is based on deprotonation of the NH, group trans to C1, followed by nucleophilic attack of the co-ordinated amide at the nitrile carbon atom, subsequent proton transfer giving the 'exo'NH, A structural study has been made of ~ - [ C o ( p n ) , ] ~complexes + with regard to the disorder in the cations. It was found that geometrical isomers were indistinguishable, since the cations are disordered giving average D , symmetry, and that the cis-isomer has an ordered structure of C, symmetry, the lattice not having space to accommodate disordered cations or the trans-isomer. The trans-isomer does not crystallize but forms an amorphous glass, and in none of the nine salts examined did it have an ordered arrangement. It was, therefore, impossible to prove directly its existence by X-ray structural analysis.500The temperature-dependent c.d. spectrum of ( +)-[Co(tn),I3 indicates the presence of a conformational equilibrium in solution between tris-skew-boat and trischair forms, the latter being the more stable by 0.5 kcal mol-1.501The structure +

+

-

+

"15 497

498

'''

R. D. Gillard and R. Maskill, J . Chem. SOC.( A ) 1971,2813. E. B. Kipp and R. A. Haines, Znorg. Chem., 1972, 11, 271. R. D. Gillard and J. R. Lyons, J . Chem. Soc. ( A ) , 1971,2817. D. A. Buckingham, B. M. Foxman, A. M. Sargeson, and A. Zanelli, J . Amer. Chem. SOC.,1972, 94, 1008.

500 501

P. F. Crossing and M. R. Snow, J . C . S . Dalton, 1972, 295. P. G. Beddoe, M. J. Harding, S. F. Mason, and B. J. Peart. Chem. Comm., 1971, 1283.

256


of cis-[Co(tn),CO,]ClO, shows that the Co-tn rings are not related by molecular geometry and have different and slightly distorted chair conformations. This isomer is not the one of least strain energy, and although two other strain isomers, one of higher, the other of lower energy are possible, neither were detected in several preparation^."^ [Co(R-pn),(CO,)](ClO,) has been prepared both as a mixture of isomers and as one optically pure isomer. The structures of the isomers were assigned on the basis of c.d. and n.m.r. The ( ),,,-tris(R,R-2,4-diaminopentane)cobalt(111)ion has D, symmetry with the chelating ligands in the twisted boat form,504and ( -)589-tris[( +)-trans1,2-diaminocyclopentane]cobaltchloride tetrahydrate has non-planar chelate rings in the '/el' conformation.505 A study of cis- and trans-[Co(NO,),(E-cy~lohexanediamine)~]Cl shows the trans-isomer to be eluted first from a cellulose ion-exchange column, as a single component, and in fact the cisisomer corresponds to that previously reported as trans. 5 0 6 Tri- and tetra-amine complexes. The structure of s-fac-[Co(diethylenetriamine),]Br, shows each dien ligand to be terdentate with the terminal nitrogen atoms in cis positions.507A comparison of the experimental and calculated equilibrium ratios of the three geometric isomers of [Co(dien)J3 +,suggests that the 'core-field' terms neglected in the strain energy summations are of little imp~rtance.~"Seven solid-state forms of [Co(tmd)(dien)C1]ZnC14 and six solid-state forms of [Co(tmd)(dpt)Cl]ZnCl, (tmd = 1,3-propanediamine, dpt = dipropylenetriamine) have been isolated by various routes: however, only four forms of [Co(tmd)(dien)C1I2 and two forms of [Co(tmd)(dpt)CI]' were distinguishable in aqueous acidic solution. Several bromo-, nitro-, and azido-complexes have been prepared from the chloro-isomers.509The structure [cr-CoCl(en)dpt)]I,,H,O has been reported and the chlorine is trans to an en-nitrogen atom.510 The medium-ring cyclic triamines, 1,4,7-triazacyclononane (tacn), 1,4,7triazacyclodecane (tacd), 1,4,8-triazacycloundecane (tacud), and 1,5,9-triazacyclododecane (tacdd) have been synthesized and the cobalt complexes [Co(tacn),] Br,, [Co(tacd),]Br,,H, 0 and [Co(tacud)BrCl,] isolated. It has been suggested that the structures are of the sandwich type [viz. (95) and (96), ''3 and, for this reason, the reporter looks forward to publication of X-ray structural analyses. The structures of ( - ) 5 8 ,-tratzs and ( - ), 8 ,-cis-or-[Co(N02),(~-3,8-diMetrien)-] C10, (3,g-diMetrien = 3,8-dimethyltriethylenetetramine)have been reported. The Co-N distances of the tetramine are 1.98 A for the trans-isomer and

+

+

502

503

507

509

'lo 511

R. J. Geue and M. R. Snow, J . Chem. SOC.( A ) . 1971,2981. R. A. Haines and A. A. Smith, Canad. J . Chem., 1971,49, 3907. A. Kobayashi. F. Marumo. and Y. Saito, Inorg. Nuclear Chem. Letters, 1971, 7, 777. M. Ito, F. Marumo, and Y. Saito, Acta Cryst., 1971, B27, 2187. B. J. Brennen and B. E. Douglas, J. Coord. Chem., 1971, 1, 297. M. Kobayashi, F. Marumo, and Y. Saito, Acta Cryst., 1972, B28.470. M. Dwyer and G. H . Searle, J.C.S. Chem. Comm., 1972, 726. A. R. Gainsford and D. A. House, Inorg. Chim.Acta, 1972, 6 , 227. D. A. House. P. R. Ireland, I. E. Maxwell, and W. T. Robinson, Inorg. Chim. Acta, 1971,5, 397. H. Koyama and T. Yoshino. Bitfl Chem. Soc Japan. 1972,45.481.


257

1.958 8, (average) for the cis-a-isomer. Potential energy minimization calculations have been carried out for the three isomers and the strain energy was The electronic found to decrease in the sequence cis-a > trans >

spectrum of [Co(3,2,3-tet)C1,]C104 [3,2,3-tet = NH,(CH,),NH(CH,),NH(CH,),NH,] shows a decrease in Co-N interaction compared with [Co(en),C12]f.5l 3 An X-ray structural study of ( +)-[Co(3,2,3-tet)(NOJ2]Br shows the co-ordination to be approximately octahedral with the terdentate ligand occupying the equatorial plane. The absolute configuration is 6 and the configurations of the asymmetric secondary nitrogen atoms are both R.' l 4 A series of optically active linear tetradentate ligands, which have been stereospecifically synthesized, have been used to prepare complexes with a core and both five- and six-membered chelate rings, in an truns-[CoN,Cl,] attempt to correlate the sign of the Cotton effect with the known chiralities of compounds. However, a complete correlation was not p ~ s s i b l e . ~The synthesis, resolution, and properties of some oxalato, malonato, and diacido complexes of Co"' with the stereospecific flexible tetramine ligands 5-Me3,2.3-tet and NN'-bis-(2-picoyl)- 1 -methyl-l,2-diaminoethane (picpn) have been reported. The stereospecificity is demonstrated by comparison of the optical rotation of the ligand prepared via an asymmetric synthesis with that of the ligand isolated from a resolved complex. The stereochemistry of the complexes has been deduced.' Macrocyclic N-donor lignizds and vitamin B analogues. The free amine [(97) tet] can be prepared from the previously reported nickel complex. Cobalt(111) complexes have been prepared with both planar (bcde octahedral) and folded (abcd octahedral) co-ordination. Derivatives of the three ligand configurations arising from restricted inversion at the four chiral co-ordinated secondary amino-groups have been prepared (see Scheme 2) and their stabilities and configurations d i s c ~ s s e d . ~ +

'

512 '13

'L4 '15

'I6 517

S

M. Ito, F. Marumo. and Y Saito, Actu Cryst., 1972, B28, 457, 463. M. D. Alexander, -1. Inorg. Nuclear Chem.. 1972, 34. 387. N. C. Payne, Inorg C h e m , 1972. 11. 1376 L. J. DeHayes, M. Parris, and D. H. Busch, Chem. Comm.. 1971, 1398. J. Cragel and G. R. Brubaker, Inorg. Chem., 1972, 11, 303. N. F. Curtis and G. W. Reader, J . C . S . Dalton, 1972, 1453


258

Na,Co(C0,),,3H20 [Co(r-tet)CO,]

rrans-[Co(P-tet)Cl,]

+

+ (Htet)CIO,,H,O 1

+

= [Co(y-tet)CO,]

+

c

trans-[Co(p-tet)(H2O)J3+

Scheme 2

traits-[Co(cyclam)NO,X]Y complexes (cyclam = 1.4,g.ll-tetra-azacyclotetradecane: X = Br. Y = Br: X = C1, Y = NO,) have been prepared by treating CoBr, in methanol with NaNO, and cyclam to yield trans-[(NO,)Co(cyclam)02Co(cyclam)(N0,)]Rr, and then decomposing this complex with The cobalt(m)-biseither bromine-free HBr or conc. HCI, respectively." thiocyanate complexes of (98) have been reported, and it has been suggested that these are the most faithful structural models of corrins yet prepared.'19 The low-spin Co" complexes (99)react with halogens or halogenocarbon compounds to give the dark-green [Co"'N,X] complexes listed in Table 3 which are all paramagnetic and five-co-ordinate. However, w-hen the sixth co-ordination site is filled (i.e. with pyridine) the complex becomes diamagnetic. The paramagnetism arises from a low symmetry and field anisotropy rather than from unusual ligand field strengths. The complexes show spin triplet-spin singlet equilibria that are temperature dependent. the magnetic moment decreasing with temperat~re.'~~ 518

5L9 "O

C. K. Lui a n d C. K. Poon. J.C.S. Dulroti. 1973. 216. D. St. C . Black and A. J . Hartshorn. J.C.S. C h e n ~Comm.. . 1972. 706. M. Gerloch. B. M. Hipson. and E. D. XlcKenzie, Chrm. Comm., 1971. 1119.


(98) R = +CH2)2-, o-phenylene, or +CHJ-

259

-CH(Me)CH,--,

(99) R = -CH2--, aben; -CHMe * CH,--, abpn ; o-phen, abphen

Table 3 Magnetic moments of[Co"'N,X] complexes520 Complex [Co(aben)Cl] [Co(aben)pyCl]H,O [Co(abpn)Cl] [Co(abpn)Br] [Co(abPn)Il [Co(abphen)Cl]

perf(room temp.)/BM

2.73 diamag. 2.7 3.15 2.78 2.7

The structure of rac-[Co(trenen)N,](NO,),,H,O [trenen = 4-(2-aminoethyl)-1,4,7,lO-tetra-azadecane]has been determined. The complex is octahedral and the quinquedentate ligand forms Co-N bonds of almost identical length [1.95( 6)- 1.964(5) A]. * A new series of vitamin B,, model compounds has been prepared by treating the cobalt(r1) chelate (100) with BH, in the presence of RX (R = Me, Et, Pr", Bun, n-pentyl, n-hexyl, n-heptyl, n-octyl, or n-decyl). All the complexes RCoL have pseudo-octahedral structures in the solid state and, in poorly 521

I. E. Maxwell, Znorg. Chem., 1971, 10, 1782.

260


co-ordinating solvents, an equilibrium between five- and six-co-ordinate species is set up.'22 Cyanation and nitration of cobalt(I1) tetradehydrocorrin salts yield cobalt(r1r)derivatives which are easily converted into neutral cobalt(1) complexes. These can in turn be reversibly oxidized to stable cobalt@) comof cobalt(I1)-meso-tetra-p-tolylporphinwith cyanogen p l e x e ~ The . ~ ~reaction ~

~ of bromide in CHC1,-MeOH yields the complex [ C ~ " ' ( p o r ) B r ] .A~ ~series other reactions of these two complexes has been reported and these are shown in Scheme 3. The role of methylene blue as an inhibitor of the reduction of hydroxycobalamins by C O has been studied.',' Oxirnato-complexes. When [Co(MH),(amine),]Cl,xH,O (MH = methylglyoxime, amine = NH,, py, o-toluidene, or p-anisidine) complexes are treated with alkali, one proton is removed from an MH ligand.'26 cis-[Co(dmgH)(dmgH2)en]X,,2H,O (X = C1 or Br) and [Co(dmgH),en]ClO,,~H,O have been reported. This is the first report of cis-complexes of this type, although many trans-complexes are known.527 Oxidation of Co(N0,),,6H20 in the presence of dmg and p-NH,C,H,S02NHR (Sam) yields [Co(dmg)(Sam),]NO,,nH,O (n = Ckll). The thermal stability of these complexes is high and i.r. evidence suggests the Sam ligands are co-ordinated via the amino-group bonded to the benzene ring.528When KOH is added to a solution of trans[Co(dmg),I(H,O)], a proton is removed from the water molecule.529The complexes Na[Co(dmg)(SO,)X] (X = urea, thiourea, selenourea, acetamide. dimethylacetamide semicarbazide, thioacetamide, thiosemicarbazide, thioacetanilide, or diphenylthiourea) have been isolated. The co-ordinated SO: group is not displaced by excess X, but treatment with SO:- ions gives [C~(drng),(SO,),]~-. Treatment with water gives rapid displacement of X (0-donor ligand) but only slow displacement when X is an S- or S e - d ~ n o r . ~ ~ ' 521

s23 524

52s

526

'17 s28

s29 s30

W. M . Coleman and L. T . Taylor. J . Amer. Chem. SOC.,1971, 93. 5446. C. M. Elson. A. Hamilton. A. W . Johnson. and C. Stubbs. J.C.S. Chem. C o m m . , 1972,453. N . Datta-Gupta. J . Inorg. Nuclear Chem.. 1971. 33. 4219. G. N. Shrauzer and W. J . Mlchaely. L. iVaturforsch.. 1972. 27b, 571. G. P. Syrtsova. Russ. J . Inorg. Chem.. 1972. 17, 91. N. Maki, Bull. Chem. SOC.J a p a n . 1971. 44, 2283. V . N . Shafranskii and I . L. Fusu. Russ. J . Inorg. Chem.. 1971, 16. 1171. B. A. Bovykin. Russ. J . Inorg. Chem.. 1972, 17, 89. G. P. Syrtsova and N. N. Cheban, Russ.J . Inorg. Chem.. 1971, 16, 1318.


26 1

W'

'

A

v

Kf

Br

(with ring bromination)

I

CN N,I

N

/coy

N

N'

Scheme 3

N- and S-bonded isomers of [Co(dmg),(4-But-py)(thiocyanate)] undergo Co"catalysed equilibration in D M F or DMSO to approximately equal amounts.53 This is similar to the results obtained by Norbury et al. for [Co(dmg),(CNS)py] (see Vol. 1, p. 18i). [Co(dmg),X(H,O)] reacts with PPh, in hot methanol or ethanol to yield two crystalline, modifications of [Co(dmg),X(PPh,)] (X = C1, Br, or I). Preliminary X-ray studies indicate that the two modifications belong to different space groups and they may be geometrical isomers.532trans-[Co(dmg),531

532

L. A. Epps and L. G . Marzilli, Chem. Comm., 1971, 109. A. V. Ablov, A. M. Gol'dman, 0. A. Bologa, Y . A. Simonov, and M. M. Botoshanskii, Russ. J . Inorg. Chem., 1971. 16, 1167.

262


(H,O),]NO,,H,O reacts with CN-cyclohexyl to yield [Co(dmg),)(CN-cyclohexyl),]NO,. The corresponding C1-, I - , NCS-, and ClO, salts have also been ~ r e p a r e d3.3~In the co-ordinating solvents py, PhNH,, or 3,5-lutidine (L), (Ph21)[Co(dmg),(CN),] forms [Co(dmg),(CN)L] and an autophenylation mechanism is suggested for the reaction, whereby nucleophilic attack takes place on the anion yielding PhI and the intermediate [Co(CN)(CNPh)(dmg),], the CNPh ligand then being displaced by L.534 Pyridine-cobaloxime reacts with indene and indene oxide to yield 1-indenyl- and 2-hydroxy-1 -indenylcomplexes, respectively. These undergo oxygen insertion into the C o - C bond to give peroxo-compounds.535 Temperature-dependent n.m.r. studies have been made on [RCo(dmg),], (R = Me. CH,Cl, or CHF,),"' and the reaction of [MeCo(dmg),], with bases, L, gives [MeCddmg),L]. Complexation is Ph,P, DMSO, and essentially complete for L = Me,N, MeCN, py, ,:YI~O),P, Me,S. but incomplete when L = Ph2S0.537Irradiation of [RCo(dmg),py] in the presence of S, yields [RS,Co(dmg),py] [R = Et, Pr, n-pentyl, Ph, o-HO.C,H,. PhCH,, Me(Ph)CH. or CH, *CH=CHMe].538 Oxidation of Co(OAc), in the presence of diaminoglyoxime (aglH,) and bases L gives the cations [Co(aglH),L,]+ (L = PhNH,, py, or y-picoline) which have been isolated with a variety of anions.s39 In general, unsubstituted alkylcobaloximes (e.g.R = Me) are unreactive towards base, but the halogenoderivatives have been found to readily undergo a reaction to form ROH with Co--C bond cleavage and formation of Co'. The compounds [RCoL,py] [R = CH,X,, CH,X, CX, (X = C1, Br, or I), CF,, CH,OMe, or CO,Me, L = acetyldioximate] were studied, and reaction with NaOMe in MeOH gives the corresponding methyl ethers.540The 0-and n-electronic effects in [RCo(DO(DOH)pn}X] (R = rn- and p-FC,H,-, DO(D0H)pn = diacetylmonoximeimino-diacetylmonoximatoiminopropane) have been estimated by "F n.m.r. It has been suggested that the o-bonding effects are similar to those observed for Pt" and that there is extensive n-interaction with aryl ligands co-ordinated to both Co"' and Pt", which is modified by the trans ligand X. However, this modification of n-interaction by X is different for the two metals.541 Aerial oxidation of Co(OAc), in the presence of the a-dioximes, (mdimethylglyoxime, 1,2-cyclohexanedioxime, or 1,2-~yclopentaneglyoxime dioxH,) and KCN gives H [ C O ( Y - ~ ~ O ~ H ) , ( C N The ),].~ systhesis ~' and structure of the bridged cobaloxime (101) have been reported.543 533 533 535

536 537

538 539

54'

5J2 543

A. V. Ablov. D. G. Batyr. a n d M. P. Starysh, Russ. J. Znorg. Chem., 1972, 17, 145. N. B. Egen a n d R. A. Krause, Inorg. Chem., 1972, 11, 1327. C. Giannotti, C . Fontaine, a n d A. Gaudemer, J. Organometallic Chem., 1972, 39, 381. A. W. Herlinger a n d T. L. Brown, J . Amer. Chem. SOC.,1972,94, 388. T. L. Brown, L. M. Ludwick, a n d R. S. Stewart, J . Amer. Chem. Soc., 1972,94, 384. C. Giannotti, C . Fontaine. B. Septe, a n d D. Doue, J . Organornetallic Chem.. 1972, 39, C74. C. Varhelyi, F. Karczynski, a n d F. Manok, Rociniki Chem., 1971, 45, 1399. G. N . Schrauzer. A. RJbeiro. L. P. Lee, and R. K . Y . Ho. Angew. Chem. Znternat. Edn., 1971, 10. 807. H. A. 0. Hill. K. G. Morallee, F. Cornivez, and G . Pellizer, J . Amer. Chem. Soc., 1972, 94, 277. C. Varhelyi. I. Ganescu, a n d L. Szotyori, Z . anorg. Chem., 1971, 386, 232. M . W. Bartlett and J. D. Dunitz, Helv. Chim. Acta, 1971. 54. 2753.


263

The Schiff base, HON=CMeCMe=N(CH,),NH(CH,),NH(CH,)," CMeCMe=NOH (L) reacts with Co" salts to give [CoLIX (X = Br, I, or C10,). Reaction of this complex with HBr or HClO, gives [Co(H,L)]Br3,3H,0 and [Co(H,L)](ClO,),, re~pectively.'~~ Other N-Donor ligands. The structure of [Co(NH,Me),Cl](NO,), has been reported and, somewhat surprisingly, steric interactions cause large deformations in the Co-N-C, N-Co-N, and N-Co-C1 bond angles.',' The structure of [Co(bipy),NO3](NO3)(OH),4H,O shows the nitrate group to be bidentate, giving rise to octahedral ~ o - o r d i n a t i o n . ~Chromatographic ~, resolution on cellulose of [Co(phen),Cl,]+ has enabled a cis configuration to be assigned: X-ray and spectral studies support this.547A series of complex ions [ C O " ' ( C , H ~ N ~ ) ~ X(C,H,N, ~]"~ = 2-picolylamine; X = Cl, NO,, H,O, or NH,) have been prepared. Two types of complex were observed, one containing completely unsymmetrical complex ions and the other having complex ions with a two-fold axis of symmetry. No complexes containing unidentate C,H,N, were observed.548The Schiff base formed from pyridine-2-carboxaldehyde and l,l,l-tris(aminoethyl)ethane, py3tame (102), forms an octahedral Co"' complex.' 'O

The bis(biuretato)cobalt(III) complex K[Co(3-propbi),],2( 1-propbiH,) (3propbi = NH CO . NPr" CONH, -, 1-propbiH, = Pr"NH * CO NH CO NHPr") is paramagnetic (p = 3.51 BM between 120 and 300 K, p = 3.41 BM in DMSO at room temperature). An X-ray structural study shows the anion to have planar co-ordination uia the deprotonated amide nitrogen atoms of the

-

544 545 546 547 548

A. V. Ablov, N. I . Belichuk,and V. N. Kaftanat, Russ. J . Inorg. Chem., 1972, 17, 392. B. M . Foxmann, J.C.S. Chem. Comm., 1972, 515. C. W. Reimann, M. Zocchi, A. D. Mighel1,and A. Santoro, Acta Cryst., 1971, B27,2211 J. A. Broomhead and W. Grumley, Inorg. Chem., 1971, 10,2002. K. Michelson, Acta Chem. Scand., 1972,26,769.

264


chelating dianions (Co-N = 1.88 A). The electronic spectrum is in accord with a low-lying spin triplet state and reactions with amines give octahedral L, J ions.'" The complex K[Co(biuretato),] reacts with [C0(3-propbi)~ dithiocarbamates to give [Co(bi),(S,CNR,)]' - and [Co(bi)(S,CNR,)]- at O'C (1: 1 mole ratio) and room temperature (1:2 mole ratio), respectively.550 O-DOl70r lignnds. A re-investigation of the thermal decomposition of M,[Co(NO,),] ( M = Na or K)"' shows the reaction to proceed via: 2M,[Co(NO,),]

.+

MNO,

+ 5 M N 0 , + 2CoO + 3 N 0 + 3N0,

The nature of the [Co(CO3),I3- ion in aqueous solution has been studied by ] Co(OAc), is 1.r.and by optical resolution achieved by means of( + ) - [ C ~ ( e n ) ~+. conveniently synthesized by ozonation of Co(OAc), in glacial acetic acid. The triacetate has the empirical formula [Co,( OAc),(OH),(HOAc)] and exists largely as the p-hydroxy-dimer in glacial acetic The action of bromine on potassium tris-malonatocobalt(i1I) leads only to decomposition: however. with N-bromosuccinimide in CCI,, K,[Co(bromomalonate),] is formed.554 The structure of [Co(amidoxalato),(H,0)2]2H,0 shows it to have a trans-octahedral structure, the amido-oxalate ligands chelating cia one carboxylate oxygen and the amidic oxygen.555 or [Co(acac),] on to Adsorption of tris-( l-phenyl-1,3-butanediono)-cobalt(111) a D( + )-sorbit01 or D( + )-mannit01 column. followed by elution with benzeneligroin effects a partial resolution into optically active fractions.556 The complexes [Co(en),dik), (dik = acac. hexane-2,4-dione. l-trifluoromethylbutane1.4-dione. 1 -carboxyet hylpropan-2-one. or 1-carboxyethylacetophenone) have been prepared. Absorption. 0.r.d.. and c.d. spectra indicate that ( +)-[Co(en),c i s - and trans-[Co(acac),(NO,)dik]'- has the absolute configuration (amine)] (amine = NH,. MeNH,. Me,NH. Me,N. PhNH,, or piperidine) have been isolated and their stereochemistry assigned by ' H n.m.r. In CHCI, solution, all the trans-complexes isomerize at a rate depending on the amine, the aniline complex being much faster than the others. This complex also shows slow coniersion in the solid state. The preparative routes employed are outlined below:5 i8 +

,

t runs-[Co(acac), (NO,),] - + H 0 trans-[Co(acac),( N 0,)H trans-[Co(acac),(NO,)H,O] + L = rrans-[Co(acac),(NO,)L] truns-[Co(acac),(NO,)L] = cis-[Co(acac),(NO,)L] 549

541

552 553

554 555 556 557

,01 + N 0; + H,O

J. J . Bour, P. T. Beurskens, and J. J. Steggarda. J.C.S. Chem. Comm., 1972. 921. H. Brinkoff, Inorg. Nuclear Chem. Letters, 1971.7. 413. M. B. Davies and J. W. Lethbridge, J . Inorg. Nuclear Chem., 1972, 34, 2171. R.D. Giilard, P. R. Mitchell, and M. G . Price. J.C.S. Dalton. 1972, 1211. S. Lande, C . D. Falk, and J. K. Kochi. J . Inorg. Nuclear Chem., 1971. 33,4101. M. S. Al-Obadie, J . Inorg. Nuclear Chem.. 1972, 34, 2378. M. Pellinghelli, A. Tiripicchio, and M. Tiripicchio-Camellini, Acta Cryst., 1972, B28,998 V . G . Markovic and G. K. Schweitzer. J . Inorg. Nuclear Chem.. 1971, 33. 3197. L. J. Boucher, Inorg. Chim. Acta, 1972. 6 . 29. L. J. Boucher and N. G . Paez. Inorg. Chmi.. 1971, 10. 1680.


265

The reactivities of [M(acac),] complexes (M = Co or Cr) have been compared by a study of nitration and Vilsmeier-Haack formylation reactions. It was found that the cobalt complex is more reactive than its chromium analogue.559 An n.m.r. study of (103a) shows the presence of both cis- and trans-isomers at below -20°C. Line-shape changes at high temperatures show the molecule to be stereochemically non-rigid on the n.m.r. time-scale and activation parameters for cis-trans isomerization have been obtained. It is suggested that the 'trigonal-twist' mechanism is the most likely pathway for isomerization; (103b) is also stereochemically non-rigid and the results for these complexes reveal that cobalt(rI1) tropolonates invert ca. 10" times faster than the corresponding P-diketonates. 6o

R (103) a; R b; R

= a-isopropenyl = a-isopropyl

S-Donor figands. [Co(sacsac),] has been prepared by treating [Co(sacsac),], in HCl-EtOH containing acac and H,S, with a stream of oxygen at 0°C for 36 h, followed by treatment with H,S at 50°C for 12 h.561The structure of ( +)5,,-KCa[Co(l,2-dithioxolate)3],4H,0 shows the anion to have D , symmetry, there being a small distortion towards trigonal-prismatic co-ordination. The absolute configuration is A.562 The structure of tris-ethylthioxanthatocobalt(II1) has been reported.563The complexes [Co(S,CSR),] (R = Me, Et, Pr", But, or PhCH,) and [Co(S,CSR),(SR)], (R = Et or Pr") have been reported. The elimination of CS, from the tris-complexes to give the dimers has been directly confirmed and the reactions found to be first order. The structure of the ethyl dimer has been reported and it is found to be centrosymmetric with bridging SEt groups. Relevant dimensions are C o - . - C o= 3.321 A, Co-S (chelating) = 2.261, 2.264, 2.282, and 2.290 A, L S-Co-S(bridge) = 84" and 95", L S-Co-S (chelating) = 76". The 'H n.m.r. spectrum of the dimer is consistent with the solid-state structure being maintained in The structure of Co[S,P(OMe),], has been reported565and the analogous compound Co[Se,P(OEt),], has been prepared. The latter has a magnetic moment of 1.98 BM (298 K) and 1.77 BM (131.5 K) 559

560 561 562

563 564

T. Schirado, E. Gennari, R. Merello, A. Decinti, and S. Bunel, J . Inorg. Nuclear Chem., 1971,33, 3417 S. S. Eaton and R. H. Holm, J . Amer. Chem. Soc., 1971, 93,4913. G. A. Heath and R. L. Martin, Austral. J. Chem., 1971, 24, 2061. K. R. Butler and M. R. Snow, Inorg. Nuclear Chem. Letters, 1972, 8, 541. A. C. Villa, A. G. Manfredotti, C. Guastini, and M. Nardelli, Acta Cryst., 1972, B28, 2231. D. F. Lewis, S. J. Lippard, and J. A. Zubieta, J . Amer. Chem. Soc., 1972. 94, 1563.


266

and it is suggested that these values are too high to be due to impurity effects of cobalt(r1)in the cobalt(rr1)complex.566 The dit hiolato-complexes [CoL(S-S),] - [S-S = S,C,(CN),, S2C2(CFJ2, or S,C,Cl,: L = o-C,H,(AsMe,),. Ph,As(CH,),AsMe,, cis-Ph,PCH=CHPPh,. Me,PhP, or Me,PhAs], [CoL(S-S),] [S-S = S,C,Ph2: L = Ph,As{ S,C,(CN),}] have (CH,),AsPh, or Me,PhAs], and [CO(O-C,H,(ASM~,)~) - (qdt = 2,3-quinbeen r e p ~ r t e dl C. ~) The octahedral complex [C~"'(qdt),]~ oxalinedit hiol) has been prepared.567 Amino-acid cornpleses. truns-(0,X)-[CoX(aminoacidato)(dien)]Y (X = CN, NO,, or C1: Y = Br, C1, or (210,; aminoacid = Gly, a-aminobutyric acid, L-Ala. L-Val, L-Thr, or L-Pro) complexes have been isolated. The cyanocomplexes were shown to exist in the new conformational isomeric endo- and em-forms. This refers to the position of the hydrogen atom bonded to the The tetramine ligands central N of dien with respect to the cyanide 1,3-diaminopropane, 3,7-diaza- 1,9-nonanediamine (2,3,2-tet), and 4,7-diaza1.1 0-decanediamine (2.2,3-tet) exhibit marked topological specificity in the complexes [Co(tetrarnine)(aa)]'-. (aa = Gly. Ala. Val. or Sar). Thus a- [Co(3,2,3-tet)aaI2 and P2-[Co(2,3,2-tet)aa]' * appear to be formed exclusively under the synthetic conditions e r n p l ~ y c d . ' ~ ~ The configurations of the A 4 - ) 5 R 9 - P , - ( R R ) -A-( , - )s89-P,-(RS)-: and p2( R R . S S ) - [ C ~ ( t r i e n ) g l y ] ~cations + have been determined by X-ray methods. The p, - [Co(trien)gly]I,,O.SH,O complex contains one RR- and one RS-cation per unit cell and the p, cation was studied as its dichloride monohydrate. These structures together with mutarotation and equilibrium studies allow all the P I . p,. and x configurations to be assigned. Eight of the ten possible isomers of this system (ARR. ,4SS, ARS.and .4SR for PI and p,) were isolated and characterized. The other two, ASS and ARR form, were also prepared and found was to be optically stable in alkaline solution.570 1,2,4-Triglycinatocobalt(111) initially resolved by stereoselective decomposition with the bacterium proteus culgnris and finally resolved by fractional recrystallization from water to give a 99.8 & 1.5 ",; optically pure compound.571The reaction of [Co(Gly),CO,]with (S)-(+)-Glu gives [Co(Gly),], Co(Gly),(Glu)]-. [Co(Gly)(Glu),]-, and [Co(Glu),] - as the water-soluble Three isomers of Na[Co"'(~-apa),] have been prepared as a mixture from Co(OH), and apaH (apaH = L-aspartic acid) in the presence of NaOH. The brick-red. violet. and blue-violet optical isomers were separated by chromatography, the first having trans-N. the second cis-N-trans-0,, the third ci.\-N+

565 566 56'

J. F. McConnell and A. Schwartz, Acra Crysf., 1972, B28, 1546. V . Krishnan and R . Zingara. J . Coord. Chem.. 1971, 1, 1. K. F. Ganguli, G. 0. Carlisle, H. J. Hu. L. J. Theriot, and I. Bernal, J . Inorg. Nuclear Chem., 1971, 33, 3579.

568

569 5'o

'" 512

K . Ohkawa. J. Fujita. and Y . Shimura. Bull. Chem. SOC. Japan, 1972,45, 161. G. R. Brubaker and D. P. Schaefer, Inorg. Chem.. 1971, 10, 2170. R. J . Dellaca, V. Janson, W. T. Robinson, D. A. Buckingham, L. G. Marzilli, I. E. Maxwell, K. R. Turnbull, and A. M. Sargeson, J . C . S . Chem. Comm., 1972, 57. R. D. Gillard, J. R. Lyons, and C . Thorpe, J . C . S . Dalron, 1972, 1584. F. Jursik and B. Hajek, Coll. Czech. Chem. Comm.. 1971,36, 3362.


267

trans-0,. The assignments were made by means of n.m.r. studies57 3 * 74 Isomers of the complexes [Co(en),(~-aa)]+ (aa = Asp or Glu), [Co(en),(~-Haa)]~+, and the model compound [Co(NH3),(~-Asp)] have been isolated and characterized. The diastereoisomers of each complex were separated by chromatography and, in each complex, the amino-acid was found to co-ordinate via the five-membered glycinate ring, as demonstrated by selective deuterium exchange of the methine proton. These results suggest that it may be possible to use a tetramine-cobalt(rr1) complex to hydrolyse peptides N-terminal in these amino-acids selectively, as it is not anticipated that co-ordination through the larger six- (Asp) or seven-membered (Glu) ring will take trans[CoCl,(I-pn),] reacts with L-aspartic acid to give [Co(l-pn),(~-apa)] and [Co(l-pn),(~-Hapa),]+. Stereoisomers of these complexes were separated by ion-exchange. Eight possible isomers of the former were separated and four A isomers and one A isomer isolated. A- and A-trans-(0)-, A-, and A-cis-(0)cis-")-, and A-trans-(N)-isomers of the latter were i ~ o l a t e d76. ~ X-Ray studies on Na[( -),,,-Co(ox)(aa),],2H20 [aa = trans-N-methyl(S)-alaninate] confirm the RS configuration of the aa ligands and show the Fractional crystallization and absolute configuration of the anion to be L4.577 column chromatography on D-lactose has been used to separate diastereoisomers of [Co(acac),(~-Phe)] and [Co(acac),(~-Val)]. The method was, however, unsuccessful for the corresponding L-Ala c ~ m p l e x7 .8 ~ Protonation of [Co(Gly-Gly),] in aqueous acidic solution occurs at the peptide 0 rather than at the co-ordinated deprotonated peptide N atom as had been previously proposed. The two peptide linkages are protonated in a stepwise fashion., 7 9 Peptide formation using the three-site moiety [Co(dien)I3 has been illustrated by the reaction of [Co(dien)Cl,] with glycine esters and Gly-Gly esters to give [Co(dien)(Gly-Gly-OR)XI2+ (X = C1 or NO,) and [Co(dien)(Gly-Gly-G1y-Gly-OEt)12 , respectively. The related complexes [Co(dien)(Gly-O)X] +,[Co(dien)(Gly-NHR)X]'+ (R = H or Me), [Co(dien)(Gly-Gly-OH)X]' , and [Co(dien)(Gly-Gly-0)] have also been prepared. An interesting complication was found in the formation of the tetrapeptide complex. At low pH, bidentate chelated dipeptides bond to Co"' via the terminal amines and the 0 atoms of the adjacent carboxamide functions. In such a configuration, the 0 atom of the second amino-acid residue cannot reach the metal to produce terdentate chelation and activate the second carboxyl function. In order to form the peptide linkage, the first dipeptide must isomerize from Co-0 to Co-N bonding.580 Reaction of Co", oxygen, and G ~ Y - L histidine, followed by ion-exchange and Sephadex chromatography, gives five +

+

+

+

+

+

+

S. Yamada, J . Hikada, and B. E. Douglas, Inorg. Chem., 1971, 10, 2187. L. R. Froebe, S. Yamada, J. Hidaka, and B. E. Douglas, J . Coord. Chem., 1971,1, 183. 5 7 5 J. I. Legg and J. Steele, Inorg. Chem., 1971, 10,2177. 5 7 6 Y. Kojima and M . Shibata, Znorg. Chem., 1971, 10, 2382. "' G. W. Svetich, A. A. Voge, J. S. Brushmiller, and E. A. Berends, J.C.S. Chem. Comm., 1972,701. S. H. Laurie, J.C.S. Dalton, 1972, 573. 5 7 9 D. L. Rabenstein, Canad. J . Chem., 1971,49,3767. 5 8 0 Y. Wu and D. H. Busch, J . Amer. Chem. SOC.,1972,94,4115.

573

574

268

Inorganic Chemistry of the Transit ion Elements

Co"'-(Gly-~-His)complexes. three of which are mononuclear. the other two being dinuclear. All five have Co: peptide ratios of 1 : 2 and the manner of the ligand to metal bonding has been elucidated by n.m.r. and titration c u r t e ~ . ~ ~ ' Schiff-base ligands. The structures of [Co(salen)(P-dik)],nH,O (P-dik = acac, n = 0.7: P-dik = benzoylacac. n = 1.5) have been reported. Both show bidentate co-ordination of the P-diketonate and a strained non-planar conformation of the quadridentate ligand.58' A range of compounds of the type [Co(salen)(fbdik)] have been prepared by the reaction of [Co(salen)X] (X = halogen or alkyl) with the respective P-diketone or its sodium or thallium salt. Spectral studies of the products indicate oxygen chelation rather than C O X bond formation by the b-diketonate and that the salen ligand adopts the twist configuration."' The structure of [EtCo(salen)] shows it to be a centrosymmetric dimer achieved by co-ordination of one cobalt atom by an oxygen atom of the other [EtCo(salen)] moiety.584 The structures [(vinyl)Co(salen)py] and [MeCo(acacen)py] have been reported, both Schiff bases occupying the four equatorial - [(do)(doh)pn = monopositions. 8 5 The complexes [PhCo'((do)(doh)pn>] anion of l-diacetylmonoximatoimino-3-diacetylmonoximinopropane) and [PhCo'(chel)(DMF)]- (chel = salen, 7,7'-Me,salen, or acacen) have been and obtained by electrochemical reduction of [PhC~"'{(do)(doh)pn)H~O]~~ [RCo(chel)H,O] respectively. These Co'-Ph derivatives were stable for several hours in solution under nitrogen and evidence was obtained for the unstable Me- and Et-Co' complexes.586 The reaction of [Co(chel)] with PR, in methanol-ether at room temperature. followed by the addition of an aqueous ClO, solution gives either [Co(chel)PR,]CIO, or [Co(chel)(PR,)H,O]C10, (chel = salen. 7,7'-Me,salen. saloph, or acacen). In non-complexing solvents both types of complex are thought to have square-pyramidal coordination, and the thermodynamic trans-effect of PR, is indicated by the stoicheiometric formation constants of [Co(chel)(PR,)(NO,)], which can be correlated with the o* Taft constants of the phosphines. The trend of transeffect of L in [Co(chel)L(H,O)]+ is PR, > organic group > OH- > H , 0 . 5 8 7 Reaction of TCNQ (104) with rCo(acacen)] in pyridine gives low-spin [Co(acacen ) ( P ~ ) ~ ] . T C Nand Q . e.s.r. measurements have shown this to contain Co"' ,tnd (TCNQ)- not Co'' and TCNQ. Thus the complex 4hould be foimulated as [Co(acacen)(py),] +(TCNQ)-. The 2: 1 complex [Co(acacen)(py),],.TCNQ has also been isolated and is formulated as [Co"'(acacen)(py),]~-

583 584

'" '*'

R. D. Gillard and A. Spencer, J.C.S. Dalton, 1972,902. N. A. Bailey, B. M. Higson and E. D. McKenzie, J.C.S. Dalton, 1972. 503; M. Calligaris, G. Manzini, G . Nardin, and L. Randaccio, ibid, 1972, 543. R. J. Cozens and K. S . Murray, Austral. J. Chem.. 1972, 25,911. M. Calligaris. D. Minchelli, G. Nardin. and L. Randaccio, J . Chem. SOC.(A), 1971, 2720. M. Calligaris. G . Nardin, and L. Randaccio, Itiorg. Nuclear Chem. Lerrt,t +.1972, 8, 477; J . C . S . Dalton 1972, 1433. G. Costa, A. Puxeddu, and E. Reisenhofer, Chem. Comm., 1971, 993. G. Tauzher. G . Mestroni, A. Puxeddu, R. Constanzo, and G . Costa. J . Chem. Soc. (A), 1971, 2504.


269

(TCNQ)2-.588 t r a n s - [ C o X ( H D f ) , ( H , O ) ] ( X = C1, Br, or I ; H D f = benzildioximate) and trans-Na[Co(NO,),(HDf),] react with Ph,E (E = P or Sb) to give [CoX(HDf),(EPh,)] (X = C1, Br, I, or NO,).589Polarographic techniques have been used to investigate the electrode processes and the effect of both axial and equatorial ligands on the half-wave potentials of Co"' -+ Co" -+ Co' for a series of cobalt-Schiff-base organometallic compounds.590

(104)

Other mixed donor ligands. The preparation of Cs[Co(edda)X,] (edda = ethylenediamine-NN'-diacetate, X = NO, or N,; X, = ox) complexes has been r e p ~ r t e d . ~Four " cobalt(m) complexes containing N-alkylated edda have been completely resolved and their c.d. spectra have about half the intensity of the unsubstituted compounds. This is attributed to a lower contribution to the asymmetry of the complexes from the nitrogen atoms of the N-alkylated ligands compared to the unsubstituted l i g a n d ~ . ~On ~ ,heating K[Co(trdta)],2H,O, a cobalt(r1) complex is formed, which can be oxidized by peroxide and air in water to form violet K[Co(trdta)(H20)],2H2O. This was purified by ion-exchange and i.r. evidence indicates that all three carboxylate groups are An n.m.r. study of co-ordinated. (trdta = trimethylenediaminetria~etate).~~~ [CoYX] (X = NO; or H , O , Y = edta, ethylenediaminetriacetate, N-methylethylenediaminetriacetate, N-hydroxyethylenediaminetriacetate,or 1,2-diamino-2-methylpropanetriacetate)indicates the presence of only one geometrical isomer, with X occupying an equatorial site.594This is contrary to the reports of other workers. who favour out-of-plane substitution. The structure of K[( - ),4,-Co(trimethylenediaminetetra-acetate)],2H20 shows the ligand to be sexidentate with cis-N atoms and the absolute configuration to be AAA.595 Optically active 2,4-pentanediaminetetra-acetate ( R R or S S ) forms a sexidentate complex, the absolute configuration around the metal atom being meso-ligand (RS). Such stereospecific complex formation has been attributed to steric regulation coming from the methyl groups on the a-carbon atoms.596Yellow and violet geometric isomers of both tris-N-(2-hydroxyethyl)ethylenediaminecobalt(ir1) and tris-N-(2-hydroxypropyl)ethylenediamineco588 589

590

591 592

593 594

595 596

S. G. Clarkson, B. C. Lane, and F. Basolo, Inorg. Chem., 1972, 11,662. A. V. Ablov, A. M. Gol'dman, and 0. A. Bologa, Russ. J . Znorg. Chem., 1971, 16, 937. G. Costa, A. Puxeddu, and E. Reisenhofer, J.C.S. Dalton, 1972, 1519. K. Kuroda and K. Watanabe, Bull. Chem. SOC.Japan, 1971,44, 2550. C. W. Maricondi and B. E. Douglas, Znorg. Chem., 1972, 11,688. N. Tanaka, K. Sato, and H. Ogina, Inorg. Nuclear Chem. Letters. 1972,8, 93. G. L. Blackmer and J. L. Sudmeier, Znorg. Chem., 1971, 10, 2019. R. Nagao, F. Marumo, and Y . Saito, Acta Cryst., 1972, B28, 1852. F. Mizakami, H. Ito, J. Fujito, and K . Saito, Bull. Chem. SOC.Japan, 1971, 44, 3051.

270


balt(iii) have been prepared. The yellow isomers have a 1,2,3-configuration and the violet forms are 1,2,6.597 Thiosemicarbazides, Rthiosh (R = Ph, MeC,H,, CH,=CHC,H,, or ClC,H,) form the complexes [Co(dmg),(Rthiosh),]Cl~, [CoCl,(dmg),(Rthiosh)],and [ C o ( R t h i ~ s h ) , ] C l , .The ~ ~ ~ligand (105) forms the complex Na[CoL(OH),],H,O at pH 12.5.''' The dithiocarbazate complexes Co(S,CNR3NR'R'), (R' = R 2 = R3 = H ; R' = R 2 = H, R3 = Me; R' = Me, R2 = H,

ooH

CO-NH-NH-CS*NH*NEI,

R3 = Me; R ' = R' = Me, R3 = H: R ' = R' = Ph, R 3 = H ) have been isolated.'99 The ligand (106) forms the complexes [Co(dmg),L],1.5H2O and [ C O ( ~ ~ ~ ) , L , ] C ~ , ~The H , complex O . ~ ~ ~ [Co(mdtc),] (mdtc = morphiline-4carbodithiozate) has also been reported.328

UH \

CH=N-NH.CSe.NH,

Polvntrclear anion-bridged complexes. The structure of [(NH,),(H,O)Co( ~ - O H ) , C O ( H ~ O } ( N H ~ ) ~ ] ( ~ Ohas ~ ) ~been , ~ Hreported, ,O although it was not possible to distinguish between the ammine and aquo ligands."' When [Co(acac),] in methanol, containing KOAc, is treated with H,O at 25°C is formed.602 The structure of racfor 1 h, [(a~ac)~Co(~-OH),Co(acac)~]

(en),

(107) 591

59B 599 600 601

602

E. I . Karpeiskaya, Y. N . Kukushkin, V. A. Tromfimov, and I . P. Yakovlev, Russ.J. Inorg. Chem., 1971,16, 10'42. B. A. Bovykin and N. A. Barba, Russ. J. Inorg. Chem., 1971, 16, 1032. C. Battistoni, G. Mattogna, A. Monaci, and F. Tarli, Inorg. Nuclear Chem. Letters, 1971,7, 1081. A. V. Ablov, N . V . Gerbeleu, and M. V. Shopron, Russ. J . Inorg. Chem.. 1972. 17, 384. K . Wieghardt, Z. Naturforsch., 1971, 26b, 987. L. J . Boucher and D. R . Herrington, J. Inorg. Nuclear Chem., 1971,33,4349.


27 1

[Co(Co(OH),(en),),](dithionate),,8H20 shows the cation to have structure (107)and thecationantipodesexhibit the configurations A(AAA) andA( L I A A ) . ~ ' ~ The reaction of [Bu,PCo(salen)]' and OH-, followed by the addition of ClO,, gives [Bu3PCo(salen)(p-OH)Co(salen)PBu,]C104.~04 The structures of the related compounds [(NH3),Co( ~-OH)(~-NH,)CO(NH,),](SO~)~,~H and [(en), Co(p-OH)(p-NH,)Co(en),](NO q)4.H 0 have been determined.' as have those of [(NH3 ) 3 Co(p - 0 H)(p-SO,),Co( NH ,),I ,SO,, 8H 0 and [(en),Co(p-NH,)(p-SO,)Co(en),] Br, .6 O6 When [(NH,)4Co(p-NH,)(p-Cl)Co(NH3)4]4+ is treated with oxalic acid in water at 50 "C, red crystals of the corresponding p-amido-p-oxH-tetrachloride hydrate are formed (oxH = monoanion of oxalic acid). Treatment of this salt with perchloric acid gives a 1:l mixture of [(NH,),Co(p-NH,)(poxH)Co(NH,),](C10,),,2H20 and [(NH,),CO(~-NH,)(~-OX)CO(NH~)~] (C10,),,2H20.607 The preparation and properties of [(NH,),Co(p-OH),(p-a~)Co(NH,),1~'(ac = HCO,, MeCO,, CHCI,CO,, CH,ClCO,, CCl,CO,, + CH,FCO,, CHF,CO,, or CF3C0,) and [(NH,),CO(~-OH)(~-~C),C~(NH,), (ac = CH,ClCO,, CHCl,CO,, CCl,CO,, or CF,CO,) have been reported. The dithionate salt of the tetranuclear cation [ C O , ( C ~ O ~ ) ( O H ) , ( N H ~ ) ~ ~ ] ~ + was also prepared and structure (108) is proposed. The complex reported by Werner as [Co,(OH),(O,CMe)H,O(NH,),]Br, has been found to be [(NH,),-

,

Co(p-OH),(p-0,CMe)Co(NH3)3]Br,,HAc.608

The cation [(NH,),CO(~-CO,)CO(NH,),]~+has been prepared and characterized as its sulphate, chloride, nitrate, and perchlorate and [(Co(acac),] when treated with NaN, in glacial acetic acid followed by H 2 0 2 at 25°C gives a green compound formulated as [(acac)2Co(p-N,),Co(acac),J , acetic acid being employed in the preparation to prevent formation of the p-hydroxy-compound. In CHCl,, the compound possibly exists in the two 603 604 '05

'06

607 608

609

U. Thewalt, Chem. Ber., 1971, 104,2657. G. Tauzher and G . Costa, J . Inorg. Nuclear Chem., 1972, 34, 2676. W. P. Schaefer and R. A. Lighty, Acta Cryst., 1972, B28, 1777; U. Thewalt and R. E. Marsh, Inorg. Chem., 1971, 10, 1789. K. Wieghardt and G. Maas, Z . anorg. Chem., 1971, 385, 289; U. Thewalt, Acta Crysf., 1971, B27, 1744. K. L. Scott, M. Green, and A. G. Sykes, J. Chem. Soc. (A), 1971, 3651. H. Siebert and G. Tremmel, Z . anorg. Chem., 1972,390, 292. E. Kremer and C. R. P. MacColl, Znorg. Chem., 1971, 10, 2182.


272

isomeric forms (109) and (1 10): however, in DMSO, trans-[Co(acac),N,(DMSO)] is formed.610 N

N N (109)

(ll0)

1.r. evidence has been presented indicating that the complex [Co(NH,),CI,], first reported by Werner, should in fact be formulated as

Other Compounds. Treatment of [Co(CN),(OP(OEt),]]"- with NCO- in methanol at room temperature gives [CO(CN),NCO]~-, which was isolated as its potassium salt. The N-bonded isomer is the predominant, if not exclusive The structure of K,[Co(CN),] has been reported.613 [Co(chel)(PR,),]' (chel = bipy or phen) reacts with hydrogen to form [Co(chel)(PR,),H,]' (R, = Et,. Et,Ph, Ph,, or Bu,) which have the cis-configuration. The complexes undergo reductive dehydrogenation, which is accelerated by light. and catalyse the hydrogenation of butadiene to b u t e n e ~l 4. ~ When CoCl, is treated with bipy in methanol followed by addition of Me,SiCH,I. NaBH,. and NaC10,. red crystals of [Co(bipy),(CH,SiMe,),] C10, are formed in 70 yield.6l 5 Treatment of [(rr-Me,Cp)Co(CO),] with 1, in light petroleum gives a 75 "/, yield of [(n-Me,Cp)CoI,(CO)] (a Co"' carbonyl complex) and, when this is refluxed in light petroleum, black crystals of [(nMe,Cp)CoI,] are formed (90 '4 yield). The di-iodo-complex is insoluble in non-co-ordinating solvents, and in donor solvents gives [(x-Me,Cp),Co] and Co". Treatment of the black complex with Ph3P or py(L) gives [(rr-Me,Cp)COI,L].6 Boro-benzene complexes of cobalt are unknown, although [(IT-Cp)Co(n-C,H,BPh)]+ has been reported (see Vol. 1, p. 168). It has now been found Of',

+

610 611

61z 613

61s

616

D. R. Herrington and L. J. Boucher, Inorg. 'Vuclear Chem. Letters, 1971, 7. 1091. K. Wieghardt and H. Siebert, Z. Naturforsch.. 1972, 27b, 349. M . A. Cohen, J. B. Melpolder, and J. L. Burmeister, Znorg. Chim. Acta, 1972,6, 188. E. C. Reynhardt and J. C. A. Boeyens, Acta Crysr., 1972, B28, 524. A. Camus, C. Cocevar, and G. Mestroni, J. Organometallic Chem., 1972,39, 355. B. Wozniak. J. D. Ruddick, and G. Wilkinson, J. Chem. SOC.I A ) , 1971, 3116. D. M. Roe and P. M. Maitlis, J. Chem. SOC.(A), 1971, 3172.

Elemcnts of the First Transitional Period

273

that the reaction of [(z-Cp),Co] with organo-boron dihalides and boron trihalides in hexane or toluene at temperatures ranging from -80 to 20°C gives both [(n-Cp)Co(n-C,H,BR)]+ and [(IT-C,H,BR),Co] (R = Ph, Me, Br, OH, or OMe).617The sandwich nature of the compounds has been confirmed by an X-ray study on [(7r-CsH,BOMe),Co] (112) and Co-C and Co-B are found to be 2.057-2.248 A and 2.348 A, respectively.6' * [(~c-Cp)Co'~'(~c-(3)-1.2-

CO

dicarbollyl}] when heated to 600--700°C in the vapour phase forms six new isomers of the complex which can be separated by t.1.c. The isomers result from the migration of carbon atoms of the dicarbollyl ligand over its polyhedral surface.619The reaction of K[(B9C2H, 1)2Co'1']with CS, and AIC1, gives [{(B,C,H,,),S,H]CO~~']. An X-ray study reveals the product to have a sandwich structure with the metal ion between two mutually staggered 1,2-dicarbollide ligands and bonded symmetrically to the five atoms of each basal pentagonal face. The two icosahedra are linked by a S-CH-S bridge which spans B-8 and B-8'.620 y-Irradiation of cobalt(II1) complexes is reported to give reduction of lowspin cobalt(r1)species.62' Cobalt-Oxygen Compounds.-Reversible oxygenation of [Co(bzacen)] in solutions containing bases to produce [Co(bzacen)(base)O,] [bzacen = NN'ethylenebis(benzoylacetoniminate)] is found to occur under similar conditions to those reported by Basolo and Crumbliss for [ C ~ ( a c a c e n ) ] .Cobalt(rr) ~~~ complexes of salen, 4,6-Me2salen (substituents on the aromatic ring), saloph (increase in conjugation within the equatorial ligand), napsalen and napsaloph (increase in the aromaticity of the equatorial ligand) and amben (N4donor set instead of N,O,) have been prepared, and their uptake of oxygen studied, by Abel et al. All the oxygen adducts show very similar e.s.r. spectra and are relatively insensitive to the changes in the equatorial ligand outlined above.623 617 618

'19

621 622

623

T

G . E. Herblich, G. Greiss, H. F. Heil, and J. Miiller, Chem. Comm., 1971, 1328. G. Huffner and B. Krieg, Angew. Chem. Internat. Edn., 1972, 11,42. M. K. Kaloustain, R. J. Wiersema, and M. F. Hawthorne, J . Amer. Chem. Soc., 1971, 93, 4912. M. R. Churchill and K. Gold, Znorg. Chem., 1971, 10, 1928. S. Fujiwara, T. Watanabe, and H. Tanado, J. Coord. Chem., 1971, 1, 195. J. D. Landels and G. A. Rodley, Syn. Inorg. and Metal-org. Chem., 1972, 2, 65. E. W. Abel, J. M. Pratt, and R. Whelan, Inorg. Nuclear Chem. Letters, 1971, 7, 901.

274


However, a Russian group have reported that derivatives of [Co"(salen)] do not take up oxygen and in fact are tetrahedral in the solid, based on e.s.r. measurements. In solution, at low temperature, the equilibrium between tetrahedral and planar co-ordination is shifted towards the latter as the basicity of co-ordinated solvent molecules is increased and the monomeric planar molecules do take up An e.s.r. study has been made of [Co(salen)] in the solvents dimethylacetamide. CH,Cl,-toluene (1 :1) (both A-type), dimethylacetamide containing NCS- ions. DMSO. and pyridine-toluene (1:1.) (all B-type). In the A-type solvents, the electronic configuration is d;Z df, d:,, d,'* d t 2 - y 2 and in B-type solvents it is d;z d:Z d:, d i y d:2--).2. This is correlated with oxygenation of [Co(salen)] in these solvents, for in the A-type solvents there is no uptake of oxygen, and in the B-type the p-peroxy-species are formed at room temperature under one atmosphere of oxygen.h24u The first structural data have been published for a stable mononuclear cobalt-oxygen compound: [Co(02)(diphos),]BF,,2C,H, is prepared by oxygenation of [Co(diphos),]BF, [diphos = cis-1,2-bis(diphenylphosphin0)ethylene] and the product is diamagnetic. The structure (113) can be viewed as distorted trigonal-bipyramidal co-ordination with the 0, ligand in the equatorial plane and its molecular centre defining one co-ordination site. The relevant bond lengths are Co-0 = 1.871 and 1.902A and 0-0 = 1.420 A.625 P

The new complexes [L,Co"'(O: -)Co"'L,] (L = ornithine, 2,4-diaminobutyric acid, or 2,3-diaminopropionic acid) have been prepared by oxygenation of cobalt(i1)complexes at room temperature. When L = ornithine, oxygenation is reversible, but for the other two ligands, it is irreversible.626The structures of the p-d ioxo-complexes, rac- [Co(en),( p - 0 2)( p-NH ,)Co(en),] (NO3)4, H O6 and [LCo(p-O,)CoL]PhMe (L = 3,3'-diaminodi-n-propylamine-bis-salicylaldehyde)628have been reported. In the latter. 0-0 = 1.45(2)& typical of the p-peroxo-linkage, and in the former 0-0 = 1.35 A. which is characteristic of

,

Y. V. Yabalokov, V. K. Voronkova, V. F. Shishkov, V. A. Kogan, and 0. A. Osipov, Russ. J . Inorg. Chem., 1972, 17, 214. 624a E.-I. Ochiai, J . C . S . Chem. Comm., 1972,489. 6 2 5 N . W . Terry, E. L. Arnma, and L. Vaska, J . Amer. Chem. SOC.,1972,94. 653. 626 M . Munakata, Bull. Chem. SOC. Japan, 1971, 44, 1791. 6 2 7 U. Thewalt and R. E. Marsh, Inorg. Chem., 1971, 11, 351. 6 2 8 L. A. Lindblorn, W. P. Schaefer, and R . E. Marsh, Acta Crysf., 1971, B27, 1461. 624


275

a superoxo-bridge. Both the Co-0-0-Co--NH, ring and the Co-0 ~0-Co linkage of the two complexes are non-planar. The complexes [LCo(p-O,)(p-OH)CoLI3 [L = en, trien, dien, tetraethylenepentamine, or tris-(2-aminoethyl)amine] have been studied,629 and the new complexes [ ~Co(imidazo1e)(g1y),),0,],4H20 [(Co,(imidazole),(gly),O, } OH],3H2 0,and [Co(imidazole)(gly),(O,)H, 01have been prepared!30 The spectroscopic properties of various y-peroxo- and p-superoxo-cobalt(r1r) complexes have been examined. The singly-bridged p-peroxo-compounds have a strong band at 300 nm, whereas this falls at 350 nm for p-peroxo-p-hydroxocomplexes and two peaks at 480 and 700 nm are observed for p-supcroxospecies.63 The i.r. spectra of p-peroxo-bridged complexes of cobalt(r1r)cyclam have been reported.632 Oxides-The new oxocobaltates, M,CoO, (M = K, Rb, or Cs), Li,CoO,, ‘Li60C018048’,and M,Co,O, (z z 3 ; M = K, Cs, Rb, or Na) have been reported and their structures Ba,CoO, is prepared from CoCO, and Ba(OH),,8H,O at 1050°C in air. It is not isotypical of this class of compounds with a Ba,TiO, structure, but has a structure of the P-K,SO, type.634 +

Other Compounds.-Skutterudite, CoAs,, has cobalt octahedrally surrounded by six arsenic atoms, the latter forming rectangles.635 5 Nickel Carbonyl, Nitrosyl, and Nitrogenyl Compounds.--[(n-Cp)NiLX] (L = PPh,, PPh,Me, PPhMe,, or PMe,; X = C1 or Br) reacts with Na[Fe(CO),(n-Cp)] to form (114), which on treatment with stannous chloride gives (1 1 5).63(’

0 C

/ \ / (n-CP)- Ni -Fe

L

co I

,(n-CP) Fe nCl!

‘co

Treatment of [(K-Cp)Ni(CO)], with germanium(rv) and tin(rv) halides yields [(n-Cp)Ni(CO)MX,] (M = Ge, X = CI, Br, or I; M = Sn, X = Cl or Br) and [(n-Cp)Ni(CO)],MX, (M = Ge, X = C1; M = Sn, X = Br).162 629

630

631

632 633 634 635

636

M. Zehnder and S. Fallab, Helv. Chim, Acta, 1972,55,1691; R. Nakon and A. E. Martell, J. Amer. Chem. Soc., 1972, 94, 3026; J . Inorg. Nuclear Chern.. 1972,34, 1365. B. Jezowska-Trzebiatowska, A. Vogt, H. Kozlowski, and A. Jezierski, Bull. Acad. polon Sci., SPY.Sci. chim., 1972, 20, 187. Y . Sasaki, J. Fujita, and K. Saito, Bull. Chem. SOC.Japan, 1971, 44, 3373. C. K. Poon, Inorg. Chern., 1971,5,322. M. Jansen and R. Hoppe, Naturwiss., 1972, 59, 215. H. Mattausch and H. Muller-Buschbaum, Z. anorg. Chem., 1971, 386, 1. N. Mandel and J. Donohue, Acta Cryst., 1971, B27,2288. K. Yasufuku and H. Yamazaki, J. Organometallic Chem., 1972,38, 367.

276


The structure of [(dia~etylbis(dimetfylhydrazone))Ni(CO)~]shows the nickel atom to be in a distorted tetrahedral environment (1 16).637[Ni(acac),] C

.C

reacts with Et,Al and (PhO),P to produce [Ni{ P(OR),},] which, on carbonylation. gives either [Ni(CO)(P(OPh),},] or [Ni(CO),(P(OPh),},] depending on the conditions employed. Thus this reaction constitutes a good method for preparing the mono- and di-carbonyl products in high yield and Ni(CO), reacts with ( B U * ) ~ P F(,n- ~= 1 or 2) in pentane to produce the complexes [Ni(CO),L]. [M(CO),L], cis-[M(CO),L,], and cis-[M(CO),L,] (M = Cr. Mo, or W) complexes have also been prepared, and it has been proposed that the parameter J I J , ( J = J , - J , ; J , = P-F or P-H coupling constant in the complex. J , = P-F or P-H coupling constant in the free ligand) is a measure of the n-donor strength of the metal."' The reaction of [Ni(CO),(PMe,),] and I,, or of [Ni(PMe,),I,] and CO gives [Ni(CO)(PMe,),I,] which is reported to be the first dihalogeno-nickel carbonyl compound. A trigonal-bipyramidal structure is suggested with axial phosphine ligands."' [Ni(CO),L,] ( L = PPh,, PPh,Me. or PPhMe,) reacts with NOPF, in met hanol-t oluene to form [Ni( N 0 ) L ]PF, , and [Ni(CO), ( P P h ,),I. when treated with the same reagent in benzene. gives [Ni(NO)(PPh,)JPF, and a red-brown complex tentatively formulated as [Ni(NO)(CO)(PPh,),]PF,. [Ni(NO)(PPh,),]PF, reacts with CHCl,. (RO),P, and X - (X = Br or I) to give [Ni(NO)(PPh,),CI], [Ni(NO)(PPh,),{P(OR),}]PF,, and [Ni(NO)(PPh,),X]. respectively, whereas reaction with methoxide in stoicheiometric quantities gives [Ni(NO)(PPh,),OMe]. However. the reaction with excess methoxide gives as yet uncharacterized products.361 The structure of [Ki(PPh,),(NO)N,] has been reported. The metal atom is pseudo-tetrahedral and the nitrosyl linkage is bent (152.7")."41 [Ni(acac),] reacts with Me,Al and P(cyclohexyl), under nitrogen to give [{cyclohexyl),P},Ni2N,], the structure of which has been determined. The Ni-N-N-Ni system is linear with an N-N bond length of 1.12 A. Intermediate nickel-methyl compounds can be isolated from the reaction and the

,

637

H . D. Hansen and K . Krogman, Z . anorg. Chem., 1972,389, 247.

J. R . Olechowski, J . Organometallic Chem., 1971,32,269. 639 640

641

0 . Stelzer and R . Schmutzler, J . Chem. SOC.( A ) . 1971, 2867. M . Pankowski and M . Bigorgne, J . Organometallic Chem., 1972,35, 397. J . H . Enemark, Inorg. Chem., 1971, 10. 1952.


277

nitrogenyl dimer readily dissociates in toluene to [(cyclohexyl),P~,NiN2] and [{(cycl~hexyl),P},Ni].~~~The reactivity of the two-co-ordinate complex has been studied. but discussion of these reactions is included in the section on Nio compounds. Photolysis of Ni(CO), in a nitrogen matrix at 20K yields a new species, the i.r. spectrum of which is consistent with [Ni(CO),N,]."43 When pure nitrogen was sprayed on to a clean nickel surface at 20"C, i.r. evidence suggested the formation of Ni(N,)x (x probably equals 1 or 2).",

Halides and Pseudoha1ides.-(NH,),NiF, and (NH,)NiF, have been prepared. The former has a tetragonal structure, whereas the latter was isolated in both hexagonal and cubic forms.645The magnetic properties of both BaNiF, and Pb,NiF, have been studied.,, Fluoride complexes of Ni" have been studied by means of a fluoride-ion selective electrode: the complex [NiF(aq)]+ was detected.61The Ni2+-HCl-H20 system has been studied over a wide range of HC1 concentrations. Both NiCl, and [H,NiCl,] are formed.279Solutions of NiCl, in molten acetamide and caprolactam have been investigated by means of electronic spectroscopy. The nature of the Ni" species is independent of concentration up to about 0.3 mol 1-l. In both solvents Ni" occurs mainly in octahedral environments but at higher temperatures a tetrahedral species is formed.646Reaction of BBr, with anhydrous NiC1, yields anhydroti\ nickel(1r) bromide.281 1.r. and Raman data for [Ni(CN)J3- suggest the anion to have squarebased pyramidal g e ~ m e t r y7.7~The structure of [Cd(en)Ni(CN),],2C6H, has been reported: [CdNi(CN),] units form infinite layers with bridging CN groups, ethylenediamine molecules bridge Cd atoms between two layers, and the benzene molecules are enclathrated in cavities in this host lattice.647Replacement of the cadmium in this compound yields the three new clathrates, [M(en)m{Ni(CN),]].nC,H, ( M 2 + = Ni2+, CU", or Zn2+. m = 2 or 3, n = 0.14-0.28).648 An i.r. study of Hofmann's clathrate, [Ni(NH,),Ni(CN),], 2C6H,, has been carried out, as the several previous studies reported are not entirely consistent and do not agree with the spectrum predicted on the basis of its known structure. It was found that spectra are very dependent on sample preparation, as benzene is fairly readily lost especially on evacuation of the KBr die, and this presumably explains the previous i n c o n s i s t e n ~ i e s . ~ ~ ~ Nickel(O).-The two-co-ordinate complex [Ni(P(cyclohexyl), 2] is prepared P},Ni,N,] in toluene. Its reactivity has been by dissociation of [ ~(cyclohexyl), studied and the reactions are outlined in Scheme 4.6"2[Ni(l,S-cod),] ( 1 , 5 642

643 644 645 646 64'

648 649

P. W. Jolly, K. Jonas, C. Kruger, and Y. H. Tsay, J. Organometallic Chem., 1971, 33, 109. A. J. Rest, J. Organometallic Chem., 1972, 40, C76. J. K. Burdett and J. J. Turner, Chem. Comm., 1971,885. A. Lule and 0. Schmidt-DuMont, Z. anorg. Chem., 1972, 389, 1. M. E. Stone and K. E. Johnson, Canad. J. Chem., 1971,49, 3836. T. Miyoshi, T. Iwamoto, and Y. Sasaki, Inorg. Chim. Acta, 1972, 6 , 59. A. Sopkova, J. Chomic, and E. Matejcikova, Monatsh., 1971, 102. 961. S. Akyuz, A. B. Dempster, R. L. Moorhouse, and N. Zengin, J.C.S. Cliem. Comm., 1972, 307.


278

cod = cyclo-octa-1.5-diene) reacts with phosphine at low temperature to give [Ni(PH,),], which is a solid below -40°C. 1.r. and Raman data have been presented for the p r o d ~ c t . ” ~The ’ reaction of NiBr, and Ph,PH was

Scheme 4

originally suggested to yield [Ni(PHPh,),(PPh,),]; however, the product has been shown to be [Ni(PHPh2)4].051Studies on NIL, [L = PPh,, (pMeC,H,),P, or (nt-MeC,H,),P] show that substantial dissociation to NIL, although no further dissociation was detected.652 and L occurs at 25 There have been recent reports that nickel(obphosphine complexes, NIL,, react with strong acids to yield [NiL,H]+ species. and that the reaction of [Ni(P(OEt),),] and HCN in benzene gives [HNi(P(OEt),),(CN)]. However, the reaction of HCN with [Ni(dpb),] in benzene gives firstly [Ni(CN)(dpb),,5], and then [Ni(CN),(dpb)], and the same reaction in ether gives only [Ni(CN)(dpb), j]2 and dpb [dpb = 1,4-bis(diphenylphosphino)butane]. No hydridospecies was detected and no hydrogen was evolved from the reactions. However. it is possible that [HKi(dpb)(CN)] and ([HNi(dpb),]+ are present in very small amounts and are very Methanolysis of [Ni(PCl,),] in hydrocarbon solvents is a slow heterogeneous oxidation-reduction process. Products typical of methanolysis of unco-ordinated PC1, are formed, including MeCl and (MeO),P(O)H. The oxidation product is [Ni(MeOH),]’+ and no hydrogen is formed. On the basis of a transient i.r. band at 1610 cm-’ (1135 cm- on deuteriation), a hydrido-nickel intermediate is suggested, although no high-field n.m.r. signal could be detected. When methoxide is the nucleophile. a high yield of [NifP(OMe),),] is obtained.654 A new general method of preparation of metal-PF, complexes using [Ni(PF,),] as the reactant has been reported.655The reactions performed and their products are given in Table 4.The structure of [ { [(cyclohexyl),P],CH,),Ni] shows the metal to have distorted tetrahedral co-ordination and the acute P-Ni-P angle of 77’ is suggested as indicating ‘bent’ Ni-P bonds.656 O C ,

,

’

650 651

652

653 654

”’ 656

M. Trabelsi. A. Loutelher, a n d M. Bigorgne, J . Organometallic Chem,, 1972, 40, C45. C. W. Weston, G . W. Bailey, J. H. Nelson, a n d H. B. Jonassen, J . Inorg. Nuclear Chem., 1972, 34. 1752. C. A. Tolman. W. C. Seidel. a n d D. H. Gerlach, J. Amer. Chem. Soc., 1972, 94. 2669. C. C. Corain, P. Rigo. a n d G. Favero. Inorg. Chem., 1971, 10, 2329. D. F. Bachman, E. D. Stevens, T. A. Lane, a n d J. T. Yoke, Inorg. Chem., 1972,11, 109. R. B. King and A. Efraty. J . Amer. Chem. SOC.,1971, 93, 5260; 1972, 94, 3768. C. Kruger and Y.-H. Tsay, Acra Cryst., 1972, B28, 1941.

Elements of the First Transitional Period Table 4

279

The reactions of[Ni(PF,),]

Reactant

Product

The crystal structure of [(n-C2H,),Ni(P(cyc10hexy1),}] has been reported and the nickel atom shows a highly distorted trigonal symmetry with a planar arrangement of l i g a n d ~ . ~The " reaction of [(Ph,P),Ni(C,H,)] with (CF,),CO in ether gives [(Ph,P),Ni * C(CF,),d], which can also be prepared by reaction of PPh, with [(lc-C,H,,)$ii.C(CF,),b]. The structure of this complex has been reported658and is interesting, in that the C O ' group is symmetrically bonded sideways to the metal (Ni-0 = 1.87 A. Ni-C = 1.89 A, C-0 = 1.32 A). The related complex [(Bu'NC),k * C(CF,),O reacts with (CF,),CNH to the structure of which has yield [(Bu'NC),Ni*C(CF,),NH~C(CF,),6,658" also been reported.658It has established that the imine inserts into the Ni-C bond on formation of the complex, the Ni-0 bond remaining intact. [Ni(O,)(CNBu'),] reacts with a variety of compounds and the reactions which are outlined in Scheme 5 can be classified as either atom transfer redox reactions, atom transfer oxidation reactions, oxidative substitution reactions or metal assisted peroxidation reactions.659An i.r. study of [Ni('80,)(CNBu'),] [Ni(CO),(CNBu'),] b

[Ni(NO)(CNBu'),] NO,

1 co

co

/O\

E [ Ni(O,)(CNBu'), ]A[ ( Bu'NC)?Ni Bu'NC' Bu'NC

'0

(Bu'NC),Ni /

trans-[Ni( CNBu'),(NO,),I

'

C=O]

o \ p

'o/'o Scheme 5

revealed the oxygen to be co-ordinated in a 'side-on' fashion, and force-constant calculations show a marked decrease in the 0-0 bond strength on co-ordinain free oxygen.660A tion to 3.0-3.5 mdyn A-' compared to 11.5 mydn k 1 C. Kruger and Y.-H. Tsay, J . Organometallic Chem., 1972,34, 387. R . Countryman and B. R. Penfold, Chem. Comm., 1971, 1598. 6 5 8 0 M. Green, S. K. Shakshooki, and F. G. A. Stone, J . Chem. SOC. ( A ) , 1971,2828. 6 5 9 S. Otsuka, A. Nakamura, Y. Tatsuno, and M. Miki, J . Amer. Chem. Soc., 1972, 94, 3761. 6 6 0 A. Nakamura, Y. Tatsuno, M. Yamamoto, and S. Otsuka, J . Amer. Chem. Soc., 1971,93,6052. 657

658


280

range of oxidative addition reactions of NIL, (L = Bu'NC or Ph,P) have been reported and are shown in Schemes 6 and 7.661 ROCOCl

+ [Ni(CNBu'),]

-+

[ROCONiCI(CNBu'),]

-1-c0, RCOX

+ [Ni(CNBu'),]

[RCONiX(CNBu'j3]-~[RNiX(CNBut),]

+

Bu' N

II

Bu'N

C -C =NBu

Bu'NC 'N(

'X

I

'

II

Bu'NC

C-C \ /

Ni

'X

\=C-f$-COR Bu'

X X

= =

I

=NBu'

b I- C - R Bu'

C1, R = Ph, I I = 2 C1,R = Me,n = 1

X X X

C1,R = Me = 1,R = Me = C1.R = PhCH, =

Scheme 6

RCOX

+ [Ni(PPh,),]

+ [Ni(PPh,),] ROCOCl + [Ni(PPh,),] RX

+

[NiX(COR)(PPh,),]

. -I

+[NiX(R)(PPh,),]

-, [NiCl(CO,Rj(PPh,),] (R = Me, Et, or CH,Ph) -R tPPh, -

co,

1

+ PPh,

[NiX(PPh,),] (X = C1, Br, or I ) Scheme 7

[Ni(PPh,),C,H,]. [Ni(CNBu'),]. or [Ni(l.S-cod)J reacts with (CF,),CN, at room temperature to give (1 17).662O n the basis of its reactivity, [(Bu'NC),-

(117) L = Bu'NC, PPh,, or

662

1,5-cod

5. Otsuka. M. Naruto, T. Yoshida, and A. Nakamura. J.C.S. Chem. Comm., 1972, 396. J. Clemens. R. E. Davis, M. Green, J. D. Oliver, and F. G . A. Stone, Chem. Comm., 1971, 1095.


28 I

Ni(azobenzene)]had been postulated as containing a n-N=N bond: a structural study confirms this. The structure is shown in (118); the N-N bond length of 1.385(5) 8, is longer than in the free ligand and very close to the single-bond length.663The structure of [Ni(PhC=CPh)(CNBu‘),] has also been reported and the acetylene ligand is also bonded ‘side-on’ to nickel. The co-ordination But

Bur /

\

N

\c

dN

\ / Ni

/ \

N-N

/

Ph

‘Ph (118)

is essentially planar and can be considered as trigonal if the acetylene is considered to be ~ n i d e n t a t e . ~ ~ , [Ni(l,S-cod),] reacts with R,AlX to yield [(R,AlX),Ni(l,S-cod)] [R = Me, X = SPh; R = Et, X = PPh: (R,AlX), = (Me,AlSCH,),], which contains the previously unreported AI-X-Ni linkage. However, [Ni(acac),] reacts with two moles of ,Me,AlSPh to give [Me,Al(acac)], [Al(acac),], and [Ni(SPh)2]n.665 Nickel(I).-[(n-Cp)Ni(PBu:),] +C1- reacts with NaS(CH,),, SNa (n = 2,4, or 6) in ethanol to give (119),”6” and with NaSR or NaSC,H,X to yield [(n-Cp)Ni(PBu”)SR] (R = H, Me, Et Pr”, Bu”, CH,Ph, CH,CO,H, or COMe) and [(n-Cp)Ni(PBu,”(S.C,H,X] (X = p-Me, p-C1, p-N02, or p-COMe).66’ (7F -Cp)

Bu;P

\

(x-Cp)

Ni - S-( CH,),

/

(119)n

=

S - Ni

\

PBu:

2,4,or6

The structure of [(n-Cp)Ni(MeNC),Ni(n-Cp)] has been repor tcd. The Ni-Ni bond is short at 2.322 A.668 NickeI(II)..-CComplexes. A detailed examination of the cr! \tal field description of tetragonal nickel(@ complexes6‘”’ revealed the possible existence of 3Eg and 663 664

665

666

667 668 669

R. S. Dickson, J. A. Ibers, S. Otsuka, and Y . Tatsuno, J . Amer. Chern. SOC.,1971, 93, 4636. R. S. Dickson and J. A. Ibers, J . Organometallic Chem., 1972, 36, 191. T. Hirabayashi and Y . Ishii, J . Organornetallic Chem., 1972, 39, C85. F. Sato, T. Yoshida, and M. Sato, J . Organometallic Chem., 1972, 37, 381. M. Sato and T. Yoshida, J . Organometallic Chem., 1972,39, 389. R. D. Adams, F. A. Cotton and G . A. Rusholme, J . Coord. Chem., 1971,1,275. J . C. Donini, €3. R. Hollebone, and A. B. P. Lever, J . Amer. Chem. SOC.,1971, 93, 6455.

282


ground states. as well as the more usual 'Big terms. On this basis it has been suggested that it may be possible to form high-spin square-planar nickel@) complexes with a 3 E g ground state, but the formation of such complexes would be very dependent on the nature of the ligands, good n-donor ligands being essential. The effect of pressure on ligand-field spectra of five-co-ordinate nickel(l1)complexes reveals that those of trigonal-bipyramidal geometry show extremely pressure-dependent spectra, whereas the spectra of square-pyramidal species are less pressure-dependent. Thus this may be used as a method of distinguishing between the two geometries.670 Pyridiiie and related ligands. [Ni(py)2(H,0)2(N0,),] has been shown by X-ray crystallography to be six-co-ordinate and to contain unidentate nitrate groups.67 The far-i.r. spectra of the complexes [Ni(py),(NO,),] have been examined with a view to determining which of the reported stoicheiometries exist. The complexes with x = 3 and 6 were confirmed.386 The cation [Ni(2NH,py),]'+ has been shown to be octahedral by X-ray The complex ion [Ni{(py),(tarne))]'+ has been isolated from a template reaction of pyridine-2-carboxaldehyde and 1,1,1 -tris(aminoethyl)ethane. The ligand is sexidentate. O 5 Nickel(i1) complexes of the potentially quinquedentate ligand (pydpt) derived from pyridine-2-carboxaldehyde and bis-(3,3'-aminopropyl)amine have been prepared. The complexes [Ni(pydpt)X]X, [Ni(pydpt)Y]PF, (X = C1, Br, I, NO,, or SCN: Y = C1, Br. NO,, or SCN), and [Ni(pydpt)H,O](PF,), were isolated and all have pseudo-tetrahedral co-ordination both in the 2,6-(Dibenzothiazol-2-yl)pyridine (120; NNN) reacts solid and in with appropriate metal salt in EtOH-CHCl, to give [Ni(NNN)Cl,] and [Ni(NNN)(NO,),], both of which are ~ c t a h e d r a l . ~ ,

(120)

The complexes d-[Ni( bipy),](ClO,),,H,O and d-[Ni(phen),](C1O,),,2H2O have both been found to racemize when heated in the solid state, the racemization occurring after dehydration has taken place. Activation energies have been calculated for the racemization processes.239 The reaction of [NiEt,(bipy)] with C1,SiH in ether at temperatures between - 5 and -40°C for 1.5 h gives the yellow-brown complex [Ni(SiCl,),(bipy)] in 8 5 % yield, as well as EtSiX,, H,, and C,H,. With MeSiC1,H at -40 to -3O"C, an 84% yield of [Ni(SiCl,Me),(bipy)] is obtained.674The thermal decomposition of [Ni(quin),-

6'3

J. R. Ferraro. D. W. Week, E. C . Siwiec. and A. Quattrochi, J . Arner. Cltem. Suc.. 1971,93, 3862. A . F. Cameron. D. W. T a y l o r . and R. H . hurtall. J.('.S. Dalron, 1972, 422. K. Seff. Acta Cryst.. 1972, B28. 2298. C. T. Spencer and L. T. Taylor. Inorg. Chem., 1971. 11. 2407.

674

Y . Kiso, K. Tameo. and M.Kumado. Cheni. C o n i ~ .1971, . 105.

670 671

67z

EIements of the First Transitional Period

283

(NCS),],2H20 (quin = quinoline) gives two isomers of [Ni(quin),(NCS),] but anhydrous [Ni(quin),(NCS),] was not ~ b s e r v e d . ~6-Methyl-2,3-di-(6’-methyl2’-pyridy1)quinoxaline (dpq) and its 6,7-dimethyl analogue (dmpq) form the tetrahedral complexes [Ni(dpq)X,] (X = C1, Br, or I) and [Ni(dmpq)X,] (X = Br, or I) and [NiCl,(dmpq)], which is ~ c t a h e d r a l . ~However, ” the reaction of either 6-methyl-2,3-di-(2’-pyridyl)quinoxaline(dpmq) or its 6,7-dimethyl analogue (dpdmq) with nickel@) halides in ethanol yields NiX,L (L = dpmq, X = C1, Br, or I; L = dpdmq, X = Cl or Br) and [NiI,(dpdmq)(H,O),] all of which have octahedral ~ o - o r d i n a t i o n . ~1.r. ’ ~ and magnetic studies of [Nix,(pyrazine),] (X = Cl, Br, or I) show the compounds to have structures similar to those of their cobalt@) analogues.393The octahedral complexes NiX,L and NiX,L, (X = CI, Br, or SO,; L = pyridazine, phthalazine, or 3,4-benzocinnoline) have been isolated.393 Arnine and related complexes. The thermal decomposition of NiF,,6NH3 has been [Ni(allylamine),SO,] has been isolated,381 as have the complexes [NiL,X,](L = 0-,m-, or p-toluidine, anisidine, or phenetidine, X = Cl, CNS, or The latter series of compounds all have six-coordinate structures with bridging X groups. N-Benzylethylenediamine (L’) and NN’-dibenzylethylenediamine (L’) form the high-spin compounds, [Ni(L’),(NCS)(N03)]. [Ni(L’),(NCSe)(NO,)], [Ki(L2),(WCX),] (X = S or Se). The complexes of the monosubstituted diamine are octahedral, whereas those of its disubstituted analogue are tetragonaI3*, Mixed chelates of nickel(I1) with NNN’N’-tetramethylethylenediamine (tmen) and some j3-diketonates have been prepared; they are of two types:676firstly, the red diamagnetic squareplanar complexes, [Ni(tmen)(acac)]X, and [Ni(tmen)(bzacac)]X, &X = C10, or BPh,) and, secondly, [Ni(tmen)(P-dik)(OH,),]ClO,, [Ni(tmen)(P-dik)NO,], and [Ni(tmen)(P-dik),](P-dik -= acac or bzacac) which are all green, paramagnetic, and octahedral. In solution the equilibrium : red-[Ni(tmen)(p-dik)]

+

+ 2s + blue-[Ni(tmen)(P-dik)S,]

+

is set up, the red form predominating in inert solvents and at high temperature, the blue form in co-ordinating solvents or at low temperature. The equilibrium: [Ni(tmen)(P-dik)(NO,)]

+ 2s + [Ni(tmen)(P-dik)S,]+ + NO;

has also been observed. The Quincke method of magnetic susceptibility measurements has been adapted to perform magnetic titrations, the technique being used to study nickel@) complex formation by C-substituted ethylenediamines. It was found that for en and 1,2-propanediamine, paramagnetic [NiL3lZf complexes are formed with no evidence being obtained for intermediate stages. However, complex in 2-methyl- 1,2-propanediamine gives a paramagnetic [NIL,] +

675

T. Sramko and E. Jona, Colt. Czech. Chem. Comm., 1972,37, 1645. Y . Fukuda and K . Sone, J . Inorg. Nuclear Chem., 1972,34, 2315.


284

the presence of excess L, but when Ni :L = 1 :2 a diamagnetic complex is formed and 2,3-dimethyl-2,3-butanediamineforms only the diamagnetic bis-complex, there being no evidence for further interaction. meso- 1,2-Diphenylethylenediamine in 50% aqueous dioxan gives a mixture of the paramagnetic NiL” and diamagnetic [NiL2I2 complexes.677The high-spin complexes [Ni(dpt)L]X, (L = en or pn. dpt = 1,5.9-triazanonane. X = Ci. Br, I, or C10,) and [Ni(dpt)L(NCS)](CNS) have been isolated. in which the metal atom is probably square-pyramidal in all cases with the exception of [Ni(dpt)L]I, (L = pn), which probably has intermediate five-co-ordinate geometry, and the thiocyanate complex which is ~ i x - c o - o r d i n a t e .The ~~~ shows both cations to be structure of [Ni(pn),][Ni(pn),(H,0)2]C14,H,0 octahedral.679The occurrence of stable square-planar N-bonded complexes [M(Et,dien)NCX]BPh, (M = Ni or Cu. X = P. Se, or S) has been contrasted with the N- to X-bonded re-isomerizations which have been observed for the corresponding Pd complexes. The related [Ni(Et,dien)(NCX),] complexes exhibit a variety of geometries. When X = 0, the complex is fiveco-ordinate in the solid and in MeCN; when X = s, the solid compound is dimeric with bridging NCS groups, but exhibits a mixture of four- and fivtco-ordinate geometries in MeCN: when X = Se, four-co-ordination is observed both in the solid and in MeCN.383[Ni(trien)(en)]X, (X = C1, Br, I, SCN, NO,. OAc, ClO,, or BPh,) complexes have been reported; they are octahedral both in the solid and in solution.680[Ni(trien)](CIO,), has planar co-ordination of the nickel atom, the four nitrogens being in a trapezoidal array. The perchlorate ions are not co-ordinated but are hydrogen-bonded to the ligand.681The complexes (121) have been studied by electrochemical methods, and the four-membered series, z = - 2, - 1,0, + 1 is indicated.68z[Ni(daco),](C10,),,2H20 (daco = 1,5-diazacyclo-octane) has strictly square-planar coordination.683 The complexes [NiLXz] (L = NNN’N”N’”N”’-hexamethyl3,6-diazaoctane-l&diamine, X = CI, Br, NO,, SCN, CIO,, or BPh,) have been +

z

(121) 677 678 619 680

681

682 683

(123) R = H, 2-Me, 3-Me. 4-Me;or 4 - M e 0

G . R. Graybill, J. W . Wrathall, and J . L. Ihrig, Inorg. Chem., 1972, 11, 722. G. Ponticelli and C. Preti, J.C.S. Dalton, 1972. 708. G. D . Andretti, L. Cavalca, and P. Sgarabotti, Gazerta, 1971, 101, 494. E. Cara, A . Cristini, A. Diaz, and G. Ponticelli, J.C.S. Dalton, 1972, 527. A. McPherson, M. G . Rossman. D. W. Margerum, and M. R. James, J . Coord. Chem., 1971, 1, 39. E. B. Fleischer, A. E. Gebala, and P. A. Tasker, Inorg. Chim.A c f a , 1972, 6, 72. D . J. Royer, V. H . Schievelbein, A. R. Kalyanaraman, and J. A. Bertrand, Znorg. Chim. &a, 1972, 6. 307.


285

isolated. When X = C10, or BPh, they are square-planar, the others are octahedral.684 The complexes (122) have been prepared.685 The heats of formation of Ni" complexes of 1,5,9,13-tetra-azatridecaneand 3,7-diazanonane-1,g-diamine have been reported.686 The temperature-dependent equilibrium between paramagnetic and diamagnetic forms of the nickel(I1) complex of the quadridentate ligand 2,12dimethyl-3,7,11,17-tetra-azabicyclo[ 11,3,1]heptadeca-l( 17),2,11,13,15-pentaene has been studied in water, MeOH, DMF, DMSO, and MeCN. The diamagnetic form is the thermally more favoured at higher temperatures, and the measurements are consistent with a square-planar + octahedral equilibrium. Similar measurements have been performed in H,O and DMF on the analogous complex in which a methyl group replaces the secondary amine hydrogen on the ligand.687The dianionic quadridentate Schiff bases derived from 2-pyridylhydrazine and 1,2-diones (123) form dimeric nickel@) complexes which show significant Ni-Ni bonding and may be readily oxidized. Thus red diamagnetic [Ni,L,],2C6H6 [R' + R2 = (CH,),] is obtained and a structural

study shows each nickel to be bonded in an essentially planar array to four nitrogens, three of which are part of one quadridentate ligand and the fourth is part of the other. The terminal pyridyl groups bridge to the second nickel atom and Ni-Ni = 2.81 A. The complex undergoes four electrode reactions which may be summarized as : +2-+l,+l+O,O+-l,-1~-2

and treatment with AgPF, in CH2C12'gives [Ni2L2]PF6,2CH2C12.688 The trihydrate shows structure of NN'-di-(2-aminoethyl)malondiamidatonickel(11) the four nitrogen atoms to be bonded to the metal in a trapezoidal array giving distorted square-planar ~ o - o r d i n a t i o n .The ~ ~ ~i.r. spectrum of NiC1,,2AAB 684 685

686 687 6BB

689

A. Cristini, G. Ponticelli, and A. Diaz, J.C.S. Dalton, 1972, 1361. S. V. Serbina, V. P. Kurbatov, and 0. A. Osipov, Russ. J . Inorg. Chern., 1971. 16,578. L. Fabbrizzi, R. Barbucci, and P. Paoletti, J.C.S. Dalton, 1972, 1529; R. Barbucci, L. Fabbrizzi, and P. Paoletti, ibid, p. 745. L. Rusnak and R. B. Jordan, Inorg. Chern., 1971, 10, 2199. N. A. Bailey, T. A. James, J. A. McCleverty, E. D. McKenzie, R. D. Moore, and J. M. Worthington, J . C . S .Chern. Cornrn., 1972, 681. R. M. Lewis, G. H. Nancollas, and P. Chppens, Inorg. Chern., 1972,11, 1371.


286

(AAB = p-aminoazobenzene) shows the ligand to be unidentate and bonded via the a m i n o - g r ~ u p . ~ " Irnidazole and pyrazole ligands. The thermal decomposition of [Ni(imidazole),]X, gives Ni(imidazole)X, (X = C1, Br, or I).396 The complexes [Ni(2-Meimid),]X, (X = C10, or BF,, n = 4 or 6 ) have been prepared and are all squareplanar,74however, [Ni(N-Bu"imid),]X, (X = C1, Br, I, or NCS, n = 2,4, or 6 ) are either pseudo-octahedral (n = 4 or 6 )or tetrahedral ( n = 2).75The complexes [NiL,]X,,nH,O, (X = C1, n = 2 ; X = NO,, n = 3). NiL,X, (X = C1, Br, or I) and NiL,X,,H,O (X = C1 or Br) [L = 2-(2'-pyridy1)imidazolel have been d e ~ c r i b e d90. ~ 2-Methylbenzimidazole (L) farms the complexes NiL2X, (X = C1, Br, or I) which are all ~ s e u d o - t e t r a h e d r a l2-Benzylbenzimidazole .~~~ (Dibaz) forms the complexes [Ni(Diba~),X,].~~' When X = SCN, the complex is dimeric with bridging SCN: when X = C1 or Br, octahedral or pseudo-octahedral structures are adopted: when X = I, the complex is square-planar. The ligands 242'pyridy1)benzimidazole (L') and 2-(2'-pyridy1)imidazoline (L2) form the complexes Ni(L')3X, and Ni(L2),X, (X = C1, Br, I, or NCS). All the complexes are high-sphSoo Pyrazole (pz)and 3(5)-methylpyrazole (mpz) react with metal salts in acetone or ethanol in a variety of molar ratios, yielding [Ni(pz),X,], [Ni(pz),(NO,),], and [Ni(mp~),(NO,),,].~o Macrocyclic N-donor ligands. Nickel complexes of macrocyclic ligands have been studied by cyclic voltammetry, and the irreversible or quasi-reversible Ni'L have been established.244 The structure couples: Ki"'L =: Ni"L of (124) has been reported and the co-ordination is essentially square-planar with a slight tetrahedral distortion.692 The reaction of [Ni(pn)J2+ with

HAH

diacetone alcohol in methanol gives small yields of (125); however, if diacetone alcohol is used as the solvent as well as the reactant, (126) or an isomer of this complex is formed. The reaction of [Ni(pn),I2+ with anisoin or benzoin in MeOH gives (127), whereas reaction with acetoin gives a complex containing primary amino-groups. which is high-spin and octahedral. Three possible 690 691

R . J. Dosser and A . E. Underhill, J . C . S . Dalton, 1972, 61 1. M . V. Artemenko, E. A. Christyakova, P. A. Suprunenko, and G . I. Kal'naya, Russ. J . Inorg. Chern.. 1971, 16, 1026.

692

M. F. Richardson and R . E. Sievers, J . Amer. Chern. SOC.,1972,94,4134.

28 7


structures involving sexidentate ligands have been proposed.693 A ‘H n.m.r. study of (128) and (129) has been made. Selective deuteriation facilitated assignment of the spectra and the chelate rings undergo rapid flexing, causing pairs of

n (125) (126)

(127) R

(128) X = ClO,, PF,, or NO,

=

H or M e 0

(129)X = ClO,, PF,, or NO,

gem-methyl groups to become equivalent.694The structure of (128; X = C10,) has been reported and there are slight deviations from planarity of co-ordinaof (129) with nitric acid yields (130), whose structure has t i ~ n . ~Oxidation ~’ also been reported. Again, the co-ordination deviates slightly from a true plane, indicating the lack of flexibility of the tetra-aza 1igand.b” The structure of the related complex (131) shows that in the complex cation the two secondary 693 694

695

696

D. St. C. Black and H. Greenland, Austral. J . Chem., 1972, 25, 1315. V. L. Goedken and D. H. Busch, Znorg. Chem., 1971,10,2679. M. F. Bailey and I. E. Maxwell, J.C.S. Dalton, 1972, 938. I. E. Maxwell and M . F. Bailey, J.C.S. Dalton, 1972, 935.


288

amine and two imino-donors are trans-coplanar. The two asymmetric carbon centres and the two asymmetric nitrogen centres occur in racemic paiis, the configuration of the racemate being (1-RS, 3-SR, 8-RS, 10-SR).697The strucnickel(1r)d i p e r c h l ~ r a t e ~ ~ ~ tures of 3,3-dimethyl-l,5,8,ll-tetra-azacyclotridecane

(130)

(131)

and of (132) have been reported;699the latter is prepared by the reaction of methyl vinyl ketone with dien.HC1 in the presence of Ni(OAc),. Reactivity patterns paralleling those found for transition-metal corrole complexes have

(132) 697 698 699

D. A. Swann, T. Waters, and N. F. Curtis, J.C.S. Dalton, 1972, 1115. J. M. Waters and K . R. Whittle, J . Inorg. Nuclear Chem., 1972, 34, 155. J. F. Myers and C. H. L. Kennard, Chem. Comm., 1971,77.


289

been found for (133), which contains charge-delocalized six-membered rings. Thus, N-alkylation of the N-donor atoms as well as deacylation and reversible protonation of the meso C atom have been observed. The resultant N-alkyl groups are reactive being solvolysed in nucleophilic solvents. The reactions studied are outlined in Scheme K 7 O o Complexes of the isomeric cyclic tetramines. 2,4,4,9,11,ll-hexamethyl1,5,8,12-tetra-azacyclotetradeca1,5,8,12-tetraene and 1,4,4,9,9,ll-hexamethyl-1,5,8,12-tetra-azocyclotetra1,5,8,1Ztetraene have been prepared by HNO, oxidation of the appropriate (1,8- and 1,llrespectively) diene-NiI'complexes. Both cations can be reduced by borohydride or H,-Pt to reform the dienes; however, hypophosphorous acid reduces

Scheme 8

the 2,4,4,9,9,1l-hexamethyltetraenecomplex to the cyclic tri-iminemonoamine, 1,5,11-triene-nickel@) 2,4,4,9,9,11-hexamethyl-1,5,8,12-tetra-azacyclotetradecacomplex.701 Complexes of the strained macrocyclic ligand (134) have been prepared. The complex [NiL(NO,),],~H,O is octahedrai; however, [NiLCl,],tH,O and [NiLCl](ClO,),H,O [L = (134)] are the first nickel@) complexes containing '0°

C . J. Hipp and D. H. Busch, J.C.S. Chem. Comm., 1972,737. N. F. Curtis, J . Chem. SOC.( A ) , 1971, 2834.

290


a tetradentate macrocyclic ligand and having trigonal-bipyramidal structures. The large benzyl groups appear to prevent six-co-ordination being achieved in these cases, but not in the case of the nitrate. Ligand-field parameters indicate that ( 134) is only weakly ~ o - o r d i n a t e d . ’ ~ NN’-Bis-(2’-formyl-4’-nitro~

pheny1)-1,3-diaminopropane and its ethylene analogue have been used in reactions of Ni(OAc),together with en, pn, 2Me2-pn, 1,2-diaminocyclohexane, 1,8-diaminonaphthalene, or 1,2-diaminobenzene to give the macrocyclic compounds (135).402

NO,

(135)) I = 2 or 3, R = (CH,),, (CH,),, CMe,CH,, cyclohexyl, or o-C,H, n = 2, R = 1,8-naphthyl

A complete series of nickel(I1) complexes (136H139) has been produced wherein the macrocyclic ligands contain four N-donors and vary stepwise from containing one to four unsaturated N atoms. All the complexes are formally obtained by hydrogenation or oxidative-dehydrogenationof Ni(CR)2 (138). The complexes of (CR)and (CR + 4H) have been reported earlier. [(CR + 2H)I

+

’02

G. A. Kalligeros and E. L. Blinn, Inorg. Chern, 1972, 11, 1145.


29 1

Nil2+ is prepared either by reduction of [Ni(CR)I2+ or aerial oxidation of [Ni(CR + 4H)]* and [Ni(CR)I2+. Electrochemical behaviour of the entire series has been studied in MeOH and MeCN. The range of formal oxidation states Ni3+ to Nio has been obtained depending on the ligand.703 Nickel(I1) complexes of taab (140) can be reduced by hydrogen at relatively low pressure to give Ni(H,taab)X, in which the azomethine linkages have been hydrogenated.704 +

HN-Ni

-NH

(136)Ni(CR + 4H)'+

N-Ni

-N

(138)Ni(CR)'+

703 'OC

HN-Ni

-N

(137) Ni(CR + 2H)2+

N-Ni

-N

(139) Ni(CR-2H)' '

E. K. Barefield, F. V. Lovecchio, N. E. Tokel, E. Ochiai, and D. H. Busch, Znorg. Chem., 1972, 11, 283. V. Katovic, L. T. Taylor, F. L. Urback, W. H. White, and D. H. Busch, Inorg. Chem., 1972, 11, 479.

292


H,[MeHMe(en),] reacts with WOAc), to give the planar 12.n-macrocyclic complex [Nif MeHMe(en), ) ](141), treatment of which with trityl tetrafluoroborate in MeCN gives oxidative dehydrogenation to the 15.n-cation (142). This complex shows a paramagnetic monomer ;=t diamagnetic dimer equilibrium, and can be reduced to the neutral 16.n-complex (143) by BH, in ethanol and voltammetrically oxidized to the 14~-complex(144). The related 16.n-nickel complexes ( 145) derived from the recently reported dihydroocta-aza[ 14lannulene macrocycles have also been prepared. These and the 161~-complexes(146) undergo a two-electron oxidation presumably giving the 14.n-complexes(147) and (148). respe~tively.~~’

(144)

RZ


R'

293

w

Rs

The structures of the dihydro-octa-aza[ 14lannulene complexes (149) have been The second example of single macrocycles capable of encompassing two metal atoms has been p ~ b l i s h e d . " ~The complexes (150) and (151) have been prepared by metal template reactions of acetone and

N-Ni-N

I

I R' = Me, Et, or Bun R2 = (CH,), or

(149) R'

1,4-dihydrazinophthalazine. Both complexes are six-co-ordinate, non-planar, and it is suggested that the unco-ordinated hydrazine amine groups are bonded in the fifth and sixth positions to give a staggered stacking arrangement in a polymeric array. A detailed study of the electronic, vibrational, and e.s.r. spectra of a series of substituted dipyrromethane complexes of nickel(I1) has been The reduction of the nickel@) 1,19-diethoxycarbonyltetradehydrocorrin cation with a sodium film in T H F under high vacuum gives both one- and twoelectron reduction products. The one-electron reduction product is a very stable free radical, and the other product is formulated as a Ni" species with the two extra electrons located in ligand ~ t - o r b i t a l sThe . ~ ~structures ~ of nickel(rr)-o~taethylporphin~~~ and nickel@)-deoxophylloerythrin methyl ester-1,270s 706

J. E. Baldwin, R. H. Holm, R. W. Harper, J. Ruff, S. Koch, and T. J. Truex, Inorg. Nuclear Chem. Letters, 1972, 8, 393. W. Rosen, Inorg. Chem., 1971, 10, 1832. E. F. Meyer, Acta Cryst., 1972, B28, 2162.

294


(151) [Ni2(taph)I4+

dichloroeth me' O H have been reported. The former is square-planar and contains the shortest hl-N bond [1.929(3) A] yet found in a porphyrin complex and the individual pyrrole rings show marked non-planarity. and the latter shows a very slight ruffling of the square-planar co-ordination. Thermodynamic functions for the addition of substituted pyridines to nickel(I1)-porphyrin have been evaluated.-09 Other N-donor ligaizds. Nickel(I1) salts react with aqueous solutions of the sodium salts of 5-o-chlorophenyl-. 5-p-chlorophenyl-. 5-p-methoxyphenyl-, 5-p-chlorobenzyl-. and 5-phenyl-tetrazole to give octahedral The octahedral complexes Ni2L,Cl,H20 and NiL,(OAc),H,O [L = (152)] contain the ligand in its bidentate form, both nitrogens of the 2-pyridinaldimine system being ~ o - o r d i n a t e d Refluxing .~~~ a 70 04-aqueous methanol solution of phthalimide (L'). succinimide (L2), or glutarimide (L3) with Ni" salts at

pH 8.5 gives the complexes K2[Ni(Li),(MeOH),], K2[Ni(L2),], and [Ni(L3),(MeOH),].28g The properties of [Ni(RNH,),Im,] (RNH, = substituted primary amine, Im = succinimide or phthalimide) are consistent with a square-planar structure with the imido-ligand bonded through the N atom of the imide ring.' l o The octahedral complexes [Ni(H,NCN),]SO, and [Ni(H,NCN),](NO,), have been isolated, and in both the ligand appears to bond via the a m i n o - g r ~ u p . ~ The " 1,1,4-trimethylpiperaziniumcation (L+) forms '08 '09 'lo

'I1

R . C. Pettersen, J. Amer. Chem. Soc., 1971, 93, 5629. S. J. Cole, G . C. Curthoys. E. A. Magnusson, and J. N. Phillips, Znorg. Chem., 1972, 11, 1024. N. P. Slabbert and D. A. Thornton, J. Inorg. Nuclear Chem., 1971, 33, 2933. V. L. Goedken, L. M . Vallarino, and J. V. Quagliano, Inorg. Chem., 1971, 10, 2682.


295

the weak complexes [NiX,L] (X = C1, Br, or I) although, if the preparation is carried out in the prejence of traces of water, (LH)[Ni"X,] (X = C1 or Br) is formed.79 The NH,NMe, cation co-ordinates to nickel@) when ethanolic solutions of nickel salts are treated with the cation in a 1:2.5 mole ratio. The complexes [NiX,(H,NNMe,),] (X = C1 or Br) are formed, for which tetragonally distorted octahedral structures are proposed. When the solid chlorocomplex is heated to 145"C, (H,NNMe,),[NiCl,] is formed and this reaction is reported to be re~ersible.~ l 1 The complexes [Ni(oxalate)(N,H,)], (1.5-2)H,O, [Ni(oxalate)(N2H,),],0.5H,O, [(Ni(N,H,),)(oxalate)], Ni3(P04),,6N2H,,12.5H,O, and Ni3(P0,),,9N,H,,9H,0 have been r e p ~ r t e dl .2~The hydrazine derivative, (cyclohexyl),C=N-N=C(cyclohexyl), reacts with NiC1, in the presence of water to give the polymeric [ ~(cycIohe~yl)~C=-NNH2}NiC12].253The absorption of oxygen by [Ni(dmg),] has been studied.'13 0-Donor ligands. The structure of [Ni(H,O),](NO,), shows the cation to be nearly octahedral with a deformation towards an orthorhombic b i ~ y r a m i dl.4 ~ In an investigation of the hydrolysis of Ni2+ by NaCl, evidence was obtained for formation of Ni,(OH):+ and Ni,(OH), at 60°C, whereas Ni, {OH):', Ni2(OH)3+,andNi(OH)+ areformed at 25°.715The complexes [X(MeOH),]X, (X = ClO,, BF,, or NO,) have been isolated from the reactions of hydrated nickel salts with trimethyl orthoformate.* The thermal decomposition of K,[Ni(NO,),] follows the equation: +

K,[Ni(NO,),]

--t

and that of K,Pb[Ni(NO,),], K,Pb[Ni(NO,),]

3KN0,

+ KNO, + NiO + 2 N 0

the equation: + 2KN0,

+ PbO + NiO + 4 N 0

It was also found that the compound reported by Mellor and Berzelius as nickel plumbite is in fact tetragonal Pb0.551(NH,)2Ni,Vl,0,,,16H,0 has been reported.716The formate ion forms only the complex ion [Ni(O,CH)] + . 7 1 The i.r. spectra of [Ni(mal)],3H20 and H2[Ni(mal),],4H,O, (ma1 = maleate) suggest that the Ni-0 bond is less covalent in character than in oxalates or m a l o n a t e ~ The . ~ ~ thermal ~ decomposition of [Ni(glyc),],2NH3, [Ni(glyc)],2H,O, and [Ni(glyc),] (glyc = glycinate) has been studied,,,' and [Ni(benzilate),],2H20 has been prepared.256 The compounds NiA, (A = phenylglycollate or dinegative anion of 3-ketoglutai ic acid) have been rep0rted.8~. 86 Hydroxymethylenenorcamphorate (55) forms the octahedral polymeric complex Ni,L,,H20299 and the chiral d-3-trifluoroacetylcamphorato complex E. I. Krylov, M. G. Lyapilina, V. A. Sharov, and E. A. Nikonenko, Russ. J . Znorg. Chern., 1972, 17, 379; E. I. Krylov, V. A. Sharov, Y. N. Makurin, and E. A. Nikonenko, ibid.,p. 371. 7 1 3 0. S. Ksenzhek, L. S. Burachenko, I. 0.Volodina, F. E. Dinkevich, and G. G. Motyagina, Russ. J . Znorg. Chem., 1971, 16, 566. 7 1 4 F. Bigoli, A. Braibanti, A. Tiripicchio, and M. Tiripicchio-Camellini, Acta Cryst., 1971, B27, 1427. 7 1 5 H. Ohtaki and G. Biedermann, Bull. Chem. Soc. Japan, 1971, 44, 1822; K. A. Burkov, N . I . Zinevich, and L. S. Lilich, Russ. J . Znorg. Chem., 1971, 16, 927. 7 1 6 D . G. Wickham, J. Znorg. Nuclear Chem., 1972,34, 2673. 7 1 7 P. Bianco, M . Asso, and J. Haladjian, Bull. SOC.chim. France, 1971, 3943. 712


296

(153) has been prepared by an exchange reaction with the barium salt in organic solvent^.^

CF3

In Volume 1 the complex [MnBr(acac),] containing two unidentate enolic acac groups was reported (see Vol. 1, p.123). The same workers have now reported the structure of the similar nickel complex, [NiBr,(acacH),], prepared by the reaition of [Ni(acac),J and dry HBr in CH,Cl, in the presence of excess acetylacetone. The light-green compound is paramagnetic (peff= 3.39 BM) and has a strong v(C0) band at 1631 cm- A structural study shows the bromine atoms to be mutually tramv and the chelating ketonic acac groups to be non-planar (dihedral angle = 151 ') and in the boat conformation.719 The complex [Ni(acacH),(H,O),](C10,), has a unit cell containing two structurally different molecules which are both octahedral. One contains two planar ligands and the other two non-planar ligands. The non-planar ligands are consistent with being the keto-tautomer of (acacH),whereas it was not possible to assign a tautomeric structure to the planar form.720Anhydrous bisacetylacetonatonickel(I1) is known to be trimeric in the solid and in non-donor solvents, and now the first mixed trimeric complexes have been reported. When [Ni,Br[Ni,(acac),] is treated with dry HBr in petroleum ether-CH,Cl,, (acac),] is formed, and it is suggested that this contains five-co-ordinate nickel. Treatment of this compound with pyridine gives [Ni(acac),(py),] and [NiBr(acac)(py),]and it is considered that the latter is derived from the five-co-ordinatepart ofthe trimer. [Ni,Br,(acac),] and [Ni,Br,(acac),] w e r e a l s ~ i s o l a t e d . ~ ~ The reactions of Ni( P-dik), (P-dik = acac, bzacac, or dibenzoylmethanato) with py, piperidine. and quinoline,'22 and those of [Ni(acac),] with RNH, (R = up to C,, when saturated, up to C , , when unsaturated)423have been studied. The c.d. spectra of [Ni(acac),(aa)] (aa = Val. Ser, Arg, Orn, Pro, Asp, or Asn) have been interpreted in favour of equatorial acac l i g a n d ~ . ~ , ~ Thermodynamic functions for nickel(I1) complexes of acac, bzacac, anisoylacetone. and dibenzoylmethane have been reported.724as have polymerization constants for a range of nickel(II)-P-diketonates.;2j

'.

'I8

'I9

V. Schurig, Inorg. Chem., 1972, 11. 736. S. Koda, S. Ooi. H. Kuroya, K. Isobe, Y. Nakamura, and S. Kawaguchi, Chem. Comm., 1971, 1321.

720 721

i22

'23 724 725

K. Anzenhofer and T. G. Hewitt, 2. Krisr.. 1971, 134, 54. K. Isobe, Y . Nakamura. and S. Kawaguchi. Inorg. Nuclear Chem. Letters, 1971, 7, 927. A. G. Muftakhov, V. A. Alekseovskii, and L. M. Naumova, Rum. J . Inorg. Chem., 197I,16, I442. L. I . Katzin and E. Gulyas, Inorg. Chem., 1971, 10, 2411. B. Rao and H. B. Mathur, J . Inorg. Nuclear Chem., 1971, 33, 2919. A . Chopin-Guest and R. Hugel, J . Inorg. Nrtclear Chem., 1972,34, 2595.


297

When [(RSO,),Ni(OH,),] and bipy are heated to 50°C in water [Ni(bipy),](RSO,), is formed, and heating this in acetone gives [(RS(O)O),Ni(bipy),] and [{RS(O),),Ni(bipy),] (R = P - M ~ C , H , ) . ~ ~ ' When the yellow five-co-ordinate [Ni(Ph,EO),(ClO,),]. (E = P or As) complexes are heated to 200-3OO0C, blue isomers are formed which are tetrahedral, and the arsine-oxide complex also forms an unstable green isomer of unknown geometry.725"The complexes Ni(PH,PO),,(BF,), (n = 4 or 5) have been prepared. The tetrakis-complex is square-pyramidal and the pentakis-complex is octahedral, BF, co-ordination being postulated in both cases. and On heating green [Ni( OPPH,),BF,]BF,. yellow [Ni(OPPh,),BF,]BF, (X then blue [Ni(OPPh3),](BF4)2 are formed.92 Ni[PhP(O)(NMe,),],X, = C10, or BF,) and Ni[PhP(O)(NMe,),],Cl, have been reported.', Hexamethylphosphoramide (HMPA) and nonamethylimidodiphosphoramide (NIPA) form the octahedral complexes [Ni(HMPA),](ClO,), and [Ni(NIPA)3](C10,),.95 When [Ni{ S,P(OR),},] (R = Pri, Bui, or cyclohexyl) is dissolved in HMPA, five-co-ordinate paramagnetic species are formed. However, in trialkylphosphates the complexes formed are diamagnetic.726 The complexes Ni(NIPA)(SO,), Ni( OAc),O.S(NIPA), [Ni(NIPA),]I, [Ni(NIPA)J(NiI,) and Ni(NIPA)I, have also been reported.433* 7 2 7 The ligand (154) reacts with hydrated Ni(C10,), in acetone-2,2'-dimethoxypropane to 0

0

II II R-P-0-P-R I I

NMe, NMe, (154) R = Me, Et, or Pr'

give [NiL3](C10,),,432 and R,P(O) 0 * P(O)R, (R = Et or Ph) also forms complexes of $he type Ni[R,P(O) OP(0)R2]3(C10,)2.431Nickel(@ phenylphosphonate, phenyl-arsonate, and o-arsanilate have been prepared.98* 429 Crystalline NiBr2(dioxan),,4H,O has been isolated and spectral evidence indicates a trans-[NiBr,(H,O),] structure. Thermal decomposition of this complex gives rise to loss of both water and dioxan yielding, finally, NiBr,.82 LH (LH = nitroacetone, l-nitrobutan-2-one, 3,3-dimethyl-l-nitrobutan-2one, a-nitrbdeoxybenzoin, 2-nit rocyclohexane, or 3-nitrocamphor) forms the complexes [ML,B,] (B = H,O, n = 2 or 3; B = EtOH or py, n = 2) and and [ML,].425 The complexes [Ni(DMSO),(NCS),] have been rep~rted,~' the i.r. spectrum of [Ni(TMS0)6]2+ is very similar to that of the DMSO analogue." 1,4-Dithianemonosulphoxide (DTMSO) forms the complexes Ni(DTMSO),X, (n = 2, 3, or 6 ; X = C1, Br, I, NO,, or NCS). Complexes of tetramethyl- and tetraethyl-diothio-oxamide (L) have been investigated by the Job method, and [MLJX, (X = C10, or Fe"'C1,) were identified."

-

F. Mani, Inorg. Nuclear Chem. Letters, 1971, 7,447. J. R. Angus, G. M. Woltermann, and J. R. Wasson, Inorg. Nuclear Chem. Letters, 1971, 7, 837. M. W. G. D e Bolster and W. L. Groeneveld, Rec. Trav. chim., 1972, 91, 643.

725a

726 727

29 8

Inorgunic Chemistry of the Transition Elements

S- and Se-donor ligands. The preparation of [Ni(NH,),(CS,)] and [Ni(en),]CS, has been described. " The polarized electronic spectrum of [Ni( S,CPh),] contains more bands than predicted for mononuclear square-planar nickel(@, and a dimeric structure with the [Ni,S,] chromophore has been suggested.729 The structure of nickel trithioperoxybenzoate shows the co-ordination to be planar and the Ni-S bonds to short.',' The nickel xanthate [Ni(S,COEt),] reacts with [NiX,(PR,),] in ether to give [Ni-(S,COEt)X(PR,)] (R = Ph or cyciohexyl, X = C1, Br, or I),731 and some thioxanthate complexes have been found',, to lose CS2 spontaneously in solution to give dimeric mercaptidebridged complexes, i.e. 2[Ni(S,CSR),]

(R =

--t

2CS,

+ [Ni(SR)(S,CSR)],

Et, Bu', or PhCH,)

Two polymorphs of the 4,4'-bipyridyl adduct of nickel@) ethylxanthate have been isolated, one of which is capable of trapping a molecule of benzene, ether. acetone, chloroform, CCl,, or cyclopentadiene. The 1,lO-phen adduct also forms 1:1 clathrates with benzene, toluene, chloroform, and chlorobenzene.733 [Ni(S,COR),] and [Ni(S,PPri),] (NiL,) both form high-spin adducts with py. 4-Mepy, bipy. and 2.9-Me2-l.10-phen (B) formulated as NiL,B, and NiL2B.734[Ni(S,PEt2)2] reacts with PPh, to give paramagnetic [Nik,PEt,),PPh,], but not a 1:2 complex; the 1: 1 complex probably has a distorted square-pyramidal structure in the solid, but in solution dissociation occurs.' The five-co-ordinate morpholine adducts of [Ni(S,P(OR),} 2 ] (R = Et, Pr". Pr'. Bun. Bus, cyclohexyl, or PhCH,CH,) all have C,o symmetry,-3 6 Bis-(00'-di-isopropy1dithiophosphato)nickelreacts with py, 3-Meor 4-Me-py (L) to form [Ni{S2P(OPr'),),L,].737 2-Mepy and quinoline adducts have also been studied.738[((EtO),PSe,),Ni] is low-spin and forms an octahedral bis-pyridine adduct. '00 Me,AsS, forms the compound Ni(S,AsMe,),, which is square-planar.' O 2 A polarographic study of [Ni(sacsac),] in acetone shows the complex to have a well-defined capacity to accept electrons in a reversible stepwise manner, and the magnitude of the potentials and their reversibility suggests that 'I8 729

730 731 732

733 734

735 '36

737

738

V . M . Schul'man, S. V. Larionov, L. A. Podol'skaya, and V. E. Fedorov, Russ. J . Inorg. Chem., 1971, 16, 1024. C. Furlani, 0. Piovesana, and A. A. G. Tomlinson, J.C.S. Dalton, 1972, 212. M. Bonarnico, G. Dessy, V . Fares, and L. Scaramuzza, J . Chem. SOC.( A ) , 1971, 3191. C. Blegean and J. L. Chenot, J . Inorg. Nuclear Chem., 1971, 33, 3166. J. M . Andrews, D . Coucouvanis, and J. P. Fackler, Inorg. Chem., 1972, 11,493. A. G . Kruger and G . Winter, Austral. J . Chem., 1971, 24, 1353. D. R. Dakternieks and D . P. Graddon, Austral. J . Chem., 1971, 24, 2509. N. Yoon. M . J. Incorvia. and J . I . Zink, J . C . S . Chem. Comm., 1972, 499. J. R. Angus, G. M.Wolterrnann, W. R. Vincent, and J. R. Wasson, J. Inorg. Nuclear Chem., 1971, 33. 3041. H. E. Francis, G. L. Tincher, W. F. Wagner, J. R. Wasson, and G. M. Wolterrnann, Inorg. Chem., 1971. 10, 2620. J. R. Angus, G. M. Woltermann, and J . R. Wasson, J . Inorg. Nuclear Chem., 1971,33, 3937.

299


isolation of low-valency nickel-sacsac complexes should be possible.43 The new complexes (155) have been isolated.739 [Ni(S-S),] [S-S = S,C,(CF,)J reacts with a range of 1,l-dithiolates to R'

R2

= R2 = Me, Bu' R' = Me,R* = Ph R' = Me,R2 = C,H,, R 1 = Ph, R2 = CF,

(155) R'

give centrosymmetric mixed ligand dimers of nickel. Kinetic, spectral, and conductiometric results indicate a rapid reversible formation of a polarized 1: 1 intermediate between the nickel dithiete and the metal bis(dithiolate), except for [Cu(S,CNR,),] complexes, which instantaneously form 1:1 salts. At room temperature a21 the systems investigated ultimately yield the mixed ligand dimer as the sole nickel-containing product. Xanthates react more slowly than dithiocarbamates and nickel compounds faster than those of copper or zinc. The structure of [Ni(S,C,(CF3),](S,CNEt,)] has been determined and the nickel atoms have square-pyramidal co-ordination (156).740 The series of complexes. [Xis: Si]-[S: = S,C,(CN),, Sg = S2CNBui] have

been prepared and volt ammetry shows E , values intermediate between those of the complexes with unmixed l i g a n d ~ . Similar ~~' results have been obtained for [Ni { S C (CN) 1(S C NC N)] - , [Ni { S C (CN) ](S COEt )] - , and some related dithiocarbamate complexes.742 The dithiolate complex [Ni{ S,C,(CN),} (o-C,H,(AsMe,),)] has been r e p ~ r t e d . ~

,, ,

739 740

741 742

,, , ,

C. Blejean, Inorg. Nuclear Chem. Lelfers, 1971, 7 , 1011. A. Hermann and R. M. Wing, Inorg. Chem., 1972,11, 1415. J. G. M. van der Linden and H. G. J. van der Roer, Inorg.,Chim. Acta, 1971, 5,254. J. G. M . van der Linden, J. Inorg. Nuclear Chem., 1972,34, 1645.


300

[(n-Cp)Ni(PBu;)Cl] reacts with NaS0,Ph or NaSO;C,H,Me in aqueous With solution at room temperature to yield [(K-C~)N~(PBU~)(S(O),R)]. sodium benzenethiolate or sodium 3-toluenethiolate under similar conditions [(n-Cp)Ni(PBu”,SR] is formed and [(n-Cp)Ni(PBu:)SH] reacts with phenylacetylene to give [(n-Cp)Ni(PBu”,SC(Ph)=CH2] . 7 4 3 The thiolates [(n-Cp)Ni(PBu;)SR] (R = Et or PhCH,) and [(K-Cp)Ni(PBu:)S(CH2)nSNi(PBu:)(n-Cp)] ( n = 2, 4, or 6 ) undergo insertion reactions with CS, to form the trithiocarbonate complexes [(n-Cp)Ni(PBu’,)S*C(S)*SR]and ( 157).744

Bu:P

/

Ni

\

S- C-S

II

(CH,), S-C-S

II

/

Ni

\

PBu:

S S (157)n = 2,4,or6

1,5-Bis-(2-mercaptoethylthio)pentane forms a polymeric nickel(rr) complex. Spectral, magnetic, and thermal decomposition studies have been reported for the c ~ m p o u n d . ~The cyclic dithioethers, 1,4-dithiacycloheptane (dtch) and 1,5-dithiacyclo-octane (dtco) form the square-planar complexes [NiLJX, (L = dtch or dtco: X = C10, or BF,) and the octahedral polymer [Ni(dtco),Cl,]: however, the complex [Ni(dtch),CI,] could not be isolated. The complexes [Ni,(dtco),Br,] and [Ni,(dtch),Br,] were also obtained, and the former contains two tetrahedral nickel atoms with one bridging and two unidentate dithioether ligands, whereas the latter contains trigonal-bipyramidal nickel with one bridging and two bidentate ligands or may possibly be polymeric. Tetrahedral [Ni(dt co)IJ, octahedral [Ni(dtch),I ,I, and [Ni(dt co),T 2], which is either planar or low-spin octahedral, were also obtained.745The reaction of [Ni(sst),] (158) with MeLi in THF gives [Ni(H,Messt),12- which undergoes controlled oxidation to [Ni(H,Messt),] - and exhaustive oxidation to [Ni( M e ~ s t ) , ] .The ~ ~ ~structure of (158) has been reported: the co-ordination is planar and it was iound L! the C--C bond associated with the chelate ring is longer than the others (1.448 A, c j 1.378-1401 A). This is consistent with the previously reported chemical properties of the compound and its lack of dithiolen character.747The structure of [Ni(S,CNHMe),] has also been reported.748

(158) 743 744 745

746 747

748

M . Sato, F. Sato, N. Takemoto, and K. lida, J . Organomeiallic Chem., 1972, 34, 205. F. Sato, K. Iida, and M . Sato, J . Organometallic Chem., 1972, 39, 197. W. K. Musker and N. L. Hill, Inorg. Chem., 1972, 11, 710. T. Herskovitz, C. E. Forbes, and R. H. Holm, Znorg. Chem., 1972, 11, 1318. G. P. Khare, A. J. Schultz, and R. Eisenberg, J . Amer. G e m . Soc., 1971, 93. 3597. P. W. G. Newman and A. H. White, J.C.S. Dalton, 1972, 1460.

30 1


Ethylenethiourea (etu) and tetramethylthiourea (tmtu) form the complcxes NiL,X, ( L = etu or tmtu; X = C10, or NO, : n = 2 or 4). [Ni(tmtu),(NO,),] exists in two forms, orange and green. The former has a highly distorted octahedral structure, whereas the latter, while still octahedral, shows much less 1-phenyl t hiourea, - 1,l -dimethyld i ~ t o r t i o n3 8. ~ 3-Diphenylphosphinothioylthiourea, and -1,l-diethylthiourea all behave as bidentate ligands towards nickel(i1) forming square-planar complexes.439 NiL, complexes rL = R'R'N-NH-CS,, (R' = H, R2 = Me: R' = R2 = Me; R' = R2 = Ph; R' = Me, R2 = Ph), NH,NRCS, (R = H, Me, Et, Pr", or Bun), and MeNH. NMe. CS,] have been prepared. Most are spin-paired, except when L = NH,NHCS, and Me,NNHCS,, and it was found that the substitution exerts a strong effect on whether the ligand is SS or NS bonded.749 N.m.r. results indicate that the square-planar complexes formed between Ni" and L-cysteine or its methyl ester appear to have some (d-d)n character to the Ni-S bonds.750 P- and As-donor ligands. The diamagnetic complexes [NiL,X] (X = C1, Br, I, or NCS), NiL,X, (X = Br or I), and [NiL,X]+ (X = Cl,-Br, I, or NCS) (L = PHEt,) have been prepared. The stability of the five-co-ordinate complexes in solution depends on the solvent and the presence of free ligand, and spectral data on the previously reported [NiL,X,] complexes suggest they are The better formulated as [NiL4X]X (X = C1 or Br) in the solid electronic spectra of the low-spin five-co-ordinate complexes, [Ni(PMe,),X,] ( X = NCS or NO,) indicate that the thiocyanate is trigonal-bipyramidal and that the nitro-compound is square-pyramidal in the solid state. In solution the nitro-compound exists in both square-pyramidal and trigonal-bipyramidal forms.752 [NiL,X,] [X = C1, Br, I, or NCS; L = PPh,(cyclohexyl), PPh(cyclohexyl),, P(cyclohexyl),] complexes have been prepared. The thiocyanate complexes are trans-planar and the halogeno-complexes show a tetrahedral + planar equilibrium in solution. The amount of paramagnetic tetrahedral form follows the order PPh, > PPh,cy > PPh(cy), > P(cy), for a given X and I > Br > Cl for a given phosphine, the tetrahedral form being favoured in polar solvents. Both structural isomers of some complexes were isolated in the solid state.7s3The complexes [NiBr,(P(OR),},] (R = hexyl, octyl, nonyl, Bu', or iso-octyl) have been isolated, and it was found that an increase in the chain length of R above C, has no effect on the ligand-field strength of the phosphite~.~'~ (X = C1, The complexes [Ni(Me,PPMe,)X,] and Ni(Me,PPMe,),X, Br, or I) have been isolated.2611,2-Bis(diethylphosphino)ethane(tep) forms the complexes [Ni(tep),X]BPh, (X = C1, Br, I, or NCS) and [Ni(tep)X,] (X = C1, +

749 750

751

lS2 753 754

C. Battistoni, G. Mattogno, A. Monaci, and F. Tarli, J . Znorg. Nuclear Chem., 1971, 33, 3815. D. F. S. Natusch and L. J. Porter, J. Chem. SOC.( A ) , 1971,2527. P. Rig0 and M. Bressan, Inorg. Chern., 1972, 11, 1314. A. Merle, M. Dartiguanave, and M. X. Dartiguanave, Bull. SOC.chim. France, 1972, 87. P. J. Stone and Z. Dori, Znorg. Chim. Acta, 1971, 5, 434. G. D. Ginsburg, E. A. Zgadzai, N. S. Kolyubakina, P. A. Kirpichnikev, N. A. Mukmeneva, V. A. Pishchulina, and A. D. Troitskaya, Russ. J . Znorg. Chem., 1971, 16, 1022.


302

Br, I, NCS, or CN), which are five-co-ordinate and four-co-ordinate, respectively. The former have been assigned a squafe-pyramidal geometry on the basis of electronic spectral data and a structure determination on the iodo-complex [Ni(tep),T]I. and the latter are square planar. The square-planar complexes react with Me,PhP to form [Ni(tep)(PMe2Ph)X2].755 cis-[ru'i(dpe)X,] (X = C1, Br, or 1) have been found always to display lower Ni-X and higher Ni-P stretching frequencies than trans-(Ni(PEt3)2X,].756 Conclusive evidence has now been presented for the existence of [Ni(dpe),X]' (X = Cl, Br, or I) in equilibrium with cis-planar [Ni(dpe)X,]. Calorimetric studies on [Ni(dpe),Br] indicate it has stability comparable to that of its cobalt(r1) analogue.757The reaction of [(x-Cp)Ni(PPh,(CH,)nPPh2}Cl](n = 1, 2, 3, or 4)with aqueous NaCN gives the complexes (159) and ( 160).'758 The structure of the 1-benzyl-A3+

(TI-

I

CP)

Ni Ph ,P(CH,) PPhf

\CN (159)

(x-Cp)

(Jr-Cp)

\

Ni -PPh,(CH,),

Ph2P- Ni

/

\CN

NC' (160) n = 2.3. or 4

phospholen complex (161)shows the co-ordination to be tetrahedrally distorted square-planar, the phosphine ligand showing a high tra~s-influence.~~ Ph

\

H-C

i

Ph (161)

(Ph,PCH,CH,),PPh

(Pf.Pf.Pf) forms the square-planar complex whereas Ph, P (CH*), PPh (CH, ),PPh (.CH j,PP h, (Pf.Pf.Pf.Pf). forms [Ni(Pf.Pf.Pf.Pf)]Cl,, which is also square-planar, and (Ph,PCH,CH,)3P [P(Pf),] forms the five-co-ordinate cation [P(Pi),NiCI] +., (Ph,PCH,CH,),P(CH ,),P(CH,CH ,PPh, j2 [P2(PQ4] reacts with NiCl, to form [Nip,( Pf),]Cl, in which the ligand is tetradentate.27

[Ni(Pf.Pf.Pf)Cl] PF, ,'

'55 '56

757 758

'''

,

E. C. Alyea and D. W . Meek, Indrg. Chem., 1972. 11, 1029. C. Udovich, J. Takemoto, and K. Nakamoto, J . Coord. Chem., 1971, I, 89. R . Morassi and A. Dei, Inorg. Chim. Acta, 1972,6, 314. F. Sato, T. Uemura, and M . Sato, J . Organometallic Chem., 1972, 39, C25. A . T. McPhail, R. C. Komson, J. F. Engel, and L. D. Quin, J.C.S. Dalton, 1972, 874.

Elemeiits of the First Transitional Period

303

The structure of [Ni(ttas)X,] [ttas = bis-(0-dimethylarsinopheny1)methylarsine, X = C1, Br, I, or SCN] is very sensitive to the nature of X and the solvent. Five-co-ordinate monomers are favoured in polar solvents, whereas hydroxylic solvents favour disproportionation to [Ni(ttas),]'+ and either NIX:- or its solvolysis products. The co-ordination geometry of [Ni(ttas),Y ,] (Y = ClO,, NO,, or I) is not certain.760 Mixed donor ligandg. The structures of [Ni(pi~olate),],4H,O~~~ and [Ni(py2,6-C0,),],3H,0762 have been determined and are shown in (162) and (163)

=O

(162)

(163)

respectively. 2-Pyridone (L) forms the complexes [NiL,(NO,),] and [NIL,(NO,),],nH,O '' and 2,3-di-(2'-pyridine N-oxide) quinoxaline (L.') forms the octahedral complexes [Ni, LiCl,] ,4H, 0, [Ni, L i C1 ,],4H 0, [NiLt Br ,I ,H,O, and [NiL:12],H20.453 The reaction of Ni(H,O),(ClO,), with 2,6diacetylpyridinedioxime (dapdH,) in acetone yields [Ni(dapdH,),](CIO,), which, on reduction with sodium in methanol, forms N a , [ N i ( d a ~ d ) , ] . ~ ~ ~ The structure of cis,cis-1,3,5-tris(pyridine-2-aldimino)cyclohexanenickel@) perchlorate has been reported and shows significant distortion from trigonal prismatic geometry (average angle of twist from trigonal prismatic = 32 0).764 Ni" complexes of 1,1O-phenanthroline-2-carboxamidehave been isolated.262 [Ni(salox),L,,] (L = 3,4:lutidine7 n = 2; L = 3,5-lutidine, n = 3) have been prepared.765The reaction of acetone and [Ni(en),12+ gives (164), which is different from the higher temperature reaction SbCl,, SbBr,, and SbC1, react with [Ni(salen),] to give adducts in which the planarity is maintained. To clarify the question of the local symmetry about the acceptor metal in such adducts, the substitution products [Ni(salen),M(CO),] (M = Mo or W) and [Ni(salen),Mn(CO),X], and [Ni(aben),Mn(CO),X] (aben = "'-ethylenebis-o-aminobenzylideneiminate, X = Cl or Br) were prepared and the C-0

,

76Q 761 762

763 764 765

766

R. G. Cunninghame, R. S. Nyholm, and M. L. Tobe, J.C.S. Dalton, 1972,229. H. Loiseleur, Acta Cryst., 1972, B28, 816. H. Gaw, W. R. Robinson, and R. A. Walton, Znorg. Nuclear Chem. Letters, 1971, 7, 695; A. Chiesi-Villa, C. Guastini, A. Musatti, and M. Nardelli, Gazzetta, 1972, 102, 226. E. I. Baucon and R. S. Drago, J . Amer. Chem. Soc., 1971,93, 6469. E. B. Fleischer, A. E. Gebala, and D. R. Swift, Chem. Comm., 1971, 1280. F. Maggio and V. Romano, J . Inorg. Nuclear Chem., 1971,33, 3993. N. F. Curtis, J.C.S. Dalton, 1972, 1357.


304

NH

N

NH

N

stretching frequencies used to assign the s t r u c t ~ r e s . 'Ni(NO,), ~~ reacts with [Ni(R-salen),] (R = Et or Pr') to give trinuclear complexes (165) which contain two pseudo- tetrahedral and one octahedral nickel atoms.768

NO3

The 1 :1 complex formed between 1,3,5-TNT and [Ni(N-But-salen),] is isomorphous with the cobalt analogue.460 The structure of [Ni(N-n-septylsalen),] has been reported.769 [Ni(N-Pr-salen),] complexes have been Ni" complexes of the ligands (166) and (167) appear to be pseudosquare-planar (perf= 1.2 BM), the anomalous magnetic behaviour arising either from a singlet-triplet equilibrium or the coexistence of readily interconvertible high- and low-spin complexes in the solid The structure of NiL,6H20 [L = (168)l shows the ligand to be ~ e x i d e n t a t e . ~ ~ '

C=N(CH, ),NH (cH,),N=c

x

X (166)X

=

H, 5-Br, 3-Me0,5-Me, or 3-Pr'

M. D. Hobday and T. D. Smith. J . Chem. SOC.( A ) , 1971, 3424. J. 0. Miners, E. Sinn, R . B. Coles, and C. M . Harris, J.C.S. Dalton, 1972, 1149. 7 6 9 R. Graziani and E. Forselli, Inorg. Nuclear Chem. Letters, 1972, 8, 775. "O J. Csaszar and I. Barta, Acta. Chim. Acad. Sci. Hung., 1972, 71, 269. 7 7 0 a W . M. Coleman and L. T. Taylor, Inorg. Chem., 1971, 10, 2195. 7 7 1 P. D. Cradwick, M . E. Cradwick, G . G . Dodson, D. Hall, and T. N. Waters, Acta Cryst., 1972, B28, 45. 767

768

305


CH=N-CH-CH2-

I

NH-CHz-CH-N=HC

I

Me

Me (167)

CH=N(CH,) ,NH(CH,),NH(CH,),N--LH

CLH

HO (168)

It has previously been shown that the oxazines (169) can isomerize by ringopening to the Schiff bases (170). The reactions of the oxazines with Ni", Co", and Cu" have now been examined in the hope of yielding chelates of the Schiff bases. However, the products were not the expected ones; in the case of nickel, two kinds of chelate were obtained. Those formed in the absence of air were (171), in which proton migration from the original ligand had occurred, and, in the presence of air, (172) was formed in which dehydration had taken place on the original oxazine. The Con and Cu" chelates are structurally analogous to the nickel

x q Q p @ - x (169)

R1 = Me,R2 = Me,X = H R'R2 = (CH,),,X = H R'R2 = (CH,),, X = C1

772

W

R' = R2 = Me,X R1R2= (CH,),,X

H. Kantomi and I. Murase, Inorg. Chem., 1972, 11, 1356.

=

CMe,

= CMe,

306


Ni" complexes of linear potentially quinquedentate ligands derived from a variety of substituted salicylaldehydes and bis-(2,2'-aminoethyl)sulphidehave been prepared. The five-co-ordinate complexes show anomalous magnetic behaviour which may arise from singlet-triplet equilibrium or the coexistence of high- and low-spin complexes in the solid.773The neutral bidentate ligand (bape) derived from acetophenone and en forms tetrahedral Ni(bape)Cl, and [Ni(bape)(acac)(H,0,](C104) and planar [Ni(bapeXaca~)]ClO,.~ 74 NIL [L = (173)] complexes have been prepared and, unlike the salicyladimine analogues, the complexes derived from long-chain amines are soluble in non-donor solvents, in which they exist as square-planar monomers. In the solid, some of the compounds (n = 5-12) contain both octahedral and square-planar Ni", usually in the ratio 1 :2, and trimeric structures are proposed to account for this.775The reaction between R ' R 2 C 0 and benzil monohydrazone in the

(173) n = 2-12

presence of NiU gives (174).776The complex (175) has been is~lated.''~The reaction of enH, and acacH in O.1M-NaHCO, solution for 18 h at 5"C, followed by the addition of NiC1,.6H2O in water and further reaction for 24 h at 25 'C gives ethylenedinitrilobis-(2-pent-3-en-4-olato)nickel(11).~~~ The reThe action of [Ni(acacen),] with NO or NO; gives isonitr~so-derivatives.~~~ reaction of ethylenediamine or CCC'C'-tetramethylethylenediamine with glyoxylate gives 1 : i adducts that are considerably more stable than Schiff '?'

774 775

776

?18

W. M . Coleman and L. T. Taylor, J . Inorg. Nuclear Chem., 1971,33, 3049. K. Dey, R. L. De, S. K. Sen, and K. K. Chatterjee, 2. anorg. Chem., 1972,389,215. G. M. Mockler, G. W. Chaffey, E. Sinn, and H . Wong, Inorg. Chem., 1972, 11, 1308. C . M. Kerwin and G. A. Melson, Inorg. Chem., 1972, 11, 726. J. D. Wilson and J. S. Wager, Syn. Znorg. Metalorg. Chem., 1971, 1, 187. K. S. Bose and C . C. Patel, J . Inorg. Nuclear Chem., 1971, 33, 2947.

Elements of the First Transitional Period Ph

307

Ph

mPh

Ph (174) R'

Me, R2 = Me, Et, Pr", Bun, 0 1 Ph R' = R2 = Et =

bases. These adducts form complexes with Ni" which are, however, considerably less stable than Schiff-base a d d u ~ t s . ~ ~ ~ N-Hydroxyethylenediamine (hen) forms the complexes Ni(hen),X, (X = C1 or Br), [Ni(hen),X,] (X = NO, or ClO,), and [Ni(hen)X,],H,O (X = C1 or Br). The co-ordinated ligand reacts readily with acetone via condensation with the primary amino-group, and condensation of acetone with hen in the absence of metal ions also occurs. However, attempts to prepare complexes of the condensed product by subsequent addition of a metal salt gave only complexes of hen.4s0 The structure of Ni[N(CH,CH,OH),],(NO,), has been reported, the ligands being terdentate.780 1,5-Diazacyclo-octaneNN'-diacetatonickel(I1) dihydrate contains the ligand in its quadridentate form and a co-ordinated water molecule giving square-pyramidal co-ordination. The unique aspect of this structure is the sterically forced five-co-ordination, with a methylene hydrogen atom blocking the sixth position.781 The preparation of (176) has been reported and the unusual stability of the LNi; unit is illustrated by the formation of [LNi,(NH,)],DMF from a reaction where the only source of NH, is NH; and the strongest base present is acetate. The structure of [LNi,(OEt)(DMF),] has been r e p ~ r t e d . " ~ 2-Methylbenzoxazole (mbo) and 2-methylbenzoselenazole (mbse) form the complexes [Ni(mbo)(OAc),],[Ni(mbo),X,] (X = C1, SCN, or NO,), [Ni(mbse)Cl,], and [Ni(mbse),X,] (X = SCN, NO,, Br, or I).783 2-Hydroxymethylbenzothiazole (hbmt)and 2-acetonylbenzothiazole (acbt)form thecompounds [Ni(hbmt),X,] 779

"O 781

'82

783

A. Hilton and D. L. Leussing, J . Amer. Chem. Soc., 1971,93, 6831. K. Nielsen, R. Hazell, and S. E. Rasmussen, Acta Chem. Scand., 1972, 25, 889. D. 0.Nielson, M. L. Larsen, R. D. Willett, and J. I. Legg, J . Amer. Chem. Soc., 1971, 93, 5079. B. F. Hoskins, R. Robson, and H. Schaap, Inorg. Nuclear Chem. Letters, 1972, 8, 21. M. V. Artemenko, E. A. Christyakova, P. A. Supruenko, and G. I. Kal'naya, R u n . J. Inorg. Chem., 1972,17, 373.


308

II

II

N

/N

Me (176) X = MeO, EtO, MeOC,H,O,

N,, NH,. C,H,NH, PhNH. NH, OH, OCN, or C,H,N,

(X = SCN, C1, or Br), (hbmt),NiX,(X = C1 or Br), Ni(hbmt),(NO,),, The pseudo[Ni(hbmt)I,], and [Ni(acbt),X,] (X = NO,, SCN, or octahedral complexes [Ni(dape)(SCN),] and [Ni(dape),X,] (X = Br, I, NO,, CIO,, SCN, or SeCN) have been isolated. 1.r. evidence suggests co-ordination of the ether oxygen atom as well as of the primary amino-groups in dape [3,3'-bis(aminopropyI)ether] giving rise to fuc-configuration and a strong tetragonal distortion. In DMF, the solvent displaces the ether 0 atoms.785 A new route to the complexes (177) has been reported by the reaction of isonitroso-acacH and Ni(OAc), in the presence of NH, and an alkylamine in 50 % aqueous Both [Ni(acetaldioxime),C12] and [Ni(acetamide),(H20),] have been shown to be six-co-ordinate in the solid The first report of neutral monohalogeno-terdentate ligand nickel(r1) complexes has 0

0

R (177) R = Me, Et, C,H,OH, Pr", Bu", n-C,H,

appeared. Thus NiXL (X = el, Br, or NCS; L = an N-P-R',R2-aminoethyl-2acetiminodimedonate or -2-formyldimedonate) complexes have been isolated and factors favouring their formation discussed.788 2-Acetamidothiazole '84

'*' 786 787 788

M. V. Artemenko, E. A. Christyakova, P. A. Supruenko, and G. I. Kal'naya, Rum. J . Inorg. Chem., 1971, 16, 1305. A. G. King and L. T. Taylor, J . Inorg. Nuclear Chem., 1971,33,3057. K. S. Bose and C. C. Patel, Syn. Inorg. Metallorg. Chem., 1972, 2,41. M. E. Stone, B. E. Robertson, and E. Stanley, J . Chem. Soc. ( A ) , 1971, 3632. T. I . Benzer, L. Dann, C. R. Schwitzgebei, M. D. Tamburro, and E. P. Dudek, Inorg. Chem., 1971, 10, 2204.


309

(acam) and 2-acetamidobenzothiazole (acamb) form the complexes [Ni(acamb),X,] (X = CI, Br, or I),[Ni(acamb),I,],2H20, and [Ni(acam),X,],H,O (X = CI or Br) in which the ligands are co-ordinated via the carbonyl group and the thiazole N atom. Ni(acam),(NO,), has also been prepared which has carbonyl, amide N, and thiazole N co-ordination. This complex is of interest as an example of co-ordination via a non-deprotonated amide N atom.789 Ni" forms square-planar bis-complexes with the amidate anions of L-Val, ~ ~ structure ' of bis(G1y)-bis(imidazole)nickel(n) has been L-Phe, and L - P ~ o .The reported and the configuration around the metal atom is cis-O(carboxyl), cis-N(amine), ci~-N(imidazole).~~' Tetra- and penta-peptide complexes of nickel@) consume oxygen in neutral solutions as the metal ion catalyses peptide oxidation to give a number of products, including amides of aminoacids and peptides, 0x0-acids, and C0,.792 The complexes of acetylhydrazine (L), [NiL,]Cl2,1.5H2O and [NiLJBr,, have been prepared and their i.r. spectra studied.lo3 Cationic complexes of N-acylhydrazines have been prepared with the ligand in its keto-f~rm.,~ Nickel(x1) N-hydroxyurea complexes have been reported,' O4 as has a complex of 8-amino-7-hydroxy-4-methylcoumarin.322 The complexes (178) are formed by treating the appropriate diazonium salts with substituted hydroxylamines and then adding Ni(OAc), to a solution of the product. When X = OMe, OEt, or SMe the complexes have distorted octahedral co-ordination in both solid and solution but, when X = halogen, the solids are diamagnetic and partial paramagnetism in solution indicates a planar + pseudo-octahedral equili1-(2'-Pyridyl)-2-azonaphtholnickel(rr)complexes have been rebrium.,', por ted.45

,

(178) R = Me, Et, or Pr" X = F, C1, Br, I, OMe, OEt, or SMe

The complex [L,NiCl,] (L = 2-pyridyldiphenylphosphine)is tetrahedral,465 and the square-pyramidal complexes [NiLXlY [L = Ph,P(CH,),NMe(CH,),NMe(CH,),PPh,; X = halogen or pseudohalogen; Y = Br, I, ClO,, BPh,, or PF,] have been isolated.466The structure of the complex X = Y = Br 789

790 791 '92

M. N. Hughes and K. J. Rutt, Znorg. Nuclear Chem. Letters, 1971, 7 , 1049; J.C.S. Dalton, 1972, 1311. T. Komorita, J. Hidaka, and Y. Shimura, Bull. Chem. SOC.Japan, 1971,44, 3353. H. C. Freeman and J. M. Guss, Acta Cryst., 1972, B28,2090. E. B. Paniago, D. C. Weatherburn, and D. W. Margerum, Chem. Comm., 1971, 1427.


310

has been determined and the axial Ni-Br bond length is very long (2.807 A). This has been rationalized in terms of an MO picture in which the effect of the elongation of the bond is to decrease the antibonding character of the electrons in the MO, which is essentially d z z . 4 6 6 The complex rNi(N,P)Br]BPh, [N,P = bis-(2-ethylaminoethyl)(2-diphenylphosphinoethyl)amine]in its lowspin form has the chromophore [NiN,PBr] in the solid state. However, in CDCI,. both this complex and its chloro analogue show a temperaturedependent equilibrium between trigonal-bipyramidal (high-spin) and planar (low-spin) structures. The corresponding iodo-complex is formed only in its low-spin ~ t a t e . ’ ”The ~ ligand Ph,P(CH,),N=CMeCMe=N(CH,),PPh, (L) forms the planar four-co-ordinate complex [NiL](ClO,), and the squarepyramidal complexes [NiLX]ClO,,O.SEtOH (X = C1, Br, or I) and [NILXIC104,0.4BuOH (X = C1 or Br).794 The five-co-ordinate complexes [Ni(CDPP)X]X (CDPP = 8-quinoldiphenylphosphine;X = C1 or Br) have also been r e p ~ r t e d . ~o-Dimethyl~“ and o-diphenylarsinoaniline and 1 -amino-2(dipheny1arsino)ethane form the octahedral complexes NiL,X, (X = halogen, NCS, or NO,) and the planar complex [NiL2](C104)2.795 The product of the reaction between ,bis(S-aminodithionitrito)nickel(Ir), NH,, HCHO, and MeOH has the structure (179).796 Complexes of 2,1,3benzothi adiazole, 2,1,3-ben~oselenadiazole,~ i ~ o t h i a z o l e ,2-methylbenzo~~

//s -N-

‘

CH ,-N-CH

I I S-N’

S- ~i -N,

/

,OMe

,CH,

‘s

(179)

thia~ole,’~’and t h i ~ p h e n a l d o x i m ehave ~ ~ ~ been reported. a-N-Methy1-Smethyl-~-N-(2-pyridyl)methylenedithiocarbazateand its 6-methyl-2-pyridyl analogue form the complexes [NiL,](CIO,), and [NiLX,] (X = C1, Br, I, or forms the squareNCS),’ 267 and S-methyl-N-isopropylidenedithiocarbazate planar complex NiL, . 3 2 6 Anthralinic aldehyde selenosemicarbazone forms the octahedral complexes [NiL,]X, (X = C1 or NO,) and the square-planar complex Ni(L-H)NH3,3H,O which all contain the ligand in its terdentate form.600 Complexes of (180: R = substituted Ph) have been isolated and it has been shown by dipole-moment studies that introduction of sulphur instead of oxygen co-ordination gives significant changes in polarity. The complexes also show a square-planar F+tetrahedral . equilibrium in The 793 794 795

’96 797

798

I. Bertini, P. Dapporto, G . Fallani, and L. Sacconi, Inorg. Chem., 1971, 10, 1703. T. D. DuBois, Znorg. Chem., 1972, 11, 718. B. Chiswell, R. A. Plowman and K. Verrall, Inorg. Chim. Actu, 1972,6, 113. U. Thewalt and C. E. Bugg, Chem. Ber.. 1972,105, 1614. M. V. Arternenko, E. A. Christyakova. P. A. Supruenko, and G. I. Kal’yana, Russ. J . Inorg. Chem., 1971, 16, 574. L. S . Minkina, V. P. Kurbatov, 0. A. Osipov, V. I. Minkin. and L. E. Nivorozhkin, Russ. J . Inorg. Chem.. 1971, 16, 571.


31 1

complex [Ni(mdtc),] (mdtc = morpholine-4-carbodithioate) has been prepared328and the structure of Ni(thioglycinate), r e p ~ r t e d . ~ ” The Schiff bases TIB-R (180), TIB-en (181), TIBDPT and TIBMeDPT (182) form the complexes Ni(T1B-R-H), and Ni(L-2H) [L = (181) or (182)l. They The thiocarbazides (HL) form show a variety of co-ordination the complexes [Ni(HL),NO,]NO, (HL = RCONHNHCSNHNH,; R = Ph, Me, or nicotinoyl, RCO = 2-C1-benzoyl or 2-HO-benzoyl).All are octahedral with the ligand bonding via the S atom and the primary amino N; the nitrato-

QcH=NR ’SH ( 1 80) R

\ /S

O

=

Me, Et, Pri, Bus, But, or substituted-Ph

H

H

\S /O

CH2(CH,)2-NR(CH2)2CH,

I

,CH=N

I

N=CY

(182) R = H, TIBDPT R = Me,TIBMeDPT

group is also bidentate.800 Nickel complexes of acetylacetonebisthiosemicarbazone,801 o-(N-dimethylamino)benzaldehydethiosemicarbazone,8o2and pyruvamide t h i o s e m i c a r b a z ~ n ehave ~ ~ ~ also been reported. Two types of dithiocarbazic acid [R1R2NNR3CSSMe(R’ = R2 = R3 = H; R1 = R2 = H, R3 = Me; R1 = R2 = Me, R3 = H; R1 = R2 = Ph, R 3 = H ; R1 = P h , R2 = R3 = H)] complexes of nickel have been obtained; viz. high-spin 799

J. R. Ruble and K. Seff, Acta Cryst., 1972, B28, 1272.

’’’ N. K. Dutt and N. C. Chakder, Inorg. Chim. Acta, 1971, 5, 188. A. M. Romanov,A. V. Ablov, and F. G. Shepel, Russ. J . Znorg. Chem., 1971, 16, 1533. A. V. Ablov, N . V. Gerbeleu, and M. V. Shopron, Russ.J . Inorg. Chem., 1971, 16, 932. A. V. Ablov, N. I. Belichuk, and L. A. Nezhel’skaya, Russ. J . Inorg. Chem., 1972, 17,226.


312

[NiX,(R1R2NNR3CSSMe),] (X = halogen) and low-spin [Ni(R'R2NNCSSM e),] .' Hydrazinedithiocarboxylic acid, its methyl ester, and their N-isopropylidine derivatives form a range of nickel(@ complexes. The carboxylate acts as monobasic ligand giving bis-neutral and tris-anionic complexes; the ester acts as a monobasic bidentate ligand through deprotonation of the a-H on the hydrazine residue giving a neutral complex, and both isopropylidine derivatives act as monobasic bidentate ligands giving only bis-complexes. In all cases chelation occurs through the (3-N atom and the S atom.805New data have been published on nickel-thiourea complexes. Ni(tu),(ClO,), is a 1:2 electrolyte in acetone, and n.m.r. data on this and the analogous dimethylthiourea complex show only octahedral [ N i ( f ~ ) , ] ~ at + -90°C with some dissociation to planar [Ni(tu),]'+ at higher temperatures. In the case of [Ni(tu),Cl,], the species [Ni(tu),Cl,] is present at all temperatures in acetone, and Ni(tu),Br, shows both planar [Ni(tu),Br]+ and tetrahedral [Ni(tu),Br,] at -90°C. Ni(tu),I, at -90°C consists of planar [Ni(tu),I]+ and a small amount of tetrahedral [Ni(tu),I,] in acetone.896Substituted selenoureas form Se-bonding complexes tetrahedral [NiL2X2] (X = halogen) and planar [NiL,](CiO,), and. in contrast to the thioureas, NiL6X2 and NiL,(CIO,), could not be prepared.'07 Ni(tac),Cl, is octahedral, whereas Ni(tac),X, (X = Br, I, NO,, or C10,) are all planar and [Ni(tac)Cl,] is polymeric (tac = thioacetamide)., 7 4 * 'O NN'-Dicyclohexyl- and NN'-dibenzyl-dithio-oxamide form the complexes [NiL,X,] (X = C1, Br, I, or C10,).809 The mono-thiocarbamate complexes [Ni(OSCNR,),] [R = Me, Et, Pr", The isoPr', or Bun, R, = (CH,), or (CH,),] have been propyl complex is dimeric in the vapour phase'" and low-polymeric or cyclic oligomeric structures are proposed for the others.' l 2 Bis-pyridine and bispyrrolidine adducts have been isolated." O. '' 1 : 1-Complexes of nickel(I1) with ethylenedithiodiacetate, diethylenetri'' thioacetate, and ethylidenetetrathiotetra-acetate have been reported."'. The structure of ethylenedithiodiacetatonickel(I1) dihydrate has been reported.813The potentially terdentate ligand, thiodiethanol, forms both 1 : 1 and 1 :2 complexes with nickel.' O9 NiC1,,6H20 reacts with Me,SnCl(SSeCNR,) (R = Me or Et) in ethanol to form [Ni(SSeCNR,)2].814 Ph,PS(Se)Na reacts with NiC1,,6H20 to give

'

'

C. Battistoni, G . Mattogno, A. Monaci, and F. Tarli, Inorg. Nuclear Chem. Letters, 1971, 7 , 981. M . F. Iskander and L. El-Sayed, J. Inorg. Nuclear Chem., 1971, 33, 4253. D. R. Eaton and K . Zaw, J. Arne. rhem, SOC..1972,94,4394. T . Tarantelli and C. Furlani, J. In v-g. JVuclearChem., 1972,34, 999. R. R . Iyengar, D. N. Sathyanarayana, and C. C. Patel, J. Inorg. Nuclear Chem., 1972,34, 1088. G . C. Pellacani and G . Peyronel, Inorg. Nuclear Chem. Letters, 1972, 8, 299. J . Willemse, Inorg. Nuclear Chem. Letters, 1972, 8, 45. E. M. Krankovits, R. J. Magee, and M. J. O'Connor, Inorg. Nuclear Chem. Letters, 1971,7, 541. B. J. McComick and B. P. Stormer, Inorg. Chem.. 1972, 11, 729. J. Loub and J. Podlahova, Inorg. Nuclear Chem. Letters. 1971,7,409; J. Podlahova, J. Loub, and C. Novak, Acta Cryst., 1972, B28, 1623. T. Tanaka and N . Sonada. Inorg. Chem., 1971. 10, 2337.


313

[Ni(SSePPh,),],441 and the complexes [Ni(YPPh, CH .Ph,PY),] (Y = S or Se) have been prepared by deprotonation of (Ph,PY),CH, with BuLi followed by addition of a nickel halogeno complex anion. Both complexes are planar.26o The low-spin trigonal-bipyramidal complexes [Ni(SAs,)X](ClO,) [SAs, = As(o-C,H,AsPh,),(o-C,H,SMe), X = C1, Br, I, NCS, or CN] have been obtained and a structural study on the bromo-compound shows that two arsenic atoms and the sulphur atom occupy the equatorial plane, the other arsenic atom and the bromide atoms being axial. As is common in low-spin complexes, the axial Ni-As bond is shorter than the equatorial ones, and the Ni-S bond length indicates negligible R- bonding.8 The related compounds, [NiLXIBPh, [X = C1, Br, I, NCS, NO,,or CN; L = Sb(CH,CH,CH,AsMe,),] also show trigonal-bipyramidal co-ordination, and the electronic spectra of the series of trigonal-bipyramidal complexes of E(CH,CH,CH,AsMe,), (E = P, As, or Sb) show a normal spectrochemical effect, in contrast to the anomalous order, P > As <Sb, observed with the rigid ligands (0-Ph2E1C,H4),E2 (El = P or As; E2 = P, As, or Sb). This study also provided confirmatory evidence of a compression effect in nickel@) complexes of the rigid ligand Sb(o-C,H,EPh,),.816 Dimethyl(o-dimethylarsinophenyljstibine (stars) has been prepared, and the complexes [Ni(stars),](C10,), (square-planar) and [Ni(stars),X]Y (X = Cl, Br, I, NO,, or NCS, Y = C1, Br, I, NO,, or BPh,) (square-pyramidal) have been i ~ o l a t e dl .7~ The reaction of [Ni(stars)Br,] with [Ni(tas)Br,] [tas = (dimethylarsinopropyl)arsine] gives [Ni(stars)(tas)]Br, which has trigonal-pyramidal co-ordinatiqn of the cation.' Ni(C104),,6H,0 reacts with tris-(0-dimethylarsinopheny1)stibine(Sbtas) to give [Ni(Sbtas),](ClO,),. Spectral studies indicate a square-pyramidal geometry for the ~ a t i o nl 9. ~ Other Compounds. The structure of (Me,N),[Ni(B,,H,,),] has been determined. The nickel atom is bonded to eight boron atoms and fuses two parallel polyhedral fragments. Extended Huckel M O calculations on the [Ni(B,,Hl2),I2- ion shows that the primary metal bonding comes from the 4s atomic orbital of nickel.',' Nickel(II1) and Nickel(1v) Compounds.-[Ni(S,CNBu",),] reacts with I, at - 30°C in ether to give [Ni(S,CNBu;),I], although the magnetic moment of the complex (1.33 BM) is somewhat low for low-spin nickel(1rr). E.s.r. evidence indicates square-pyramidal co-ordination.821 [Ni(ttas)Br,] [ttas = bis(odimethylarsinophenyl)methylarsine] reacts with Br, in CHC1,-CCI, to give [Ni(tta~)Br,].~~' NiC12,6H,0 when treated with S,OS2- in acetone-aqueous ammonia solution in the presence of dapdH, (2,6-diacetylpyridine dioxime)

'

'15

'" '19

M. Matthew, G. J. Palenik, G. Dyer, and D. W. Meek, J.C.S. Chem. Comm.,1972, 379. C. A. McAuliffe and D. W. Meek, Inorg. Chim. Acta, 1971,5, 270. B. R. Cook, C. A. McAuliffe, and D. W. Meek, Znorg. Chem., 1971, 10, 2676. J. Dalton, W. Levason, and C. A. McAuliffe, Inorg. Nuclear Chem. Letters, 1972,8, 797. L. Baracco, M. T. Halfpenny, and C. A. McAuliffe, Chem. Comm., 1971, 1502. L . J . Guggenberger, J. Amer. Chem. SOC.,1972,94, 114. J. Willemse, P. H. F. M. Reuwette, and J. A. Cras, Inorg. Nuclear Chem. Letters, 1972, 8, 389.

Inorganic Chemktry of the Transition Elements

314

gives diamagnetic Ni(dapd),, which can also be obtained by treating [Ni(dapdH,),](ClO,), with pyridine in MeOH-MeCN and Br, in CCI,. Indirect evidence was presented that the product contained NiW, and not cationstabilized radical ligands.'o Oxides and Su1phides.-The synthesis of SrNiO, and SrNiO, has been reported. The former has a perovskite structure whereas the latter is hexagona1.822The structure of ct-Ni,S, shows three non-equivalent sulphur sites and five non-equivalent nickel sites per unit cell. Four of the nickel sites are square-pyramidally disposed and the other tetrahedrally disposed towards sulphur. There is evidence for metal-metal bonding.823 6 Copper Copper(i).-Halides and Cyanides.The cation, [Me,N=CH,]+, which has been reported previously by Eschenmoser (Symposium on Stereochemistry, Shefield, 1970) is potentially useful in stabilizing low-valent metal complexes, and its reaction with Cu(C0)Cl has been examined. The results are outlined in Scheme 9. Cu(C0)Cl + i[(Me,N=CH,)+Br-j

-co

[Cu,(CO)(Me,N=CH,)Cl,Br] ,

I20"C

1 (Me,N=CH,)+(Cu,Cl,Br)-

+

-cUcl

Wacc1 - cu-II

+ CUCl

CH,

Br-

NMe,

20°C

oc

\ CH, pII CI NMe,

+ Br-

Scheme 9

Similar reactions with NO were also briefly reported.824Cu,O reacts with aqueous KI to give CuI; and C U I ; . ~ ~ ~ The reaction of K,[Cu(CN),] with CuS0,,6H20 gives the mixed Cu*CuI1 complex, [CU"CU:(CN),],SH,O.~~~The structure of the similar complex, 822

823 824

B25 826

Y. Takeda, T. Hashino, H. Miyamoto, F. Kanamuru, S. Kume, and M. Koizumi, J . Inorg. Nuclear Chem., 1972,34, 1599. M. E. Fleet, Acta Cryst., 1972, B28, 1237. R. Mason and G . Rucci, Chem. Comm., 1971, 1132. E. M . Gorelova and V. A. P'yankov, Russ. J . Inorg. Chem., 1972, 17, 359. C. Kappenstein and R. Hugel, Compt. rend., 1972, 274, C, 362.


315

[Cu',Cu"(NH,),(CN),] has been reported. The copper(I1)atom is co-ordinated to three NH, groups and to the N atoms of CN groups, giving distorted octahedral co-ordination, and the copper(1) atoms are co-ordinated to three CN groups in trigonal planar array. Disorder amongst some of the CN groups makes it impossible to distinguish the C and N atoms.827The same group have also reported the structure of [CU'~CU~(~~),(CN),],H,O, which contains discrete [Cu(H,O)(en),I2 -t ions and polymeric [Cu,(CN);-], ions. The anions form a three-dimensional cage-like network with Cu' ions tetrahedrally linked by CN- ions, and the cations fit into holes in this network.828

Complexes. N-Donor ligands. CuX (X = C1 or Br) reacts with Me,C=C(CN), to form Me2C=C(CN),,2CuX, which may be polymeric or have bridging dinitrile ligand~.~,'L,CuCl, (L = Ph,P, Ph,As, or Ph,Sb), when treated with Na(NCBR,) (R = H or Ph) in ethanol-chloroform yields L,Cu NCBR, which all contain Cu-N bonds in the solid state and in chlorinated solvents. However, in MeCN, the Ph,P complex is a weak electrolyte and i.r. evidence indicates that it may be a dimer with both Cu-NBPh, and Cu-HBH,CN linkages.830 [Cu(py),]ClO, has been obtained by electrolytic reduction of the corresponding Cu" complex. A structural study shows the co-ordination to be tetrahedral.831 [CuL,]ClO, (L = 2-picoline, 2,5-lutidine, 2-Etpy, 2-Pr'py) have also been prepared, and X-ray studies confirm a distorted trigonal planar geometry.832[CuCN(paz)] and [CuCN(4-CNpy)] both contain zig-zag planes of CuCN units linked via the N atoms of the ligands. Both complexes are p ~ e u d o - t t t r a h e d r a l CuBr,MeCN .~~~ also has an infinite chain of [CuBr] units arranged in such a way that each copper atom is surrounded by three bromine atoms and one nitrogen atom in a tetrahedral array.834 0-,S-, and Se-don& ligands. Mass spectral evidence has been obtained for the presence of tetrameric species of copper(1) benzoate, acetate, trifluoroacetate, and f ~ r m a t e . ~It, is ~ difficult to find simple copper complexes that undergo repeated oxidation-reduction cycles in a chemically reversible way, although copper-containing enzymes show this property. It has been suggested that this is because of the near tetrahedral co-ordination of copper in enzymes. The tetrahedral complex [CU"(W,,O,,)]~ -, however, can be reduced to the corresponding Cut species and aerial oxidation of the dark-red solution of the Cu' complex can be achieved. This 12-tungstocuprate(r)anion is the first example of a heteropoly-species with a univalent central metal atom, and the reduction 827 828

829

830 831 832

833 834 835

R . J . Williams, D. T. Cromer, and A. C. Larsen, Acta Cryst., 1971, B27,1701.

R.J. Williams, A. C. Larsen, and D. T. Cromer, Acta Cryst., 1972, B28,858. S.K. Smirnov, 0. G . Strukov, S. S. Dubov, A. M. Gribov, and E. L. Gal'perin, Russ. J . Inorg. Chern., 1971, 16, 1159. S. J. Lippard and P. S. Weckler, Znorg. Chern., 1972, 11, 6. A. H. Lewin, R. J. Michl, P. Ganis, U. Lepore, and G. Avitabile, Chern. Cornm., 1971, 1400. A. H. Lewin, R. J. Michl, P. Ganis, and U. Lepore, J.C.S. Chern. Cornrn., 1972, 661; H. D. DeAhna and H. D. Hardt, Z . Anorg. Chern., 1972,387,61. D. T. Cromer and A. C. Larsen, Acta Cryst., 1972, B28, 1052. M. Massaux, M. J. Bernard, and M. T. Le Bihan, Acta Cryst., 1971, B27,2419. D.A, Edwards and R. Richards, Inorg. Nuclear Chern. Letters, 1972,8,779.

316


process results in only small changes in the copper stereochemistry. Thus no dissociation of the multidentate ligand need occur and this allows the repeated redox The structure of [Cu(SPMe,),]ClO, was reported in Volume 1 and a range of analogous complexes [CuL,]X (L = Et,PS, PriPS, Ph,PS, Ph,AsS, PhMe,AsS, or Ph,SeS; X = ClO, or BF,) have now been prepared by treating an ethanolic solution of CuX2,6H,0 with an ethanolic solution of L in 1 :(3-4) mole ratios. In some cases the solutions were treated with SO, to enhance reduction prior to addition of the ligand. The complex cations show only partial dissociation in solution and show no tendency to add a fourth ligand. They represent the first series of three-co-ordinate copper(1) comp l e x e ~ . ~Treatment ,~ of [( 1,5-cod)CuX], with [(x-Cp),Ti(SR),] (R = MePh; X = C1 or Br) in toluene gives [(K-C~),T~(SR),CUX]~ (n unknown). Spectral studies were limited by poor solubility, but the authors suggest the presence of some Cu' + Ti bonding.838 1 : 1 Complexes of Cu' and 1,5-bis-(2-methylethy1thio)pentane have been reported. They are polymeric, and spectral studies indicate no sulphur bridging. Their thermal decomposition has also been The anion (EtO),PSe; reduces Cu(ClO,), to [Cu{ Se,P(OEt),}], which is possibly trimeric in solution.566 P-Donor ligands. The copper@ complexes, CuL,X [L = PPh,, PMePh,, PPh,(o-C,H,OMe), PPh,OMe, or PPh,OEt], [CuX{Ph,P(CH,),PPh,)], (X = N, or NCS) have been reported. The and [CU,{P~,P(CH~)~PP~~)~X,] azide complexes react with CS, and CF,CN, by 1,3-dipolar cycloaddition reactions, to yield thiothiatriazolato- and perfluoromethyltetrazolato-complexes, respectively. The former decompose both thermally and photolytically, whereas the latter are stable.839The structures of [Cu,(N,),{(CH,PPh,),),]840 and [CU,(CF,CN,),((CH,PP~~)~)~]~~~ have been reported. Both are centrosymmetric dimers and have tetrahedral co-ordination from a bidentate phosphine, a bridging phosphine, and the azide group or the N-213) atom of the perfluoromethyltetrazolato-ligand, respectively. The related dimer [Cu,Cl,(PPh,),] contains both four- and three-co-ordinate Cu'. There are two chloride bridges and two Ph,P molecules bonded to one copper and one to the other. Shorter bond lengths are observed around the three-co-ordinate metal atom.842 General methods of preparation have been reported for Cu'-EPh, (E = P, As, or Sb) complexes. Reduction of Cu" salts with Ph,P and the direct reaction of Cu' with Ph,P have been examined and displacement reactions of [(Ph,P),CuCl] and [Ph,PCuCl], by charged or uncharged ligands have been used to prepare compounds such as [(Ph,P),CuSPh], [(Ph,P),CuOPh], [Ph,PCu836 837

'" 839 840 841

842

D. R . Wexell and M. T. Pope, Chem. Comm., 1971,886. J. A. Tiethof, A. T. Hetey, P. E. Nicpon, and D. W. Meeks, Znorg. Nuclear Chem. Letters, 1972, 8, 841. P. S. Braterman and V. A. Wilson, J . Organometalfic Chem., 1971, 31, 131. R.F. Zioli, J . A. Thich, and Z. Dori, Inorg. Chem., 1972, 11, 626. A. P. Gaughan, R. F. Zioii, and Z . Dori, Znorg. Chem., 1971, 10,2776. A. P. Gaughan, K. S. Bowman, and Z. Dori, Znorg. Chem., 1972,11,601. V. G. Albano, P. L. Bellon, G. Ciani and M. Manassero, J.C.S. Dalton, 1972, 171.


317

(x-Cp)], [Ph,PCuC=CPh], [Ph,PCuCl],py, [Ph,PCuN,],py, and [(Ph,P),CuBPh,]. Adducts of Ph,P*CuCl with CHCl,, CS,, and DMF have been reported, and [(Ph,P),CuN,] decomposes smoothly in excess Ph,P to [Ph,P=Wu],. Molecular weight measurements indicate that many of the complexes must be t h r e e - ~ o - o r d i n a t e The . ~ ~ ~reaction of copper(I1) halides or CuI with Ph,As or Ph,Sb give 1 : 1, 3 :2, 2 : 1, and 3 : 1 complexes depending upon the conditions and stoicheiometries employed. The Group V ligands are very labile in solution and are completely displaced by reaction with excess bidentate ligands such as phen. However, under controlled conditions, both uni- and bi-dentate ligands (L) yield [CuX(EPh,)L] (E = As or Sb, X = halide).844 The structure of [Cu(PPh,Me),NO,] shows three different Cu-P bond lengths and unidentate NO, ~ o - o r d i n a t i o n . ~The , ~ reaction of Cu(N0,),,3H,O and PPh, gives [Cu(NO,)(PPh,),]; however, Ph,E (E = Sb or As) are not such powerful reducing agents and the complexes [Cu(NO,)(EPh,),] are prepared from copper(I1) nitrate and EPh, in the presence of the reducing agent, PBu';. The nitrate complexes react with bidentate ligands (L) such as phen to give [Cu(NO,)(EPh,)L] and under mild conditions, [Cu(NO,)(PPh,),] also forms the ionic complex [Cu(PPh,),L]NO,. The action of excess L on ~ complexes [CuNO,(EPh,)] (E = As or Sb) yields [ C U L , ] N O , . ~ ~The [Ph,_,Me,ElmCuX (n = 0,1, or 2; rn = 3,2, or 1.5; E = P or As; X = C1, Br, or I) have been studied, and the effects of the substituents on E, the nature of E and the choice of X on the extent of ligand dissociation from the rn = 3 complexes have been discussed. The most striking influence is stereochemical, but the arsine ligands are more highly dissociated than the p h o ~ p h i n e s . ~ ~ ~ The complexes [CuX(Me,PPMe,),] have been reported.261 Ph,P(CH,)"PPh, (n = 1, dpm; n = 2, dpe) form the complexes [Cu,X,(dpe),], [Cu,X,L], [Cu,X,L,], [Cu,X,L,], and [CuXL] (L = dpe and d ~ m ) . '[(pyPPh,),~~ Cu,CI,] is chlorine-bridged with both tetrahedral and three-co-ordinate

copper(^).^^ Mixed donor ligands. On the basis of spectral, magnetic, and conductivity data the secondary copper(1) dithizonate is assigned structure ( 183).849The complex CuCl(thioacetamide) is polymeric with co-ordination uia the S atom of the

843

845 846 847

848 849

W. T. Reichle, Znorg. Chim. Acta, 1971, 5 , 325. F. H . Jardine and F. J. Young, J. Chem. Soc. ( A ) , 1971,2444. M. Matthew, G. J. Palenik, and A. J. Carty, Canad. J. Chem., 1971,49,4119. F. H. Jardine, A. G. Vohra, and F. J. Young, J. Inorg. Nuclear Chem., 1971, 33, 2941 S. J . Lippard and J . J. Mayerle, Znorg. Chem., 1972, 11, 753. N. Marsich, A. Camus, and E. Cebulec, J. Inorg. Nuclear Chem., 1972,34,933. W. Kemula and T. Ganko, Chem. Comm., 1971, 1063.


318

ligand,80 and 2-mercaptobenzthiazole forms 1 : 1 complexes with copper(1) compounds which also appear to be polymeric.g50Cu' complexes of o-dimethyland o-diphenyl-arsinoaniline, l-amino-2(diphenylarsino)ethane,and o- and p-dimethylaminophenyldimethylarsinehave been reported.79s* 85 Copper(i1). --Halides. The complex [CuF(aq)] has been identified in copper(I1)fluoride solutions.60 The structure of Cs,Cu2C1,,2H,O has been reportedgs2 and the anion is shown in (184). The salts D,[CuX,] ( D = the 2,4-dimethyl+

c1 C1 \ /cl\ / H,O-CU-CC~-CU-OH, c1' 'C]' 'c1 lH-1,5-benzodiazepinium ion, X = C1 or Br) have been isolated.65 The reaction of BBr, with anhydrous CuCl, gives anhydrous CuBr,.2g1 CuX,,nCu(OH),,zNH,,xH,O salts have been obtained from the CuX,-NH,-H,O system (X = halide).g53 Complexes. N-donor ligands. The complexes [Cu(allylamine),SO,] and [CUL,(NCO),]~~ (L~ = PhNH,, 0-,rn-, p-toluidine, p-CI. C,H4NH,, or p-I C,H,NH,) have been reported. When solutions of Cu" salts are treated with hydrazine hydrate, amorphous complexes of Cu' contaminated with basic salts are formed. However, the use of N,H,,HCl in neutral or weakly acidic solutions gives the crystalline compounds [CuX,(N,H,),],nH,O (X = :SO, or NO,, n = 2: X = C1; n = l).gss [ C U ( N N - M ~ , ~ ~ ) ~(nC=~ ,1]or 2) have been isolated and various physical (X, O =~ acetate or properties were reported.856 [ C U ( N - M ~ ~ ~ ) X , ] , ~ H ~~ oxalate) and [CuL,(NO,),] (L = en, NN-Me,en, NN-Et,en, or N-2-hydroxyethyl-1,3-pr0panediamine)~~~ have also been prepared. When L = en or NN-Me,en the NO, groups are N-bonded; the other two NO, complexes contain nitro-groups. [Cu(tmen)en]X,,nH,O (X = C104, n = 0; X = NO,, n = 1; X = +SO,, n = 4), [Cu(tmen)L]ClO, (L = gly or acac) and [Cu(tmen)OX],4H,O (tmen = NNN'N'-Me,en) have been prepared and their electronic spectra examined.8s9 The complexes [Cu(N-benzylen),(SCN),] and [Cu(Nbenzylen),(SeCN)]NO, are both octahedral,3g2 whereas the [Cu(NN'-

-

850 851

852 853 854

855 856

857

859

M. M. Khan and A. U . Malik, J . Inorg. Nuclear Chem., 1972, 34, 1847. L. Volpini, B. Zarli, and G. G. De Paoli, Inorg. Nuclear Chem. Letters, 1972, 8, 309. W. Vogt and H. Haas, Acta Cryst., 1971, B27, 1528. A. K. Kirakosyan, Russ. J . Inorg. Chem., 1971, 16, 1297. J. Kohout, M. Quastlerova-Hvastijova, and M. Kohutova, Z . Nuturforsch., 1971,26b, 1366. R. Y. Aliev, M. N. Guseinov, and N. G . Klyuchnikov, Russ. J . Inorg. Chem., 1971, 16, 574. R. Nasanen, E. Luukkonen, H. Palonen, and M. Sivonen, Suomen Kern., 1971,44,93; R. Nasanen, E. Luukkonen, M.-L. Ollikainen, and K. Smolander, ibid., p. 128. R . Hamiliinen, Suomen Kem., 1971,44, 89. A. Pajunen and S. Pajunen, Suomen Kern., 1971,44,381. Y. Fukada and K . Sone, BulI. Chem. SOC.Japan, 1972,45,465.


319

dibenzylen)Br] cation exists in both trigonal-bipyramidal and squarepyramidal forms.860The reaction of CuX,,nH,O with dpt (3,3’-diaminopropylamine) and either en or pn gives the square-pyramidal five-co-ordinate complexes [Cu(dpt)en]X, and [Cu(dpt)pn]X, (X = C1, Br, I, or C104).861 Similar octahedral complexes [Cu(trien)en]X, (X = ClO, or BPh,) have been reported.680 O ] always .*~~ CuSO, reacts with py and KI to form [ C U ( ~ ~ ) ~ I ~ HIt~ has been assumed that, in aqueous solution, [C~(bipy),(H,O),]~+has exclusively cis stereochemistry because of the steric repulsion between the 6- and 6’hydrogen atoms; however, Sige1863has concluded that the reason is electronic and not steric. Potentiometric studies on the Cu”-imid-OH- system (imid = imidazole or hydroxyimidazole) indicate the presence of Cu(imid);+ (n = 1,2, 3,4,or 6) and small amounts of [Cu2(OH),(imid)J2+ in solution. The solid compounds Cu(imid),(ClO,), and Cu3(imidH),(imid),(C104), were also identified.864 The square-planar complexes [Cu(2-Meimid),I2 (X = C10, or BF,) and the octahedral complexes [Cu(2-Meimid),]X2 (X = C10, or BF,) and [Cu(NB~”irnid)~]X,(X = C1, Br, I, or NCS; n = 1-6) have been i ~ o l a t e d . ~ ~ . ~ ~ 2-Methylbenzimidazole ( L ) forms the distorted six-co-ordinate complexes, [CuL,X,] (X = C1, Br, or NO,).399 Pyrazole and 3(5)-methylpyrazole complexes of copper(I1) nitrate and isothiocyanate have also been reported.76 A study has been made of the addition of water and alcohols to the azomethine group of the copper(I1) complexes of NN’-bis-(2-pyridylmethylene)propane- 1,2-diamine and NN’-bis-(2-pyridylmet hylene)-2-methylpropane- 1,2diamine. These complexes have the same chelate ring size as the ethylenediamine analogue for which such a reduction was first observed and, in agreement with the suggested steric origin for this complex, the reaction also occurs with the propane d i a m i n e ~ . ~NN”N”N”’N”’-Hexamethyl-3,6-diazaoctane,~ 1,8-diamine (L) forms the five-co-ordinate complexes CuLX, (X = Br. SCN, or +SO4) and the four-co-ordinate complexes CuLX, (X = C10, or BPh4).684 Complexes of a range of macrocyclic ligands (L) have been studied by cyclic voltammetry, and the irreversible or quasi-reversible reactions Cu’L + Cu”L -+ Cu’I’L were observed.244 The complcxes [Cu(CR)](ClO,),H,O, [Cu(CR)X]ClO,,nH,O (X = C1, Br, or I, n = 1; X = NCS, n = 0), [Cu(CRH)](ClO,),H,O and [Cu(CRH)X)CIO, (X = C1, Br, or I) [CR = (185) CRH = (186)] have been isolated. Conductance studies show that the halogenoperchlorate complexes are formally five-co-ordinate in solution.866 The complexes of the 13-membered macrocycles [Cu”(AT)X] (X = NO,, I, Br, SCN, or PF,) and [Cu(ATH)X,] (X = I or PF,) (AT = 11,13-dimethyl-1,4,7,10-tetra-azacyclo+

860

862

863 864 865

866

K. C. Pate1 and D. E. Goldberg, Znorg. Chem., 1972, 11, 759. G. Ponticelli, Znorg. Chim. Acta, 1971, 5,461. B. K. Mohaptra, Chem. and Znd., 1972, 383. H. Sigel, Znorg. Chim. Actn, 1972, 6 , 195. S. Sjoberg, Acta Chem. Scand., 1971, 25, 2149. M . Cressey, E. D. McKenzie, and S. Yates, J . Chem. SOC. ( A ) , 1971, 2677. L. F. Lindoy, N. E. Tokel, L. B. Anderson, and D. H. Busch, J. Coord. Chem., 1971, 1, 7 .


320

trideca-10,12-diene and ATH = 11,13-dimethyl-l,4,7,l0-tetra-azacyclotrideca10,13-diene) have been isolated. The (AT) and (ATH) complexes can be interconverted in solution by reversible protonation of the co-ordinated ligand (Ka = The relative acidity of the ligand in [Cu(ATH)X,] is a thousandfold less than in the analogous nickel complexes.867 NN’-Bis-(2’-formyl-4nitropheny1)-1,3-diaminopropane and its ethylene analogue both condense with 1,2-diaminoethane, 1,3-diaminopropane, 1,2-diamin0-2-methylpropane, 1,2-diaminocyclohexane, or 1,2-diaminobenzene in the presence of Cu(OAc), to give the complexes (187).402The 12x macrocyclic complex [Cu(MeHMe-

(186)

(en),}] has been prepared from Cu(OAc), and H,[MeHMe(en),] (188).247 The complex (189) has been prepared by the template reaction of 2,9-diaminoand 2,9-dichloro-l,l0-phenanthroline in the presence of K,CO, and CuCl, in nitrobenzene. A non-template synthesis has also been reported.868 The dianil complexes (190) have been prepared.685 Potentially bidentate 1,3,5-triphenylformazan and potentially terdentate 1-(2’-carboxyphenyl)-3,5diphenylformazan and 1-(2’-hydroxypheny1)-3,5-diphenylformazanare stoicheiometrically oxidized to the corresponding tetrazolium salts by CuC1, in 867 868

J. G. Martin, R . M . C. Wei, and S. C. Cummings, Znorg. Chem., 1972, 11,475. S. Ogawa, T. Yamaguchi, and N. Gotoh, J.C.S. Chem. Comm., 1972, 577.


32 1

(189)

0 P{

:\..

(190) R

=

H, 2-Me, 3-Me, 4-Me, or 4-Me0

MeOH. In the presence of air the oxidation of the triphenyl compound is catalytic. The triphenyl compound is also oxidized by Cu(OAc), in MeOH, but the other two compounds react with this reagent to give 1:l complexes.412 1,5-Di-(2’-hydroxyphenyl)-and 1-(2’-hydroxypheny1)-5-(2”-carboxypheny1)-3substituted formazans react with Cu(OAc), in MeOH to give square-planar copper(1r) complexes. In contrast, under comparable conditions, 1,5-di-(2’carboxyphenyl)-3-~ubstituted formazans give copper(r1) complexes containing two molecules of water, which are probably octahedral. With CuCI, in MeOH these 3-substituted formazans undergo two competing reactions: metal complex formation and oxidation to tetrazolium salts. The relative importance of either of the competing reactions is governed by the nature of substituents in the 3-po~ition.~~’ Tetragonal complexes of a range of 5-substituted tetrazoles have been prepared.414 The square-planar complexes, [CuCl,(dpq)], [Cu,Cl,(dmpq)], and [CuBr,(dpmq)], the octahedral complexes [CuCl,(dpmq)] and [CuBr,(dpdmq)], and the tetrahedral complex [CuBr,(dpdmq)] have been reported [dpq, dmpq, dpmq, and dpdmq (191a-d)]. However, the geometry of [CuBr,(dpq)] is uncertain.391*392 The 1,1,4-trimethylpiperaziumcation (L+) forms the complexes [CuX,(L+)] (X = C1, Br, or I), although co-ordination of the cation is weak and, in the presence of traces of water, (LH)[CuX,] is formed.” 869

X

R. Price, J . G e m . SOC.( A ) , 1971, 3385.

322


Phthalimide (L ’), succinimide (L’), glutarimide ( L3),pyrid-2-ylcarboximide-Nt oluene-p-sulphonyl(L4)and benzofur-2-ylcarboximide-N-toluene-p-sulphonyl (L’) react with copper salts at pH 8.5 in 70% aqueous methanol to form ~’ K,[Cu(L),(MeOH),] (L = L’, L2, or L3), Cu(L4), and C U ( L ’ ) ~ . ~The complexes [Cu(L’),(RNH,),] and [CU(L,),(RNH~)~] (R = aliphatic group) have also been reported.”* R3

k4 (191) a; R’ = H , R 2 = R 3 = R4 = Me(dpq) b; R’ = R2 = R3 = R4 = Me (dmpq)

c; R’ = Me,R2 = R3 = R4 = H(dpmq) d ; R’ = R2 = Me, R3 = R4 = H (dpdmq)

The oxime complexes [Cu(LH2)X2],nH20(X = C1 or ClO,, n = 0, 1, or 2) and [Cu(LH)X] (X = Cl, Br, or C10,) (LH2 = 4,4,9,9-tetramethyl-5,8diazadodecane-2,ll -dionedioxime) have been isolated. An X-ray structural study shows [Cu(LH)Br] to contain dimeric [Cu(LH)]f units in which the copper atoms are trig~nal-bipyrarnidal.~’~ 0- and S-donor Zigands. [Tl,Cu(CO,),] has been reported.871 Isothermal evaporation of a solution of CuSO, and CsS0,at 80°C gives [Cs,Cu,(OH),(S0,),],2H20.872 The reaction of HClO, with Cu(OAc), in acetic acid shows the equilibria +

Cu,(OAc), Cu,(OAc),

+ 2HC10, + 4HC10,

2Cu(OAc)C10, + 2HOAc + 4HOAc

s 2Cu(C104),

With LiOAc in acetic acid the equilibria Cu,(OAc), Cu,(OAc),

+ 2LiOAc + Li,Cu,(OAc), + 4LiOAc 2Li,Cu(OAc),

were set up.873 The dinuclear complexes, [ C U , ( O A ~ ) ~ ( O , C C H ~,2L,nC~)~] MeOH (L = P-naphthoquinoline or quinoline) and [Cu2(OAc),(0,CCH,F),],870

J . W. Frazer, G . R. Hedwig, H. K. J. Powell, and W. T. Robinson, Austrol. J . Chem., 1972, 25, 747.

872 873

H . Seidel and R. Lemor, Z . Narurforsch., 1971, X b , 1193. M . Tardy, J. M . Bregeault, and G. Pannetier, Bull. SOC.chim. France, 1971, 3935. K . Sawada, H. Ohtaki, and M . Tanaka, J . Inorg. Nuclear Chem., 1971,34,625.


323

2-quinoline,nMeOH (n not established) have been prepared. * 74 The reaction of Cu2+ and 2-thiophencarboxylate in water (pH 5) gives a dinuclear complex, The gluconate complexes [Cu(C,H 007)2] [Cu,(C,H,SC02),],2H, 0.875 and [Cu(C,H,,O,)]have been obtained, although their formation and stability is very pH dependent.876 Copper(r1) compounds of d, 1, and dlmandelate,,,' hydroxymethylenenorcamphorate,299 phenylglycollate,86 3k e t ~ g l u t a r a t e and , ~ ~ b e n ~ i l a t have e ~ ~ also ~ been reported. The complexes [Cu(hfac),L] (L = PPh,, PMePh,, PMe,Ph, PEt,, PBu,, AsPh,, OPPh,, SPPh,, OAsPh,, or SAsPh,) and [Cu(hfac),L,] (L = PPh, or AsPh,) have been isolated.877Thermally stable, low-melting bis-chelates of heptane-2,4-dione, nonane-4,6-dione, 5-ethylheptane-2,4-dione, and 3,7-diethylnonane-4,6-dione have been ~ r e p a r e d7 .8~4-MepyNO reacts with Cu(ClO,), to produce [(4-MepyNO),Cu](C104), and a little [(4-MepyN0)6Cu](C104)2.879 2-, 3-,and 4-CNpyNO form the complexes, [CuC12(4-CNpyNO)],, [CuCl,L,], [CuL,](ClO,),, (L = 2-, 3-, or 4-CNpyNO), and [CuLk](BF,), (L' = 3- or 4-CNpyNO)., The complexes Cu(Ph,PO),(BF,) have been reported,92 and Cu(BF,),,6H,O reacts with trimorpholinophosphine oxide in acetone-triethylorthoformate a1 room temperature to give [Cu(MORPO),](BF,),, which is the first cationic tetrahedralcopper(II)complex.880Thecomplexes [(CuPhP(O)(NMe,), ),]X2 (X = C10, or BF,) and [(CuPhP(0)(NMe,),},C12] have been isolated and their stability related to analogous triphenylphosphine oxide and hexamethylphosphoramide c ~ m p l e x e sHexamethylphosphoramide .~~ (HMPA) and nonamethylimidodiphosphoramide (NIPA) form the complexes, Cu(HMPA),(CIO,), and Cu(NIPA),(ClO,) (both octahedral), [CuSO,(NIPA)], and C U ( O A C ) , , O . S N I P A . ~ PP-Dialkyl-NNN'N-tetramethylpyrophosphora~.~~~ mide (L) forms [CuL,](CIO,),, which has oxygen rather than nitrogen coordination.432 Copper(rr) phenylphosphonate and its monohydrate are both

,

Complexation of Cu" by tetramethyl- and tetraethyl-dithio-oxamide has been investigated and the complexes CuLX, (X = C1 or Br) and CuL,(ClO,), were identified.88 CuL, (LH = R'R2CN0,H) (R' = H, R2 = Ph, p-MeC,H,, or o-MeC,H,; R' = R2 = Ph) have planar structures. In donor solvents, the adducts [CuL,(py),] and [CuL,(DMSO),] are formed.881 The complex [Cu(SCN),]- has been observed in studies on the CuONH,CNS-NH,NO,-H,O system.882 3-Diphenylphosphinothioyl-1-phenyl874

87s

878

879

882

L. N. Milkova, Y. V. Yablokov, A. V. Ablov, and V. V. Gavrilov, Russ. J . Znorg. Chem., 1971, 16, 1625. J. Sokolik, J. Kratsmar-Smogrovic, and S. Surka, Z . Naturforsch., 1972, 27b, 723. V. K. Zolotukhin, Z. G. Galanets, and V. K. Gubarenko, Russ. J . Inorg. Chem., 1971, 16, 1421. R. A. Zelonka and M. C. Baird, Canad. J . Chem., 1972,50, 1269. I . Yoshida, Y. Oono, H. Kobayashi, and K. Ueno, Bull. Chem. SOC. Japan, 1972, 45, 174. D. W. Herlocker, J . Inorg. Nuclear Chem., 1972, 34, 389. M. W. G. De Bolster, I. E. Kortram, and W. L. Groeneveld, Inorg. Nuclear Chem. Letters, 1972, 8, 751. D. P. Graddon and N. D. Harradine, Austral. J . Chem., 1971, 24, 1789. E. M. Gorelova and V. A. P'yankov, Russ. J . Znorg. Chem., 1971, 16, 1316.

324


thiourea, - 1,l-dimethylthiourea, and -1,l -diethylthiourea all behave as bidentate ligands in copper(@complex formation.439The complexes [MS2'SZ''IZ (S,' = maleonitrile dithiolate, S2" = Bu",NCS,, z = - 1 or 0) have been prepared. Voltammetric studies show that the complexes have E, values between those of the unmixed ligand complexes.741 Dithioterephthalic acid forms a copper(I1)complex for which structure (192) has been suggested.883

\

in

(192)

Mixed donor ligands. Cu(OAc), reacts with 3-formyl-5-methyl salicylaldehyde and either en or pn to form a 1 :1 complex. This reacts with more en or pn to form (193) and this in turn reacts with CuC1, to form (194).884Similarly, 3-formyl-5-methyl-salicylaldehyde dithiosemicarbazone forms (195),782and

(193)n

=

2 or 3

(194)n = 2 or 3

the reaction of copper(1r) N-alkylsalicylaldimine complexes with Cu(NO,), gives the dinuclear complex (196).768The structure of (197), prepared by a template reaction in methanol, has been reported; both copper atoms have square-planar ~ o - o r d i n a t i o n .The ~ ~ copper(I1)mixed chelates (198) have been prepared by the reaction of Cu" salts with acacH, en, and either salicylaldehyde, o-HO-acetophenone, o-HO-propiophenone, or o-HO-butyrophenone. The complexes have been extensively characterized and their spectra were discussed with regard to the expected bonding changes and those predicted by MO calculations.886 The neutral bidentate ligand formed from condensation of acetophenone and en (bape) forms the complexes Cu(bape)Cl, and [Cu(bape)a ~ a c ( H , O ) , ] ( C 1 0 , ) . ~The ~ ~ reaction of [Ni(en),]'+ with acetone has already A. V . Pandey and M. L. Mittal, Inorg. Chim. Acta, 1972, 6 , 135. 884

886

H . Okawa and S. Kida, Inorg. Nucfear Chem. Letfers, 1971, 7 , 751. J . A. Bertrand and C. E. Kirkwood, Inorg. Chim. Acta, 1972, 6 , 248. H . Kuska, M. F. Farona, P. Pappas, and S. Potterton, J . Coord. Chem., 1971, 1, 259.


325 R2

R'

(195)X = MeO, EtO, MeOC,H,O, PhCH20, N,, C1, or C,H,N2

(196) R2 = H, R' = Me, Et, Pr', Me,CHCH,, cyclohexyl, or PhCH, R2 = 5-C1,R1 = Me R2 = 3Me0,R' = Me X = NO,

(198) R

(197)

=

Me, Et, Pr, or H

been discussed. When the reaction with [Cu(en),]'+ is performed a complex of the linear quinquedentate ligand NH2CH2CH,NH CMe, CH,CMe:NCH,CH,NHCMe,CH,COMe is formed.766 The Schiff base N-hydroxyethylnaphthalideneimine forms a bis-complex with copper(I1) which may be either square-planar or tetrahedral.' O7 Two molecules of pyridine-2-carboxaldehyde condense with one of 1,1,1-tris(aminoethy1)ethane in the presence of Cu2+ to form [Cu (MeC(CH,NH,)(CH,N=CHpy), )I2 .' O 5 The condensation of salicylaldehyde with aspartic, glutamic, or a-aminopropionic acids gives Schiff bases which can act as ter- or quadri-dentate ligands. However, when a CU" salt is added to the base prepared from aspartic acid, hydrolysis takes place yielding copper aspartate. The complexes of the Schiff bases are better prepared by a template reaction between bis(salicylaldehydato)copper(rr)and the aminoacid, although the nature of the product is pH-dependent and, in some cases, polymeric compounds were obtained.' +

'

F. Jursik and B. Hajek, Coll. Czech. Chem. Comm., 1972, 37, 1651.

326


Reaction of CuCO, or Cu(OAc), with aspartic acid gives [(S)(+)-aspartatol. The influence of ring size on the stability of mixed ligand copper(I1)

cuIl888

chelates has been examined for a wide range of ligands including amino-acids. Formation of ternary complexes containing two five-membered chelate rings is favoured, and those with a five-membered and a six-membered ring are slightly less favoured.889 Square-planar CuL, complexes have been prepared, where L = L-leucinemethylamidate anion and L, = the quadridentate ligand, trimethylenediamine-NN'-di-isobutyricacid amidate d i a n i ~ n . ~ "A wellcharacterized 1 : 1 complex between Cu2+ and Gly-L-His has been reported. The terdentate peptide is bound by amino-N, ionized amide, and imidazole-N, and the corresponding Ni2+ and Pd2 complexes have the same structure. These 1:l complexes all undergo deprotonation at pH -9.6 that occurs together with a significant blue shift in the absorption spectrum. This suggests that an N-donor rather than an OH group is replacing water in the fourth co-ordination position, and quantitative spectrophotometry after ionization indicates the presence of tetrameric species.890 The complexes [CuLCl],H,O and [CuL(NO,)],O.SH,O [L = N-(2-hydroxyethyl)propane-l,3-diamine] have been prepared.'" N-Hydroxyethylethylenediamine (hen) forms the complexes [Cu(hen),X,] (X = C1, Br, NO,, or C10,) and [Cu(hen)X,] (X = C1 or NO,). The co-ordinated ligand condenses readily with acetone to form complexes of 7,9,9-trimethyl-3,6,10,13-tetra-azapentadeca6-en- 1 , 1 5 - d i 0 1 . ~The ~ ~ new stereospecific ligand NN'-bis-(2-~arboxyphenyl)ethylenedi-imine reacts with Cu2+ at pH 2.5-4.5 to form (199).892 +

CH-CH

It

It

II

It

0

0 (199)

N-Hydroxyurea-Cu2+ complexes have been reported.lo4 Acetylhydrazine forms the complex [CuLJCl, in which the ligands chelate via carbonyl and primary a m i n o - g r o ~ p s . 'Cationic ~~ complexes of other acyl hydrazines have been reported in which the ligands are in their keto-forms, although neutral complexes with the ligands in their enol forms can be prepared.458PhNHNSO reacts with Cu(OAc), in water to give [Cu(PhNNSO),],H,O, which is probably square-pyramidal with the ligands bonding via the oxygen atom and the

890

*"

892

F. Jursik and B. Hajek, C O N . Czech. Chem. Comm., 1972, 37, 1801. H. Sigel, P. R. Huber, and R. F. Pasternack, Inorg. Chem., 1971, 10,2226. P. J . Morris and R. B. Martin, J . Inorg. Nuclear Chem., 1971, 33, 2913. R. Nasanen, E. Luukkonen, H . Kalmi, and K . Nieminen, Suornen Kem., 1971,44, 327. D. S. Mittel, Inorg. Nuclear Chem. Letters, 1971, 7 , 737.


327

nitrogen atom next to the phenyl ring. The complex reacts with en in benzene to give [ C U ( P ~ N N S O ) , ~ ~ ] . ~ ~ ~ 2-Acetamidothiazole (acam) and 2-acetamidobenzothiazole (acamb) form the complexes [Cu(acam),Br,] and [Cu(acam)X,] (X = C1 or Br) in which the ligand is m-ordinated uia the carbonyl group and the thiazole-N, [Cu(acam),Cl,] and [Cu(acamb),CI,], which have amide-N and thiazole-N co-ordination, and [Cu(acam),X,] (X = NO3 or ClO,) and [Cu(acam)ClO,] which have carbonyl-0, amide-N, and t hiazole-N ~ o - o r d i n a t i o n . ~ ' ~ Four new dinuclear complexes with subnormal magnetic moments have been synthesized by the reaction of Cu(apxd), [apxd = NN'-bis-(3-aminopropy1)oximidatel with another Cu" compound such as [(bipy)Cu(NO, ),I or [(bipy),Cu(NO,),]. The complex [Cu,(apxd)(bipy),]NO, has both metal atoms in five-co-ordinate environments (200).894

n

Copper(I1) complexes of 8-amino-7-hydroxy-4-methylcoumarin,3 2 2 1,lOphenanthroline-2-carboxamide,2622 - ~ y r i d o n e ,2,3-di-(2-pyridine ~~ N-oxide)and q ~ i n o x a l i n e ,pyridine ~~~ c a r b o ~ y l a t e s ,1-(2'-pyridyl)-2-azonaphthol, ~~~ l-(2'-benzothiazolyl)-2-azonaphtho1452 have also been reported. The i.r. and n.m.r. spectra of copper(I1) dithizonate together with other physicochemical data indicate that the complex is dimeric with structure (201).849The Schiff bases S-methyl-N-isopropylidenedithiocarbazate(NSH) (NNSH)form the squareand S-methyl-N-(2-pyridyl)methylenedithiocarbazate

planar complexes [Cu(NS),] and [Cu(NNS)H,O(CIO,)] . 3 26 a-N-Methyl-Smethyl-P-N-(2-pyridyl)methylenedithiocarbazate(L')112and its 6-methyl893 895

W. K. Glass and J. 0. McBreen, Znorg. Nuclear Chem. Letters, 1971, 7 , 733. H . Ojima and K. Nonoyama, Z. anorg. Chem., 1972,389,75. C . Petitfaux and R. Fournaise, Bull. SOC.chim. France, 1972, 914.


328

pyrid-2-yl analogue (L2)267form the complexes [CuL'(H,O)]SO,, of uncertain geometry, and five-co-ordinate [CuL,X,] (X = C1 or Br). The reaction of Cu2 with szlicylaldehyde semicarbazone (HL) in the presence of various nitrogen bases gives [CuC1(HL)B],2H2O and [CuCl(HL)B],H,O (B = py, 3-picoline, or p-anisidine), and furaldehyde semicarbazone (HL') forms the complexes [Cu(HL 1)2](N0,)2, [CuL',], and [Cu(NO,),(HL')(p-anisidine)],H20.896 Anthralinic aldehyde selenosemicarbazone (aasecb) forms [Cu(aasecb)(N 0 3 ) 2 ],3.5H20 and [Cu(aasecb)(phen)(NO,), J , 2 H 2 0 which both contain the ligand in its terdentate form.600Pyruvamide thiosemicarbazone (L) behaves as a planar ligand bonding through the amido-N, hydrazine-N, and sulphur atoms in the complexes [CuX,L(H,O)] (X = C1 or Br) and [Cu(L-2H)(NH3)],0.5 H 0.'O 3 8-Quinolinecarbaldehydeselenosemicarbazide (Hseqn) forms CuX,(Hseqn)H,O (X = C1 or NO,) in which the ligand is also terdentate with NNSe c o - ~ r d i n a t i o n . ~ ~ ~ and 2,1,3Copper(I1) complexes of i s o t h i a z ~ l e 2,1,3-benzoselenadiazole ,~~~ morph0line-4-carbodithioate~~~ b e n z o t h i a ~ o l e , 't~h~i ~ p h e n e a l d o x i m e and ,~~~ have been reported. Thiodiet hanol, ethylenedithiodiacetate, and diethylenetrithiodiacetate all form 1 : 1 complexes with Cu2+.109.110 2-Pyridyldiphenylphosphine (L) forms the complex [L,CuCI,],H,O, which is possibly d i m e r i ~ . ~[(cdpp)CuX],X, ~' (cdpp = 8-quinoldiphenylphosphine; X = C1 or Br) are also dimeric with halogen bridges.264 o-Dimethylarsinoaniline (maa) o-diphenylarsinoaniline (paa) and l-amino-2-(diphenylarsino)ethane (ape) react with C u 2 + to form a variety of products. Thus [CuLJ(ClO,), (L = paa or maa) are formed, the latter being the first example of a copper(I1)-arsine complex. Other products formed are [Cu(maaO),(C10,),]EtOH, [Cu(maa)CuCl,], [Cu(maa)CuBr,], [Cu(ape),CuI,], and [Cu(apeO),(C10,),].795 Cu" is reduced by triphenylpho~phole,~~ +

,

Copper(m).-The cyclotetrameric Schiff base taab (140) forms complexes of Cu" which may be reduced with a relatively low pressure of hydrogen. However, unlike the nickel complex, in which the ligand is hydrogenated, the copper complexes undergo a one-electron reduction followed by electronic rearrangement to form [Cu"'(taab2-)]X (x = c1 or PF,). The parent copper complex is also reduced by elemental mercury to [Cu"'(taab2 -)](HgC13),3H20.704The effect of amino-ligands on radiolytically induced formation and decomposition of copper(Ir1)species has been studied and the spectra of copper(xI1)complexes of NH,, en, and amino-acids were reported.899The oxidation of Cu" with permanganate and ferricyanide in strongly alkaline solutions containing TeOiions gives the [Cu(TeO,),] - species.g00

896 897 898

899

N. M. Samus and V. G. Chebanu, Russ. J . Inorg. Chem., 1971, 16, 1423. B. T. Oloi, N. V. Gerbeleu, and A. V. Ablov, Russ. J . Znorg. Chem., 1971, 16, 1537. R.H. Hanson and C. E. Meloan, Inorg. Nuclear Chem. Letters, 1971,7, 461. D. Myerstein, Inorg. Chem., 1971, 10, 2244. G. I. Rozovskii. A. K. Misyanvichyus, and A. Y . Prokopchik, Rum. J . Inorg. Chem., 1972,17, 219.


329

Oxides.-The solubility of CuO in molten NaN0,-KNO, has been studied.g01 The preparation and structure of BaCu',O, has been r e p ~ r t e d . " ~ The structure of Cu,Mo,O, is of a previously unknown type; it contains almost regular MOO, tetrahedra, CuO, octahedra distorted in two ways, and CuO, tetragonal pyramids. The C u 4 polyhedra share three or four edges amongst themselves to form a kind of aggregate infinite chain, and the MOO, tetrahedra are separated from one another by sharing corners with Cu-0 polyhedra only.903

Physical Measurements on Copper Complexes. -Detailed discussion of papers concerned pu'rely with spectroscopic and magnetic data obtained for copper complexes is now covered by the Chemical Society Specialist Periodical Report 'Electronic Structure and Magnetism of Inorganic Compounds' (ed. P. Day), Volumes 1 and 2, and will not be included here. However, three papers of some significance are cited below and other papers on this subject listed in Table 5 . Table 5 Complex

Physicochemical method *

Ref.

BaCuF,, Pb,CuF, cscuc1,

mag i.r., R ir., R mag

a b

K,CuC14(H,0),

CuF,,6NH3 CuF,,8NH3 (X = CIO,, BF,, or NO,) Cu" complex of Schiff base formed from (R)-172-pnand acacH [CNl ,2-pn),(NO,),I

C

d

thermochem

e

ir., e, mag (temp. dependence studies) e

f 9

h 1

(n = 1 or 2, X = C1, Br, or NO,) [Cu(dien)X]Y,nH,O [Cu(dien)B]X, (X and Y are various anions: B = NH,, en, bipy, or dien) [Cu(py),](NO,), (x = 2,394, or 6 ) [Cu(bipy)(OH)I,X,,nH,O (X = SO,,n = 5 ; x = 1,n = 3: X = Br, n = 4: X = C104, n = 0) [Cu(bjPY),(H20),l2 + [Cu(bipyndylamine),](ClO4), CU"complexes of 1,5,9,13-tetraazatridecane 3,7-diazanonane-1,9diamine

e.s.r., i.r.

j

i.r. mag, e.s.r.

k 1

e.s.r. e, e.s.r. t hermochem

m n 0

*The following abbreviations are used in the Methods column: e = electronic spectrum; mag = magnetic study; thermochem = thermochemical study; R = Raman spectrum; pol = polarographic study; 901

'03

M. Fredericks and R. B. Temple, Inorg. Chem., 1972, 11,968. C. L. Teske and H. Muller-Buschbaum, Z. Nuturforsch., 1972, 27b, 296. L. Kihlborg, R. Norrestam, and B. Olivearona, Acta Cryst., 1971, B27,2066.


330 Complex

Physicochemical method

Ref:

[Cu( 1,5-diazocyclo-octane)2],2H20 Cu" complexes of substituted dipyrromethanes Cu" complexes of tetrakis(amin0methy1)methane CU(OAC)~,CU(OAC)~H~O Cu" dinuclear carboxylates A range of Cu"-halogenoacetates and adducts with dioxan and phenylene diamine [CulO,CCH,OEt),(H,O),I Cu" glycollate, lactate, hydrogen maleate, methoxy-, phenoxy-, and ethoxy-acetate cu"-propionates [Cu(O,CCFHMe),] [CU(O,CCFHM~)~] 0.5 dioxan Cu" complex of halogeno-propionates and their dioxan adducts [CU { 02 C(CH 2 12 Me) 2( H 2 )I2 [Cu(maleate)H,O] H2[Cu(maleate),]4H2O Cu"-2-furancarboxylate tri ydrate A range of Cu"-substituted benzoates Cu"-saccharate, -lactobionate, -gluconate, and -mucate [Cu( H,0),]TiF6,NH,F Cu"-acac, -benzoylacetone, -anisoylaceton e. and -dibenzoylmethane complexes Cu(acac), in CHC1,-toluene glass [Cu(acac) 3 and [Cu(hfac),] adducts [Cu(tfac),5 and [Cu(hfac),] with Bu'NO [Cu(octamethylpyrophosphoramide),l (CIo4)2 Cu" complexes of 3,6-dioxaoctane-1,8diamine-NNN'N'-tetra-acetic acid Cu,MX4 (M = V. Nb, or Ta; X = S or Se) [CU ,(S,CNEt,),] Cu" chelates of monothio-P-diketonates and diet hyldithiocarbamate [Cu 2( t tyro sin ate),] Cu" complexes of NN-dialkylated amino-acids Cu" complexes of L-dopa and related ligands Cu" amino-acid complexes Cu"-N-salicylidene-glycinecomplex [CuCl,(guanine)H,O], [Cu( N-Pr"salen),] [CuBr(N-Etsalen)], [CuCl(N-Etsalen)], [CuCl(N-Mesalen)],

e e, e.s.r., i.r.

P

e.s.r.

r

i.r., e mag e.s.r., mag, e

s, t

e, e.s.r. e.s.r.

W

U V

X

J*

1

1

4

Z

aa

ex.

bb

1.r.

CC

i.r., e.s.r., mag, e mag, e.s.r., e e.s.r.

dd ee

e, e.s.r. thermochem

99 hh

e.s.r. e.s.r. n.m.r. e

jj

e.s.r.

mm

i.r., R

nn

mag em.

00

e.s.r., mag e

44 rr

e.s.r.

ss

e.s.r., e POI e.s.r. e.s.r., e

ff

21

kk 11

PP

tt uu

uu ww xx

33 1

Elements of the First Transitional Period Complex

Physicochemical method

Re&

[(N-Hydroxyphthalimido)Cu(OAc)] [Cu(6-aminohexanoic acid),](ClO,), [(2-Diethylaminoethanolato)CuX] (X = C1, Br, or NCS) [Cu(acetylhydrazine),1C1,

mag e.s.r., e e.s.r., mag

YY

zz aaa

i.r.

hhh

(a) A. Chretien and M. Samoue, Monatsh., 1972, 103, 17; (b) D. M. Adams and D. C. Newton, J. Chem. SOC. ( A ) , 1971, 3499; (c) D. M. Adams and D. C. Newton, J. Chem. SOC. (A), 1971, 3507; (d)J. A. Barnes, G. W. Inman, and W. E. Hatfield, Znorg. Chem., 1971, 10, 1725; (e) K. C. Patil and E. A. Secco, Canad. J. Chem., 1972,50,567; v) A. B. P. Lever, E. Mantovani, and J. Donini, Inorg. Chem., 1971,10,2424; (g) H. P. Jensen and E. Larsen, Acta Chem. Scand., 1971,25,1439; (h) R. Uggla, M. Klinga, and I. Kalkka, Suomen Kem., 1971, 44, 253; (9 R. Nisasen, E. Luukkonen, and U. Karkkainen, Suomen Kem., 1971,44,404; Q) M. J. Bew, B. J. Hathaway, and R. J. Fereday, J.C.S. Dalton, 1972, 1229; ( k ) R. H. Nuttall, A. F. Cameron, and D. W. Taylor, J. Chem. SOC.( A ) , 1971, 3103; (l)J. A. Barnes, D. J. Hodgson, and W. E. Hatfield, Inorg. Chem., 1972,11,144; (m) F. A. Walker, and H. Sigel, Znorg. Chem., 1972, 11, 1162; (n) R. J. Dudley, B. J. Hathaway, and P. G. Hodgson, J.C.S. Dalton, 1972, 882; (0)R. Barbucci, L. Fabrizzi, and P. Paoletti, J.C.S. Dalton, 1972, 745; L. Fabrizzi, R. Barbucci, and P. Paoletti, ibid., p. 1529; (p) D. J. Royer, V. H. Schievelbein, A. R. Kalyanaraman, and J. A. Bertrand, Inorg. Chim. Acta, 1972, 6, 307; (4)Y. Murakami, Y.Matsudo, and K. Sakato, Znorg. Chem., 1971,10, 1728, 1734; (r) S. G . Carr, P. D. W. Boyd, and T. D. Smith, J.C.S. Dalton, 1972, 1491; (s)A. M. Heyns, J. Mol. Structure,1972, 11, 93; (t) L. Dubicki, Austral. J. Chem., 1972,25, 1141; (u) R. W. Jotham, S. F. A. Kettle, and J. A. Marks, J.C.S. Dalton, 1972,428; (v) R. Uggla and M. Melnik, Suomen Kem., 1972, 45, 16; M. Melnik ibid., 1971, 44, 255, 341 ; M. Melnik and A.-M. Taiminen, ibid., 1971,44,8; M. Melnik, R. Nasanen, and I. J. Seppala, ibid., 1971, 44,74; M. Melnik, Acta Chem. Scand., 1971,25,3777; (w)R. J. Fereday and B. J. Hathaway, J. Chem. SOC. ( A ) , 1971, 2758; ( x ) K. Dawson, M. A. Hitchman, D. K. Prout, and F. J. C. Rossotii, J.C.S. Dalton, 1972, 1509; (y) M. Melnik and R. Uggla, Suomen Kem., 1971,44,315; (2) R. Uggla and M. Melnik, Acta Chem. Scand., 1971, 25, 1790; (aa) M. Melnik, Acta Chem. Scand., 1972, 26, 697; M. Melnik and R. Uggla, Suomen Kem., 1971,44,5; M. Melnik, ibid., p. 175; (bb)N. D. Chasteen, Inorg. Chem., 1971,10,2339; (cc) D. N. Sathanarayana and V. V. Savant, Z. anorg. Chem., 1971,385,329; (dd) J. Kratsmar-Smogrovic, J. Sokolik, N. Zrubakova, and S. Surka, Z. Naturforsch., 1971, 26b, 1365; (ee) R. A. Zelonka and M. C. Baird, Inorg. Chem., 1972, 11, 134; M. Melnik and R. Uggla, Suomen Kem., 1971, 44, 95; M. Melnik, p. 97; Cff) A. D. Toy, T. D. Smith, and J. R. Pilbrow, J. Chem. SOC.( A ) , 1971, 2925; (gg) R. A. Palmer, C. G. Roy, and R. C. Roy, J. Chem. SOC.( A ) , 1971,3084;(hh) B. Rao and H. B. Mather, J. Znorg. Nuclear Chem., 1971,33,2919; (ii) M. D. Wisniewski and B. B. Wayland, J. Chem. SOC.( A ) , 1971, 2727; (,y) B. B. Wayland and B. B. Wisniewski, Chem. Comm., 1971,1025; (kk) R. A. Zelonka and M. C. Baird, J. Amer. Chem. SOC.,1971,93,6066; (I f) R. A. Palmer and C. R. Taylor, Znorg. Chem., 1971, 10, 2546; (mm) S. G . Carr, P. D. W. Boyd, and T. D. Smith, J.C.S. Dalton, 1972,907; (nn) K. H. Schmidt, A. Muller, J. Bonwma, and F. Jellinek, J. Mol. Structure, 1971, 11, 275; (00)J. F. Villa and W. E. Hatfield, Znorg. Chem., 1971, 10, 2038; (pp) A. D. Toy, S. H. H. Chaston, J. R. Pilbrow, and T. D. Smith, Znorg. Chem., 1971, 10, 2219; (qq) J. F. Villa and W. E. Hatfield, Inorg. Chem., 1972, 11, 1331; (rr) C. P. Nash and C. A. Jacks, J. Amer. Chem. SOC., 1972, 94, 1767; (ss) S. G. Carr, T. D. Smith, and J. R. Pilbrow, J. Chem. SOC. ( A ) ,l971,2569;(tt)W. Lohmann,Z. Naturforsch., 1971,26b, 1098; V. A. DavankovandP. R. Mitchell, J.C.S. Dalton, 1972,1012; (uu) R. P. Singh and A. A. Khan, J. Inorg. Nuclear Chem., 1972,34,1663; (vu) J. F. Villa, Inorg. Nuclear Chem. Letters, 1972, 8, 577; (ww)R. J. Dudley, R. J. Fereday, B. J. Hathaway, and P. G. Hodgson, J.C.S. Dalton, 1972, 1341; (xx) E. Sinn and W. T. Robinson, J.C.S. Chem. Comm., 1972, 359; (yy) H. G. Biedermann, P. K. Burkert, K. E. Schwarzhaus, and K. Wlchmann, Z. Naturforsch., 1971,26b, 734; ( z z ) R. J. Dudley, B. J. Hathaway, and P. G. Hohgson, J. Chem. SOC.( A ) , 1971, 3355; C. D. Gamer, P. Lambert, F. E. Mabbs, and J. K. Porter, J.C.S. Dalton, 1972, 320; (aaa) M. Lehtonen, E. Luukkonen, and R. Uggla, Suomen Kem., 1971, 44, 399; (bbb) Y. Y. Kharitonov and R. I. Machkhoshvili, Russ.J. Inorg. Chem., 1971, 16, 847.

Hathawaygo4has attempted to assess the value of the electronic properties of polycrystalline mononuclear copper complexes with the [CuN4], [CuN,]. and [CuN,] chromophores of unknown crystal structure, in predicting the stereochemical environment of the copper@) atom. The value of having 904

B. J. Hathaway, J.C.S. Dalton, 1972, 1196.


332

complementary data such as the magnetic susceptibility and e.s.r. and electronic spectra is emphasized in order that a reliable prediction be made. He concludes that ‘from a polycrystalline sample of copper(I1)complex of unknown structure, under favourable circumstances of arrangement of molecules in the unit cell and with a knowledge of the room temperature magnetic moment, and the e.s.r., i.r., and electronic reflectance spectra, it should be possible to make a tentative prediction of (a) the approximate copper(1r) stereochemistry and (b) for axial systems, the degree of tetragonal distortion.’ CNDO-MO calculations have been performed for the square-planar copper(I1) complexes, CuL, (L = dmg, acac, or salen), [Cu(porphin)I2+, [Cu(ox),]’-, and [ C U ( C N ) ~- ] and ~ for the distorted octahedral complexes [CuL2X2] (L = acac or salen, X = H,O or NH,). Covalency in the resulting d-orbitals correlates extremely well with values derived from e.s.r. data; however, the calculations give transferred spin densities to the ligands which are approximately half the size of those obtained from the superhyperfine couplings in the e.s.r. spectra.’05 The relative d-orbital energies of copper(I1)in tetragonaloctahedral and square-pyramidal stereochemistries have been calculated by the point-charge method and have been compared with experimental data.906 Crystallographic data for copper(I1)complexes are reported in Table 6.

Table 6 Structural studies ( X - r a y ) on copper complexes Complex [Cr(NH3

161 [cuBr 5 1

[WNH,),] [CuCl,Br,]

Comments Regular trigonal-bipyramidal anion Random disorder of Br and CI between axial and equatorial sites Square-planar anion Flattened tetrahedral anion

(NH,CH,CH,NH,)CuCl, 3-(2-Diethylammoniumethoxy)-1,2-benzisothiazole CUCl, Distorted tetrahedral anion [Me,NH,],CuC1, MOO, in fairly regular tetrahedra CuO, CU,-~MO,O,,(X= 0.15) octahedra and CuO, square-pyramids with one more distant oxygen completing a deformed triangular prism Wurtzite structure

Ref. a a

b C

d

e

f 9

[Cu(en), NCSICIO,

905

’06

Cu in tetragonal-pyramidal array with basal plane consisting of 2NH, and bidentate CO,. Axial 0 is from carbonate of an h adjacent formula unit Polymeric with 4 equatorial N atoms from en and 2NCS. 2 axial positions occupied by S atoms of NCS bridges giving Octahedral co-ordination. i N-bonding thiocyanate bridged via N atom only to adjacent cations giving octahedral co-ordination j

D. W. Clack and M. S. Farrimond, J.C.S. Dalton, 1972, 29. R . J . Fereday, J . Chem. SOC.( A ) , 1971, 3035.


Comments

[Cu(hfac),( NN-Me,en),]

Two chelating diamine ligands. One of the 2 hfac groups forms long Cu-0 bonds in axial positions Tetragonal co-ordination with 2 chelating pn ligands and S-bonded NCS groups Centrosymmetric dimer. Each Cu surrounded by 7 atoms. Asymmetric bidentate NO, co-ordination Both have exactly trans planar co-ordinat ion Both 6-co-ordinate with asymmetric NO, groups. Both forms have grossly similar structures Infinite chain of cations with bridging C10, groups. Tetragonal co-ordination Trigonal-bipyramidal with bipy-N atoms in equatorial plane Terdentate ligands give distorted octahedral co-ordination Square-planar Square-planar complex. Degradation product from adenine N1-oxide (see Vol 1, p. 253) Two forms are conformational isomers. Both have distorted trigonal-bipyramidal co-ordination trans planar 0 and N atoms with unidentate OAc groups. Distorted octahedral co-ordination completed by bridging H,O molecules Preparation and structural data. Distorted square-pyramidal Cu atoms with 2 bridging carboxylate and hydroxy-groups. Other carboxylate unidentate. No Cu . . . . Cu interaction trans a-pic. molecules. Tetragonal co-ordination with axial 0 atoms Distorted square-pyramidal with unidentate carboxylate groups. Monomeric Dimeric with bridging carboxylates CU. . . . CU = 2.565 A Octahedral with axial unidentate carboxylate groups. 2 imidazole groups have displacement of protons Me compound has trans py molecuies and chelating carboxylates ( N . B . Cu-OMe = 2.36 A). Ph compound is square-pyramidal with H,O at apex, trans py molecules and unidentate carboxylates in basal plane rneso-ligands form 2 chelate rings which link

[Cu(2,3-Me,py),X,] (X = Clor Br) [Cu(a-picoline),(NO,),] (2 forms)

[Cu(terPY),l(NO,), [( H-pyrrole-2-aldimine),Cu]

[(4-Aminoimidazole-5carboxamidoxirne),Cu]

c10,

[{ 1,7-Bis-(2-pyridyl)-2,6-

diazaheptane}Cu(NCS)] CNS (2 forms) [Cu(OAc),(p-toluidene),(H,O)J

[Cu(0,CCH2CH,Me),] [(MeOCH,C02)2Cu(imidazole),] [(ROCH,CO,),Cu(py),(H20)"I

Cu(rneso-tartrate),3H2O

333 R eJ:

k 1

m n

0

P 4 r S

t

U

0

W

X

Y z

aa

bb

334


Complex

Comments

distorted octahedral Cu ions; polymeric. d-Compound dimeric, Cu surrounded by 2 cis chelating tartrates, one H,O molecule and a carboxyl0 atom of a second dimer (A) has [CU(H,O)~]~"+ chains forming Copper(r1) hydrogen maleate,4H20(A) Copperdistorted octahedral co-ordination. (B) is square-pyramidal with chelating (n)rnaleate,H,O (B) maleate, H,O and 2 0 atoms from other maleate groups Four planar N atoms and 2 axial unidentate carboxylate groups make up the co-ordination sphere. Two types of Cu atoms both with octahedral Copper( I I )phtha1ate.H ,O co-ordination. Each Cu bound to 4 phthalate and 2 H,O molecules. Polymeric Polymeric with distorted square-pyramidal Cu co-ordination and bridging oxalates 0-bridged dimer. Each Cu is squarepyramidal. Not isostructural with C1-compound Dimeric with 2 bridging pyNO ligands. Five-co-ordinate Cu atoms. Not isostructural with C1-compound CUCI,(H ,2(4-N02pyNO) trans planar CuCl,(H,O), co-ordination, one amine-oxide molecule loosely bonded in axial position (Cu-0 = 2.635 A) Dimeric. Contains 2 independent 0bridged dimers, [(4-PhpyNO)CuC12], (4 co-ord Cu, one bridge) [(6PhpyNO)CuCI,H,O], (5-co-ord Cu with apical H,O and 2 bridges) Elongated tetrahedral co-ordination Tetragonally distorted anion Six-co-ordinate octahedral Cu Dimeric with 2 unidentate and 2 0-bridged ligands. Tetragonal-pyramidal Cu atoms. Preps given Tetrahedron of Cu atoms. Chelating ligand with one S of each ligand bridging 2 Cu atoms Ligand terdentate. Tetragonal polymer [py-2,6(C02)2Cu(H,0)2] with bridging 0 atoms Dimeric with 0-bridges. Distorted [(Et ,N.CH,CH,O)CuBr] square-planar co-ordination Tetragonally distorted Cu. Closely Cu(L-phenylalinate)2 resembles Cu(L-alinate), [Cu(violurate),]. 4H,O Distorted octahedral Cu with almost planar anions bonded via oxime N atom, and ketonic 0 atoms N(1-Methyl-3-oxobutylidene)- Prepared from reaction of Cu(acacen) with N'-( 1-methyl-2-nitroso-3NO. Planar co-ordination oxobu ty1idene)ethylenediaminecopper(I1)

Ref:

Cu(d-tartrate),3H20

CC

dd ee

ff 99

hh ii

jj

kk 11 mm nn 00

PP 44

rr ss

tt

uu


Comments

Distorted trigonal-bipyramidal with 8-N of one ligand not co-ordinated 4 Cu atoms in an almost square plane. Schiff bases co-ordinated to 3 different Cu atoms. Distorted square-pyramidal co-ordinat ion Isomorphous with Ni and Cu analogues [Cu(N-But-salen)] TNT CCu,(~l,-OH)(~u,-SO,)(~-PY-Triangle of Cu atoms with triply bridging 2-~arbaldehydeoximate),], OH and SO, groups. Oximate ligands chelate to one Cu and bridge to another 16.3H20 [Cu(N-fl-Me,aminoethylsalicylaldimine),] [Cu( H20)(N-(2-py)salen}],(NO,),

335 R eJ VV

ww xx

YY

(a) S. A. Goldfield and K. N. Raymond, Inorg. Chem., 1971, 10, 2604; (b) G. Birrell and B. Zaslow, J. Znorg. Nuclear Chem., 1972, 34, 1751; (c) A. C. Bonamartinio, M. Nardelli, C. Palrneri, and C. Pelizzi, Acta Cryst., 1971, B27, 1775; (d) R. D. Willett and M. L. Larsen, Znorg. Chim. Acta, 1971, 5, 175; (e) L. Katz, A. Kasenally, and L. Kihlborg, Acta Cryst., 1971, B27,2071; (f) G. Chapins and A. Niggli, Acfa Crysf., 1972, B28, 1626; (g) A. Muller and W. Sievert, Z. Naturforsch., 1972, 27b, 722; (h) M. H. Meyer, P. Singh, W. E. Hatfield, and D. J. Hodgson, Acta Cryst., 1972, B28, 1607; (11J.

Garaj, M.Dunaj-Jurco, and 0. Lindgren, Coll. Czech. Chem. Comm., 1971,36,3863; 0)M.Cannas, G. Carta, and G. Marongui, Chem. Comm., 1971, 1462; ( k )M. A. Bush and D. E. Fenton, J. Chem. SOC. (A), 1971, 2446; (0 G. D. Andreetti, L. Cavalca, and P. Sgarabotti, Gazzetta, 1971,101,483; (m)A. F. Cameron, K. P. Forrest, D. W. Taylor, and R. H. Nuttall, J. Chem. SOC.( A ) , 1971,2492; (n)W. Stahlin and H. R. Oswald, Acta Cryst., 1971, B27, 1368; (0)A. F. Cameron, D. W.Taylor,and R. H. Nuttall, J.C.S. Dalton, 1972,58;@) H. Nakai, Bull. Chem. SOC.Japan, 1972,44,2412;(q) F. S. Stephens, J.C.S. Dalton, 1972, 1350; ( r ) M.Matthew and G. J. Palenik, J. Coord. Chem., 1971, 1, 243; (s) R. Tewari and R. C. Srivastava, Acta Cryst., 1971, B27, 1644; ( t ) C . D. Stout, M. Sundaralingam, and G. H.-Y. Lin, Acza Cryst., 1972, B28, 2136; (u) N. A. Bailey and E. D. McKenzie,J.C.S. Dalton, 1972, 1566; (v) R. C. Komson, A. T. McPhail, F. E. Mabbs, and J. K. Potter, J. Chem. SOC.( A ) , 1971, 3447; (w)R. G. Little, D. B. W. Yawney, and R. J. Doedens, J.C.S. Chem. Comm., 1972,228; (x) G. Davey and F. S. Stephens, J. Chem. SOC. ( A ) , 1971,2577; 0)C. V. Goebel and R. J. Doedens, Inorg. Chem., 1971, 10, 2607; (z) M. J. Baird and T. R. Lomer, Acta Cryst., 1972, B28, 242; (an) C. K. Prout, G. B. Allinson, and F. J. C . Rossotti, J. Chem. SOC.( A ) , 1971,3331; (bb) C. K. Prout, M. J. Barrow, and F. J. C. Rossotti, J. Chem. SOC.( A ) , 1971, 3326; (cc) C. K. Prout, J. R. Carruthers, and F. J. C. Rossotti, J. Chem. Sac. ( A ) , 1971, 3336; (ddj C. K. Prout, J. R. Carruthers, and F. J. C. Rossotti, J. Chem. SOC. ( A ) , 1971, 3342; (ee) R. Uggla and M. Klinga, Suomen Kem., 1972,45, 10; (f,’, C. K. Prout, J. R. Carruthers, and F. J. t.Rossotti, J . Chem. SOC.(A), 1971, 3350: (gg) L. Cavalca, A. Chiesi-Villa,A. Manfredotti, A. Mangia, and A. A. G. Tomlinson, J.C.S. Dalton, 1972,391;(hh)J. E. Whinnery and W. H. Watson, J. Coord. Chem., 1972,1,207; (iij A. D. Mighell, C. W. Reimann, and A. Santoro, Acta Cryst., 1972, B28, 126; b)R. J. Williams, D. T. Cromer, and W. H. Watson, Acta Cryst., 1971, B27, 1619; (kk) W. H. Watson and D. R. Johnson, J. Coord. Chem., 1971, 1, 145; (10 J. A. Bertrand and A. R. Kalyanaraman, Inorg. Chim. Acta, 1971,5,341; (mm) M. R. Truter and B. L. Vickery, J.C.S. Dalton, 1972, 395; (nn) P. M. Laugt, J. C. Guitel, I. Tordjrnan, and G. Bassi, Acta Cryst., 1972, B28, 201; (00) J. N. Brown, J. R. Eichelberger, E. Schaeffer, M. L. Good, and L. M. Trefonas, J. Amer. Chem. Soc., 1971,93,6290; (pp) S. L. Lawton, W. J. Rohrbaugh, and G. T. Kokotailo, Inorg. Chem., 1972, 11, 612; (qq) M. Bianci-Cingi, A. Chiesi-Villa, G. Guastini, and M. Nardelli, Gazzetta, 1971, 101, 825; (rr) A. Pajunen and M. Lehtonen, Suomen Kem., 1971, 44,200; (8s) D. Van Der Hlem, M. B. Lawson, and E. L. Enwall, Acta Cryst., 1971, B27,2411; (tt) M. Hamelin, Acra Crysf., 1972, B28, 228; (uu) M. B. Cingi, A. Chiesi-Villa, A. G. Manfredotti, C. Guastini, and M. Nardelli, Acta Cryst., 1972, B28, 1075; (vv) P. C. Chieh and G. J. Palenik, Inorg. Chem., 1972,11, 816; ( w w ) J. Drummond and J. S. Wood, J.C.S. Dalton, 1972, 365; (xx) E. E. Castellano, 0. J. R. Hodder, C. K. Prout, and P. J. Sadler, J. Chem. SOC.( A ) , 1971, 2620; b y ) R. Beckett and B. F. Hoskins, J.C.S. Dalton, 1972, 291.

7 Ligands Several reports have appeared of the use of metal complexes as ligands in co-ordination compounds. Thus, [(X-C~)~M(SR),] (M = Mo or W; R = Me, Et, or Bun) act as ligands towards cobalt(r1) and iron@). When anhydrous


336

COX, or FeCl, is treated with the molybdenum or tungsten complexes in ethanol or THF, the tetrahedral complexes [(n-Cp),M'(SR),M2X2] (M2 = Co, X = C1. Br, I, or SCN: M' = Mo or W; M2 = Fe, X = C1, M' = Mo or W) are formed.907 The structure of [(n-Cp),Mo(SBun),FeC12] has been reported and there is no Mo . . . Fe bonding.'08 The complex cations [(n-Cp),M'(SR),M2(SR),M1(x-Cp)2]2+(M' = Mo, W; M 2= Ni, Pd, or Pt) have been previously reported and are thought to involve square-planar co-ordination of M2. The reaction of the corresponding d' complex [(n-Cp),Nb(SMe),] with d8 metals has now been examined and the structure of the nickel complex elucidated. [((x-Cp),Nb(SMe),} 2Ni]Z+ is prepared by first treating [ ( ~ - C P ) ~ Nb(SMe),] with iodine and then treating the resulting [(n-Cp),Nb(SMe),]I with NiCI,. The cation was isolated as its PF; salt, and structural studies showed the [NiS,] core to be of almost exact D Z d symmetry. The complex is diamagnetic and the tetrahedral nickel atom is therefore formally regarded as zero-valent. There appears to be substantial Nb-Ni bonding and this may be represented as donor bonds from the nickel atom to the do niobium atoms. It is believed that the bonding and the stereochemistry are of the same type in the Pd and Pt Complexes, and thus these complexes represent the first examples of Ni', Pd', and Pto complexes stabilized by S-donor ligands: it is proposed that this arises as a result of the presence of Ni-Nb bonds, which are of essentially (3 symmetry.909 Photochemical reactions of [(1,7-BgHgCHE),Fe]2- (E = P or As) with and it M(CO), (M = Cr, Mo, or W) give [{1,7-BgH,CHE-M(CO),),Fe]2is proposed that each heteroatom carbaborane is x-bonded and o-bonded to M.910 The structure of [{ ferrocene-1,l'-bis(dimethylarsine)}Ni(CO)12] has been reported. The nickel atom has trigonal-bipyramidal geometry with one axial and one equatorial arsenic atom. The carbonyl group is the other axial ligand.g The complexes [Ni( NP,)X]X [NP, = tris-(2-phenylphosphinoethyl)-amine; X = C1, Br. or I] react with MX, (M = Fe, Co, Ni, or Zn) to give [NiM(NP,)X,]. Spectral and magnetic studies suggest that these complexes have dinuclear non-ionic structures based on square-planar [NiNP2X] and pseudo-tetrahedral [MPX,] cores.912Thecomplexcation,[Co{Ph,P(CH2)2PPh,},(CN)~]+ acts as a positively charged ligand ( L + )giving a range of complexes [M(L+)X,] (M = Mn, Fe, Co, Ni, or Zn; X = halogen or NCS). These are postulated as being pseudo-tetrahedral zwitterion complexes in which Co"' is bound to the A series of dinuclear MX, group by the nitrogen atom of a cyanide complexes has been formed using planar M(qsb) (qsb = a quadridentate Schiff base) as ligands. The complexes [M'(qsb)M2C1,] (M'= Cu or Ni, M2 = Mn

''

A. R. Diasand M. L. H. Green, J . Chem. Suc. ( A ) , 1971. 2807. T. S. Cameron and C. K. Prout, Acra Crysr., 1972, 828,453. 9 0 9 W . E. Douglas, M . L. H . Green, C. K . Prout, and G. V. Rees,Chem. Comm., 1971, 896. 9 1 0 D. C. Beer and L. J. Todd, J . Organometallic Chem., 1972, 36, 77. 9 1 1 C. G . Pierpont and R . Eisenberg, Znorg. Chem., 1972, 11,828. 9 1 2 M. Bacci, R. Morassi, and L. Sacconi,J. Chern. Suc. ( A ) ,1971,3686. 9 1 3 R . Rigo, B. Longato, and G. Favero, inorg. Chem., 1972, 11, 300. 907

908


337

or Cu, n = 2; M I = Cu or Ni, M 2 = Fe, n = 3) have been isolated and the effect of substituents on the qsb molecule has been examined.914 A second interesting area, now receiving increasing attention, is that of metal complexes with free-radical ligands. In the case of the 2,2-diphenyl-1picrylhydrazyl radical (dpph), reactions with CuC1, CuCl,, [Cu(acac),], and [Cu(N-Mesalen),] have been studied. In all cases, only copper(1) complexes are formed, the radical behaving as an electron-donor ligand and reducing all theCu"speciesexamined.Thestoicheiometryofthecomp1exes was [(dpph)Cu'X] (X = C1, acac, or N-Me~alen).~'Calorimetric measurements have been made on the interaction of the free-radical base, 2,2,6,6-tetramethylpiperidine-N-oxyl, with [Cu(hfac),]. The 1 :1 adduct was isolated, and magnetic data indicate a large intramolecular antiferromagnetic coupling; various mechanisms of spin-spin interaction have been considered to explain this magnetic behaviour. A comparison of observed and calculated enthalpies of formation allowed the contribution to the stability from spin-spin interaction to be e~timated."~ Co", Ni", Cu", and Zn" complexes of the free-radical 2,2,6,6-tetramethylpiperidine-1 -oxyl-4-(N-salicylaldimine) (202) and Ni", Cu", and Zn" complexes of 2,2,6,6-tetramethylpiperidone(4)- 1-oxyl-thiosemicarbazone(203) have been

reported. In contrast to the results of the previous paper, there was no interaction between the metal ions and the unpaired electron of either ligand, although some complexes did show a temperat ure-dependen t interaction between the radical nitroxyl groups of the ligands.'17 The e.s.r. spectra of (202; M = Co", Ni", or Zn", n = 2; M = Co'II, n = 3) have been reported.918 The electronic spectral and magnetic data for [Co(dtbno),Br,] (dtbno = di-t-butylnitroxide) have been previously reported, but are inconsistent. Thus a typical tetrahedral spectrum was observed but the magnetic moment was reported as 2.8 BM. A re-determination of the magnetic moment shows it to be 4.23 BM at 298 K in the solid state and -4.0 BM in benzene or chloro914

'15 916

917 918

Y

S . Kokot, C. M. Harris, and E. Sinn, Austral. J . Chem., 1972, 25, 45. F. Leh and J. K. S. Wan, Canad. J . Chem., 1972, 50, 999. Y. Y. Lim and R. S. Drago, Inorg. Chem., 1972, 11, 1334. D. Jahr, K. E. Schwarzhous, D. Nothe, and P. K. Burkert, Z . Naturforsch., 1971, X b , 1210. G. R. Eaton, Inorg. Nuclear Chem. Letters, 1972, 8, 647.


338

form." Solutions of paramagnetic [Cu(tfac),] or [Cu(hfac),] in liquid dtbno exhibit 19F n.m.r. spectra. Spin-relaxation of the copper complexes is achieved by co-ordination of dtbno and rapid electron-exchange between solute and solvent. The dark-green labile adduct [Cu(hfac),(dtbno)] was isolated and characterized (peff= 1.05 BM).920 Stereochemical control in the choice of donor atoms in complexes of bifunctional bidentate ligands has been studied for complexes of the ligands ppn (204)

and ppn' (205). Both ligands act only in a bidentate fashion, ppn showing both PP and P N donation whereas ppn' shows only PP co-ordination. The choice of donor atoms is interpreted in terms of chelate ring sizes and stereochemical preferences of the metal ion in question.All the complexes with P N co-ordination studied were tetrahedral and all PP co-ordination complexes studied were planar. (Metal ions examined: Fe", Co", Ni", Pd", Zn", Cd", Hg".) The results indicate that where geometric restrictions of the ligand are absent, the preferred donor atoms are phosphorus in all cases, independent of metal ion and stereochemist ry .9 The ligand fluoro-[6,6',6"-phosphinidyne-tris-(cr-picolinaldehydeoximato)(3 -)]borate (1 +) was designed specifically to force trigonal prismatic coordination and indeed the cation [{FB(ON * CH * C,H3N)3P)Ni]+ shows almost an ideal trigonal-prismatic' structure. The structure of the analogous shows a disiron@) compound [{ FB(0N * CH C,H,N),P)Fe]BF,,CH,C12 tortion of ca. 21.5" from a true trigonal prism, and this is interpreted as a result of the balance between the forcing trigonal-prismatic nature of the ligand and the preference of low-spin Fe" for octahedral geometry.923 Co*' and Co"' complexes of the dianionic cage ligand 1,8-bis(fluoroboro)-2,7,9,14,15,20-

'

hexaoxo-3,6,10,13,16,19-hexa-aza-4,5,11,12,17,18-hexamethy1bicyclo-[6,6,6] eicosahex-3,5,10,12,16,18-ene have been studied by crystallography. The

[CON,] core in the cobalt(m)compound is slightly distorted from D , symmetry and is midway between trigonal-prismatic and octahedral geometry, whereas the cobalt(i1r) complex shows only slight distortion from trigonal-prismatic ~o-ordination.'~~ 919 920 921

922

923

924

D . G. Brown, T. Maier, and R. S. Drago, Znorg. Chem., 1971, 10,2804. R. A. Zelonka and M. C. Baird, J . Amer. Chem. SOC., 1971,93,6066. M. Randic and M . Vucelic, J . Chem. SOC. ( A ) , 1971, 3309. W. V. Dahlhoff, T. R. Dick, G . H. Ford, W. S. J . Kelly, and S. M. Nelson, J . Chem. SOC.( A ) , 1971, 3495. M. R. Churchill and A. H . Reis, Chem. Comm., 1971, 1307; J. E. Parks, B. E. Wagner, and R. H. Holm, Znorg. Chem., 1971, 10, 2472. G . A. Zakrzewski, C. A. Ghilardi, and E. C. Lingafelter, J . Amer. Chem. Soc., 1971, 93, 4411.


339

Experimentally based intuitive arguments have been presented to arrive at a regional rule for optical activity of d-d transitions of conformational isomers of octahedral metal complexes.9z5Conformational preferences for chelate rings formed by 1,3-pn in its octahedral mono, bis, and tris metal complexes have been studied by calculation of the conformational energies. In all cases, the chair conformation was found to be the most stable. The lowest energy pathway for converting from one chair configuration into another has a barrier to activation of about 7 kcal mol- 1 . 9 2 6 Conformational types of metal-edta complexes have been studied.927 A new route to optically active amino-acids has been achieved by treatment of halogen compounds with Feo or Nio diastereoisomeric complexes of a-meth ylbenzyliminogly oxylic acid ethyl ester. The geometries of possible polytertiary phosphine networks containing tervalent phosphorus atoms and bridging groups have been shown to be completely analogous to the geometries of acyclic planar networks linked by spz carbon atoms. The bridging groups between pairs of phosphorus atoms may be classified as follows, based on the co-ordinating properties of- the phosphine: (i) bridges which allow the two bridged phosphorus atoms to bond in a bidentate manner but not to span two metal atoms: (ii) bridges which allow bridging but not bidentate co-ordination: (iii) bridges which allow either bridging or bidentate co-ordination. These factors have been discussed for a . ~ ~ ~ methods have been reported for the preparation range of p h ~ s p h i n e sGeneral of (o-Ph,L1C6H4)(o-Ph2L2c6H4)Lz and (o-Ph,LzC6H4),(o-Ph2L1C6H4)L2 (I,', L2 = P, As): (o-Ph2AsC6H,),(o-Ph,Pc6H4)P has been considered in more There are no previous reports of an NOz group co-ordinating in two ways in a monomeric complex. However, the complexes [M(NO,),(edm)] (M = Co, Ni, or Cu; edm = NN'-ethylenedimorpholine) have now been reported and the cobalt and nickel complexes are six-co-ordinate with two bidentate NO, groups. However, the copper complex (peff.= 1.95 BM) contains both bidentate and .moqodentate NO, groups and chelating edm. A square-pyramidal structure has been suggested.931 An orbital correlation diagram has been presented for linear and bent M-N-0 systems in five-co-ordinate tetragonal molecules, and the diagram can be extended to six-co-ordinate complexes with only minor modifications. From this study, it is concluded that the antibonding nature of the level to be filled under C,, symmetry, and not its composition, lead to distortion and unit, and that v(N0) is not a good guide to the linear bending of the M-N-0 B. Bosnich and J. M. Harrowfield, J. Amer. Chem. Soc., 1972, 94, 3425. J. R. Gollogly and C. J. Hawkins, Znorg. Chem., 1972, 11, 156. B. Lee, Znorg. Chem., 1972, 11, 1072. J. Y. Chenard, D. Commereuc, and Y. Chauvin, J.C.S. Chem. Comm., 1972, 750. 9 2 9 R.B. King, J . Coord. Chem., 1971, 1, 67. 930 J. W. Dawson and L. M. Venanzi, J. Chem. SOC.( A ) , 1971,2897. 931 A. L. Lott,J. Amer. Chem. SOC.,1971,93, 5313. 925 926 927


340

or bent nature of the linkage.932The N-1s binding energies of range of nitrosyl compounds containing both bent and linear NO groups have been examined. A definite correlation has been found between the binding energy and the groups have either low electron density at the NO group. Linear M-N-0 or high binding energies depending on the extent of n-back-donation from the metal and binding energies can be roughly correlated with NO stretching freq~encies.’~ Increased-valence formulae have been drawn up for some dinitrogen complexes and, in the most stable state, the bonding is considerably different from that in carbonyl complexes.934 A second paper (see Vol. 1, p. 252) has appeared suggesting, on the basis of i.r. and electronic spectral data. that the anions are co-ordinated in [Cu(py),(

~

~

~

)

~

1

.

~

3

5

8 Formation and Stability Constants Table 7

Formatiori and stability constants

Formation and stability constants are not presented in detail: however, the systems studied and the relevant references are given. Manganese(I1)

Re&

Ammonia Thiobenzoate Thioacet at e S-Methyl-isothiocarbohydrazine Benzohydroxamic acid Glycinate Schiff bases derived from salicylaldehyde and aniline and its derivatives Diacet y loximethiosemicarbazone 1-(Substituted phenylazo)-2-naphthoIs Manganese(II1) edta Diethylenetriaminepenta-acetate Nitrilotriacetate Iron( 11)

936 937 937

2,4,6-Tripyridyl-l,3,5-triazine Formate Hg(CN), with ferrocyanide Riboflavin G1ycinate Schiff bases derived from salicylaldehyde and aniline and its derivatives 1-(Substituted phenylazo)-2-naphthols Iminodiacetic acid Thiobenzoate Thioacetate 932 933 934 9’5

938

939 940 941 942 943

944 944 944 945 946 947 948

940 94 1

943 949 937 937

C. G. Pierpont and R . Eisenberg, J. Amer. Chem. SOC.,1971, 93,4905. P. Finn and W. L. Jolly, Inorg. Chem., 1972, 11, 893. R. D. Harcourt. J . Mol. Structure, 1971,8, 11. S. A. Bell, J. C. Lancaster and W. R. McWhinnie, inorg. Nuclear Chem. Letters, 1971, 7, 405.


34 1

Iron(II1)

Ref.

Formate Cannabidiolic Acid dl- and rneso-Tartaric acid Citric acid Diglycolic acid Iminodiacetic acid NN'-Ethylenediaminediacetate-~\rl\r'-diacethydroxamicacid 2,3-Dihydroxypyridine Hg(CN), with ferricyanide Cobalt[I 1) Pyridine Quinoline 5-Methyltetrazole N-(2-Hydroxy- I-naphtha1idene)anthralinicacid Nitroso-2-naphthol-3,6-disulphonate Nitroso- 1-naphthol-3,6-disulphonate CoCI, in a LiN0,-NaN0,-KNO, melt Thiobenzoate Thioacetate Morpholine-N-dithiocarbinate S-Methyl-isothiocarbohydrazide Picolinic acid Nicotinic acid amide Schiff bases derived from salicylaldehyde and aniline and its derivatives 1-(Substituted phenylazo)-2-naphthols G1ycinate Serine Threonine Alanine Phen ylalanine Tyrosine bipy and en bipy and glycinate bipy and pyrocatecholate Methyliminodiacetate and glycinate o I tryptophan (+)-, (-)-,or (i-)-1,2-Diaminocyclopentanetetra-acetate ~~-2-Amino-4-hydroxybutyric acid NN'-Et hylenediamine bis-(a-glut aric acid) cis,cis- 1,3,5-Triaminocyclohexane-NN'N"-triacetate N-P-Hydroxyet hylpropylenediamine Cobalt(II1) Ammonia Pyridine Methylamine Ethylenediamine Dimethylglyoxime Nickel (0) (CF?),P, Me(CF,),P, Et(CF,),P, Bu'(CF,),P, Et,PCF, with nickel carbonyl compounds NickelOI) 5-Methyltetrazole Acetate, propionate

946 950 95 1 952 953 953 954 955 947 956 956 957 958 9 59 959 960 937 937 961 938 962 963 941 943 940,964 964,965 964,965 966 967 967 968 968 968 969 970 971 972 973 974 975 975 915 976 977

978 957 979

342


Malondialdeh yde 2-Nitroso- 1-naphthol-5-sulphonate l-Nit roso-2-naphthol-6-sulphonate 2-Nitroso- 1-naphthol-6-sulphonate N-(2-Hydroxy-l -naphthalidene) anthranilic acid Riboflavin NiCl, and NiBr, in a LiN0,-KN0,-NaNO, melt Oxy- and thio-carboxylic acids Furan-, thiophen- . and selenophen-2-aldoxime Thiobenzoate Thioacetate S-Methyl-isothiocarbohydrazide Nicotinic acid amide Schiff bases derived from salicylaldehyde and aniline and its derivatives 1-(Substituted phenylazo)-2-naphthols Glycinate Serine Threonine Alanine Phenylalanine Tyrosine bipy and en bipy and glycinate bipy and pyrocatecholate Methyliminodiacetate and glycinate or tryptophan trien and glycinate L-dopa ~~-2-Amino-4-hydroxybutyric acid N N’-Ethylenediaminebis-(a-glut aric acid) &,cis- 1,3,5-Triaminocyclohexane-NN’N”-triacetate ~~-2,3-Diaminopropionic acid NN’-Ethylenediaminediacetate-NN‘-diacethydroxamic acid Tetraethylenepentamine-hepta-acetate Monoethanolamine Benzohydroxamic acid Copper(I1) Azide Nitrite Ethylenediamine NNN’N’-Me,en, N-Eten, N-Meen dien t rien 2,3,2-tet 3,2,3-tet Pyridine, piperidine, quinoline biPY 1,I-Dimethylbenzimidazole H,O, MeOH. EtOH, Pr’OH, Bu”0H Tetraphenylmethylenediphosphinedioxide 2,3-Dihydroxybenzoic acid d-, dl-. and meso-tartaric acid Erythro- and threo-2-methyltartaric acid Meso- and rhreo-2.3-dimethyltartaric acid

Ref: 980 98 1 981 98 1 958 948 960 982 983 937 937 938 963 94 1 943 940,964 964,965 964,965 966 967 967 968

968 968 969 984 985 971 972 973 986 954 987 988 939 989 990 99 1 991,993 992 992 992 992 994 99 5 996 997 998 999 951, loo0 1001 1001


343 R eJ

Su bstitu ted-acacH Malondialdehyde

1002

980 958 Semicarbazide, thiosemicarbazide, and selenocarbazide 1003 Diethanolamine 1004 2-Hydroxy-2,3-propanediamine 1005 edta 1006 Ethylenediaminedisuccinic acid 1006 NN’-Ethylenediaminediacetate-NN’-diacethydroxamicacid 954 ~~-2,3-Diaminopropionic acid and its methyl ester 986 973 cis& 1,3,5-Triaminocyclohexane-NN’N’-triacetate 972 NN’-Ethylenediamine-bis-(a-glutaricacid) 971 ~~-2-Amino-4-hydroxybutyric acid 1007 Nitrilotriacetate 940,964,965,1008 Glycine 964,965 Serine 964 Threonine 966,1008 Alanine 968 bipy and glycinate, en, or pyrocatecholate 969 Methyliminodiacetate and glycinate or tryptophan 1009 DOPG 1008 a-Aminobutyric acid 1008 Sarcosine 1010 NN’-Anhydrobis-(p-hydroxyethy1)biquanide 101 1 bipy and olioglycines 1012 Glycinamide and related ligands 1013 Histadine 963 Nicotinic acid amide 1014 p-Substituted acetoacetanilides 1015 5-Nitrosalicylate 1016 24 o-Acety lpheny1azo)-1,8-dihydroxynaphthalene-3,6-disulphonic acid 1017 N-Salicylideneanthranilicacid Schiff bases derived from salicylaldehyde and aniline and its derivatives 941 943 1 -(Substitutedphenylazo)-2-naphthol 939 Benzohydroxamic acid 1018 Isopropoxyacetate and isopropoxythioacetate 1019 (Methy1thio)acetate and (t-butylthioacetate) 937 Thiobenzoate and thioacetate 983 Furan-, thiophen-, and selenophen-2-aldoxime 1020 Morpholine-N-dit hiocarbamate 1021 Thienyl- and phenyl-pyridine

N-(2-Hydroxyl-2-naphthalidene)anthralinic acid

936 V.

S. Kublanovskii and V. N. Belinskii, Russ. J. Inorg. Chem., 1972, 17,68.

937

A. Ouchi, T. Takeuchi, Y. Takahashi, and M. Nakatani, Bull. Chem. SOC.Japan, 1972,45,282.

938

A. Braibanti, G. Mori, F. Dallavalle, and E. Leporati, h o r g . Chim. Acta, 1972,6, 106. Y.K.Agrawal and S.G. Tandon, J. Inorg. Nuclear Chem., 1972,34,1291. R. M. Izatt, H. D. Johnson and J. f. Christensen, J.C.S. Dalton, 1972, 1152. N. Shori, Y. Dutt, and R.P. Singh, J. Znorg. Nuclear Chem., 1972,34,2007. M. Valentova and L. Sucha, Coll. Czech. Chem. Comm., 1972, 37,22. G. C. S. Manku, R. C. Chadha, N. K. Nayar, and M. S . Sethi, J. Znorg. Nuclear Chem., 1972,34, 1091. N. G. Bogdanovich, N. I. Pechurova, L. I. Martynenko, and V. V. Piunova, Russ. J . Inorg. Chem., 1971,16, 1337. P. Legittimo, F. Pantani, and G. Ciantelli, Gazzetta, 1971, 101,465. V. I. Paramanova, V. Y. Zamanskii, and V. B. Kolychev, Russ. J . Inorg. Chem., 1972, 17, 221.

939 940 941

942 943

944

945 946

344


M. T. Beck and E. C. Porzsolt, J . Coord, Chem., 1971, 1, 57. D. T. Sawyer and R. L. McCreery, Inorg. Chem., 1972, 11, 779. 949 A. Napoli, J . Inorg. Nuclear Chem., 1972, 34, 1347. 9 5 0 R. Abu-Eittah and 2.Mobarak, J . Inorg. Nuclear Chem., 1972, 34,2283. 9 5 1 S. Ramamoorthy and P. G . Manning, J. Inorg. Nuclear Chem., 1972, 34, 1977, 1989. 9 5 2 A. S. Kereichuk, Russ. J . Inorg. Chem., 1971, 16, 1346. 9 5 3 A. Napoli, J . Inorg. Nuclear Chem., 1972,34,987. 9 5 4 R. Motekaitis, I. Murase, and A. E. Martell, J . Coord. Chem., 1971, 1, 77. 9 5 5 K. E. Curtis and G . F. Atkinson, Canad. J . Chem., 1972,50, 1649. 9 5 6 N. V. Arkhipova, A. G . Muftakhov,and K. P. Rakhimov, Russ. J . Inorg. Chem., 1971, 16,856. 9 5 7 B. Lenarcik, M. Badyorczek-Grzonka, and Z. Grzonka, Rocznicki Chem., 1971, 45,2023. 9s8 R. K. Mehta, V. C. Singhi, and R. K. Gupta, 2. Naturforsch.. 1971, 26b, 867. 9 5 9 S. A. Bajue, G. A. Taylor, and C. C. Lalor, J . Inorg. Nucelar Chem., 1972,34, 1353. 960 P. Pacak and I. Slama, Coll. Czech. Chem. Comm., 1971,36, 2988. 9 6 1 Z. Gregorowicz, G . Kwapulinska, and Z. Kilima, Roczniki Chem., 1971, 45, 1163. 9 6 2 M. Arkhipova, A. G . Muftahov, and K . R. Rakhimov, Russ. J . Inorg. Chem., 1971, 16, 1311. 9 6 3 Z. Warnke and B. Lenarcik, Roczniki Chem., 1971,45, 1390. 964 A. Gerpely. I . Nagypal. and I. Savapo, Acta Chim. Acad. Sci. Hung., 1971, 67,241. 9 6 5 A. Gergely, J. Mojzes, and Z. Kassai-Bazsa, J . Inorg. Nuclear Chem., 1972, 34, 1277. 966 A. Gergely, B. Kiraly, I. Nagypal, and J. Mojzes, Acta Chim. Acad. Sci. Hung., 1771, 67, 133. 9 6 7 A Gergely, I. Nagypal, and B. Kiraly, Acta Chim. Acad. Sci. Hung., 1971,68, 285. 968 R. Griesser and H . Sigel, Inorg. Chem., 1971, 10, 2229. 969 J. Israeli and R. Volpe, Inorg. Chim. Acta, 1972,6, 5 ; Inorg. Nztclear Chem. Letters, 1971,7, 1183. 9 7 0 N. Paulic, V. Simeon, B. Bernik, B. Suigir, and D. Fles, J. Inorg. Nuclear Chem., 1971, 33, 3463. 9 7 1 A. Braibanti. F. Dallavalle, E. Leporati, and G. Mori, Inorg. Chim.Acta, 1971, 5, 449. 9 7 2 C. P. Trivedi, 0. P. Sunar, and S. Tak, J . Inorg. Nuclear Chem., 1972, 34,907. 9 7 3 L. J. Zompa, Inorg. Chem., 1971, 10, 2647. 9 7 4 J. Kalinka and S. Petri, Roczniki Chem., 1971,4S, 1397. 9 7 5 T. I. Kozachenko, V. V. Beckmann, and V. E. Mironov, Russ. J . Inorg. Chem., 1971, 16, 1083. 976 G. Navon, R. Panipel, and D. Meyerstein, Inorg. Chim. Acfa, 1972,6, 299. 9 7 7 C. Bied-Charreton, L. Alais, and A. Gaudemer, Bull. SOC. chim. France, 1972, 861. 978 D.-K. Kang and A. B. Burg, Inorg. Chem., 1972, 11,902. 9 7 9 P. H. Tedesco, V. B. De Rumi, and J. A. Gonzalez-Quintana, J. Znorg. Nuclear Chem., 1971, 33, 3839. 980 M. M. Osman. Helv. Chim. Acta. 1972, 55, 239. 9 8 1 H. Saarinen, Suomen Kern., 1971,44,264: 0. Mkitie and H. Saarinen, ibid.,p. 180. 9 8 2 M. Aplincourt, D. Noizet, and R. Hugel, Bull. SOC.chim. France, 1972, 26. 983 L. S. Bark and D. Griffin, J . Inorg. Nuclear Chem., 1971,33, 381 1 . 984 Y. J. Israeli and R. Volpe. Bull. SOC.chim. France, 1971, 3119. 9 8 5 J. E. Gorton and R. F. Jameson, J.C.S. Dalfon, 1972, 310. 986 R. W. Hay and P. J. Morris, J . Chem. SOC.( A ) , 1971, 3562. 9 8 7 Y. Masuda. Y. Hirai, and E. Sekido, Bull. Chern. SOC. Japan, 1971,44, 2381. 9 8 8 G . A. Bhat and R. S. Subramanya, J . Inorg. Nuclear Chem., 1971,33, 3487. 9 B 9 E. F. De A. Neves and P. Senise, J . Inorg. Nuclear Chem., 1972, 34, 1915, 1923. 990 J. Tummavnori, Suomen Kem., 1971,44, 222. E. Arene, P. Paoletti, A. Dei, and A. Vacco, J.C.S. Dalton, 1972, 736; R. Barbucci, L. Fabrizzi, P. Paoletti, and A. Vacco, ibid., p. 740. 992 R. Barbucci, L. Fabrizzi, and P. Paoletti, J.C.S. Dalton, 1972, 1099. 993 J. W. Allison and R. J. Angelici, Inorg. Chem., 1971, 10, 2233. 9 9 4 A. G. Muftakhov, V. A. Alekseevskii, L. M. Naumova, and K. R. Rakhimov, Russ. J . Inorg. Chem., 1971, 16,819. 9 9 5 M. T. Falqui, Gazzetta, 1971, 101, 923. 996 M. V. Artemenko and K. F. Slyusarenko, Russ. J . Inorg. Chem., 1971, 16, 1154. 9 9 7 S. N. Andreev and A. I. Chaiko, Russ. J . Inorg. Chem., 1971, 16, 1045. 998 Z. A. Sheka, K. B. Yatsimirskii, M. A. Ablova, K. S. Yudina, T. D. Medved, and M. I. Kabachnik, Russ. J . Inorg. Chem., 1971, 16, 1301. 9 9 9 H. Harada, Bull. Chem. SOC. Japan. 1971,44, 3459. ' O o 0 M. M. Petit-Ramel and C. M. Blanc, J. Inorg. Nuclear Chem., 1972, 34, 1241. 'Ool K. Horikawa and S . Masuyama, Bull. Chem. SOC.Japan, 1971,44, 2697. ' O o 2 T. M. Shepherd, J.C.S. Dalton, 1972, 813. ' O o 3 S. 0. Ajayi and D. R. Goddard, J . Chem. SOC.( A ) , 1971, 2673. 947

948

Elements of the First Transitional Period 1004

345

S. Mahapatra and R. S. Subrahmanya, Proc. Indian Acad. Sci., 1971,73, 148. R.Nasanen and E. Lindell, Suomen Kem., 1972,45, 18. l o o 6 R. I. Gorelova, V. A. Babich, and I. P. Gorelov, Russ. J . Inorg. Chem., 1971, 16,995. ' 0 ° ' P. G. Manning and S . Ramamoorthy, Inorg. Nuclear Chem. Letters, 1972,8,653; S . Ramamoorthy, C. Guarenaschelli, and D. Fecchio, J . Znorg. Nuclear Chem., 1972, 34,1651. l o o * A. Yingst, R. M. Izatt, and J. J. Christensen, J.C.S. Dalton, 1972, 1199. l o o 9 J. E. Gorton and R. F. Jameson, J.C.S. Dalton, 1972, 307. '010 J. Krajewski and T. Lipiec, Roczniki Chem., 1971,45, 1621. '01' H . Sigel, R. Griesser, and B. Prijs, Z . Naturforsch., 1972, 27b, 353. l o i Z 0. Yamauchi, H.Miyata, and A. Nakahara, Bull. Chem. SOC.Japan, 1971,44,2716. D. R.Williams, J.C.S. Dalton, 1972, 790. H . J. Harries, R. K. Hughes, and T. Smith, J . Znorg. Nuclear Chem., 1972, 34, 1609. A. R. Das and V. S . K. Nair, J . Znorg. Nuclear Chem., 1972,34, 1271. S . Nagamori and H. Miyata, Bull. Chem. SOC.Japan, 1971,44, 3476. lol' R.K.Mehta and R. K. Gupta, Canad. J . Chem., 1972,50, 1609. '01* A. Sandell, Acta Chem. Scand., 1971, 25, 2609. A. Sandell, Acta Chem. Scand., 1971, 25, 3172; A. Ouchi, T. Takeuchi, and Y . Ohashi, Bull. Chem. SOC.Japan, 1971,44, 346 1. l o Z o Z. Gregorowicz, G. Kwapulinska, Z. Klima, and E. Ziaja, Coll. Czech. Chem. Comm., 1972, 37, 119. l o Z 1 H. Sigel, H.Wynberg, T. J. Van Bergen, and K . Kahmann, Helv. Chim. Acta, 1972, 55. 610. loo'

3 The Noble Metals BY L. A. P. KANE-MAGUIRE

1 Ruthenium Cluster Compounds.-A convenient atmospheric pressure preparation of Ru,(CO),, has been reported. The method involves bubbling CO through a refluxing solution of RuCl,, xH,O to produce Ru(CO),Cl,, followed by further treatment with ethanol and granulated zinc. The yields of up to 80% increase the availability of this useful starting material.’ Pyrolysis of solid Ru,(CO), in a sealed tube has been shown to yield the carbide Ru,C(CO),, in 5 % yield., This result confirms the previous assumption3 that the carbon is produced by reduction of a co-ordinated CO group. Contrary to the previous report, a re-investigation of the reaction of Ru,(CO),, with refluxing benzene yielded not only Ru,C(CO),,, but also small amounts of Ru,C(CO),,(C,H,). In the course of studies aimed at determining the active catalytic species in hydroformylation reactions, a new quantitative preparation of H,Ru,(CO),, has been found. Reaction of this species with phosphines yielded the new complexes [H,Ru,(CO),,-~(PR~),] (n = 1-4; R = C,H, or Ph)? The analogous derivatives [H,Ru,(CO),,- ,{P(OMe),),] (n = 1-4) have been prepared by refluxing H,Ru,(CO),, with trimethylphosphite in heptane. These orange, air-stable complexes show only terminal CO groups in their i.r. spectra. The presence of on1y.a single Ru-H shift in their ‘H n.m.r. spectra indicates intramolecular tautomerism.’ Reaction of Ru,(CO),, with PF,-CO mixtures at moderate pressure and temperature has given the substituted clusters [Ru,(CO)lz-n(PF3)n](n = 0-6). More vigorous conditions cause collapse of the cluster, and the production of the monomeric complexes [Ru(CO), -,(PF3),] (n = 3-5). Trifluorophosphine is thus more effective in replacing CO than is triphenylphosphine, which only replaces three CO groups. ,F N.m.r. studies indicate that the five-co-ordinate Ru(CO), - ,(PF,), species are stereochemically non-rigid., Similar phosphine- and arsine-substituted clusters [Ru,(CO),(AMe,CH,Ph),] (A = P or As) were obtained by refluxing Ru,(CO),, with the ligand in cy~lohexane.~ The green nitrosyl cluster [Ru,(CO),,(NO),] has been reported in 30%

,

’ ’

J. L. Dawes and J. D. Holmes, Znorg. Nuclear Chem. Letters, 1971, 7, 847. C. R. Eady, B. F. G. Johnson, and J. Lewis, J. Organometallic Chem., 1972, 37, C39. B. F. G. Johnson, R. D. Johnson, and J. Lewis, J. Chem. Soc.(A), 1968, 2865. F. Piacenti, M. Bianchi, P. Frediani, and E. Benedetti, Inorg. Chem., 1971, 10,2759. S. A. R. Knox and H. D. Kaesz, J. Amer. Chem. SOC., 1971,93,4594. C. A. Udovich and R. J. Clark, J. Organometallic Chem., 1972, 36, 355. R. L. Bennett, M. I. Bruce, and F. G.A. Stone, J . Organometallic Chem., 1972,38, 325.

347

348


yield from the reaction of NO with Ru,(CO),, in benzene. Its i.r. spectrum suggests bridging nitrosyl groups, which was confirmed from an X-ray analysis (see Table 1). 1.r. studies show that the structure is maintained in solution.’ An interesting cluster [(Cl 2H,oN,)Ru,(CO),], of proposed structure (11,

Q HN

NPh

(1)

has been isolated from the reaction of o-semidine on Ru3(CO),,. A minor product was the dimer [(C,,H,,N,)RU,(CO)~]. Related dimeric complexes were obtained using a z o b e n ~ e n e . ~ Unusual mixed cluster compounds of the type [RuPt,(CO),L:] and [Ru,Pt(CO),Li] (L’ = PPh,, PMePh,, PMe,Ph, or AsPh,; L2 = PMe,Ph) have been prepared via the addition of Ru,(CO),, to PtCl,. The structures (2)and (3) were proposed from i.r. studies. These clusters join a growing number

co of such compounds which do not obey the effective atomic number rule.” The thermal reaction between Ru,(CO),, and Mn,(CO)lo has yielded the mixed cluster [(CO),M~RU(CO),M~(CO)~].~’ Analogy with the known12 [ ( C O ) , MnFe(CO),Mn(CO),] suggests the structure (4:M = Ru). Similar mixed

co co oc co co co

\/ I/ \ / /\ /I /\ oc oc occo oc co

OC-Mn-M-Mn-CO

(4)

lo

l2

J. R. Norton, J. P. Collman, G . Dolcetti, and W. T. Robinson, Znorg. Chem., 1972, 11, 382. M. I. Bruce, M. Z. Iqbal, and F. G . A. Stone, J . Organometallic Chem., 1971, 31, 275. M. I . Bruce, G . Shaw, and F. G . A. Stone, Chem. Comm., 1971, 1288. E. W. Abel, R. A. N. McLean, and S. Moorhouse, Inorg. Nuclear Chem. Letters, 1971, 7, 587. P. A. Agron, R. D. Ellison, and H. A. Levy, Acta Cryst., 1967,23, 1079.

The Noble Metals

349

clusters have been reported from the treatment of Ru3(C0),, with the anions [M(CO),]- (M = Mn or Re) in various solvents. However, the reaction gives a complex mixture of anionic species from which only (Me,N)[ReRu,(CO),,] could be separated in pure form. Its i.r. spectrum indicated only terminal CO groups, suggesting (4a)or (4b)as possible structures. Acidification of the reaction

mixtures yielded more readily isolable neutral hydride complexes, including the new [H,R~,Ru,(CO),~],[H,Re,Ru(CO),,], and [H,Ru,(CO),,].'~" Further studies have been reported on the green 0x0-centred trimer [Ru,O(CO,Me)(H,O),]+, isolated from the reaction of acetic acid with RuCl,, xH,O. Both this complex and its tris-pyridine derivative can undergo successive one- and two-electron reductions to give compounds of ruthenium(III)(III)(rI) and ruthenium(m)(II)(II),respectively. In contrast to electrochemical reduction, [Ru,(CO,Me),(H,O),] was isolated as the second stage product in reduction with hydrogen:

However, the central oxygen can be readily re-inserted using molecular oxygen or pyridine N-oxide.', The compounds [H,Ru,(CO),X] (X = S, Se, or Te) have been obtained by treating alkaline solutions of Ru,(CO),, with chalcogen compounds, followed by acidification with sulphuric acid. Structures involving H-bridges between Ru atoms were suggested from 'H n.m.r. and i.r. spectral data. On the other hand, the polymer [Ru(CO),CS], was isolated after refluxing Ru,(CO),, with carbon di~u1phide.I~ Two related papers have appeared describing the reactions of Ru,(CO),, with Group IV donor ligands. The thermal reaction with trimethylgermane in hexane yielded a mixture of [Ru(Me,Ge),(CO),] and [(Me,Ge)Ru(CO),(p-GeMe,)],. In contrast, the major photochemical product was [Ru(Me,Ge)(C0),l2. Pyrolysis of [Ru(Me,Ge),(CO),] produced the interesting clusters [Ru,(CO),(Me,Ge),] (5) and [Ru,(Me,Ge),(CO),], both of which involve Me,Ge bridging groups.' Similarly, the thermal and photochemical reaction of Ru,(CO),, with Me,SiH gave [(Me,Si)Ru(CO),(p-SiMe,)], in 20 % yield. A more useful Knight and M. J. Mays, J . C. S. Dalton, 1972, 1022. A. Spencer and G. Wilkinson, J . C . S. Dalton, 1972, 1570. E. Sappa, 0.Gambino, and G. Cetini, J . Organometallic Chem., 1972, 35, 375. S. A. R. Knox and F. G. A. Stone, J . Chem. SOC.( A ) , 1971,2874.

l Z aJ. l3

l4 l5

350


(co)~

starting material was [(Me,M)Ru(CO),], (M = Si or Ge), which gave the dimer Ru,(Me,Si)(CO), with Me,Si,H2.’6 The similarity of the i.r. and ‘H n.m.r. spectra of the latter product to those of the known germanium analogue” suggests the structure (6). Me,

Several X-ray structural studies have been made on hydrido-ruthenium clusters (see Table 1).’8-20 Ruthenium-(0) and -(I).--Apart from the rfithenium clusters discussed separately. only a few new ruthenium(0) complexes have been reported. The isocyanide complexes [Ru(CO),(CNR)(PPh,),] and [Ru(CO)(CNR)(PPh,),] have been prepared as shown in Scheme 1. Use of oxygen in the final step gave [RuHCl(CO)(PPh,),]

+ RNC

+

[RuHCl(CO)(CNR)(PPh,),]

I

AgCIO,

[RuH(CONCNR)L(PP~,)~] [RuH(OClO,)(CO)(CNR)(PPh,),l EtOH

I

NaOH

(L = CO, PPh,)

[Ru(CO)(CNR)(PPh,),L] Scheme 1

the molecular oxygen complex [Ru(O,)(C0)(CNR)(PPh3),1.I. r. and ‘H n.m.r. studies of the reverse protonation of [Ru(CO),(CNR)(PPh,),] showed that H + attacks specifically trans to the isocyanide group.2‘ A similar preparative ‘6 ” l8

l9

*’

A. Brookes, S. A. R. Knox, and F. G. A. Stone, J. Chem. SOC. ( A / . 1971, 3469. M. Elder and D. Hall, Inorg. Chem., 1969, 8, 1424. D. B. W. Yawney and R. J. Doedens, Inorg. Chem., 1972,11, 838. C. J. Gilmore and P. Woodward, J . Chem. SOC.( A ) , 1971, 3453. 1971, 93,5670. M. R.Churchill and J Wormald. J. Amer. Chem. SOC., D. F. Christian and W. R. Roper, Chem. Comm., 1971, 1271.

35 I

The Noble Metals

route has yielded the new complex [Ru(CO),(PPh,),]. Its single v(C0) band indicates equatorial phosphines and trans CO groups.22An improved synthesis has been reported for a range of hydrido and carbonyl complexes of noble metals, including [Ru(CO),L,] [L = P(p-MeC,H,), or P(p-MeOC,I-I,),]. This method involves the use of ethanolic KOH or NEt, as the basic reducing agent under homogeneous conditions,220rather than the NaBH, previously employed.22b The brown Ru' dimer, [Ru,Cl,(Hdma)], has been imlated after bubbling hydrogen through a solution of RuC1,,3H20 in dimethylacetamide for 2 h at 85 "C.The diamagnetic complex acts as a homogeneous catalyst for the hydro, ~ interesting study has shown that the use of sterically genation of olefins e t ~ . An crowded phosphines can promote M-M bond formation. Whereas reaction of non-crowded phosphines (L) with RuCI, and CO is known to give [RuCl,(CO),L,] species, similar reactions where L = PBu',Ph or PBu',p-tolyl yielded the diamagnetic dimers [RuCl(CO),L],. An X-ray analysis of the di-t-butylp-tolylphosphine complex (see Table 1) confirmed the short Ru-Ru distance.24 Studies of the catalytic carbonylation of secondary amines by [Ru(CO),(OCOMe)], have suggested the mechanism shown in Scheme 2. The inter[Ru(CO),(OCOMe)ln+ Am

[Ru(CO),(OCOMe)Am], 3[Ru(CO),(OCOMe)Am],(n

=

+ N-formyl amine

1 or 2) Scheme 2

mediate species [Ru(CO),(OCOMe)(Am)], was isolated and characterized.' A theoretical treatment of the CO stretching vibrations of such a complex, namely [Ru(CO),(OCOMe)(py)],, indicates that the intermolecular coupling and other interactions between CO groups are principally due to dipoledipole forces.,,

Ruthenium(u).-Group VII Donors. Halide donor ligands. A study has shown that the blue complexes obtained by electrolytic reduction of H,[RuCI,H20] in acidic solution are further examples of mixed Ru"-Ru"' complexes. They were previously assumed to contain only Ru". Dimers of the type Ru,CIg2+-;)+ (n = 0,1, or 2) were separated and isolated using ion-exchange chromatography. B. E. Cavit, K. R. Grundy, and W. R. Roper, J . C . S. Chem. Comm.,1972,60. ""N. Ahmad, S. D. Robinson, and M. F. Utt1ey;J. C . S. Daltori. 1972, 843. zZbJ.J. Levison and S. D. Robinson, J . Chem. SOC.( A ) , 1970, 2947. 23 B. R. James, R. S. McMillan, and E. Ochiai, Inorg. Nuclear Chem. Letters, 1972,8, 239. 24 R. Mason, K. M. Thomas, D. F. Gill, and B. L. Shaw, J . Organomelallic Chem., 1972, 40, C67. 2 5 J. J. Byerley, G. L. Rempel, N. Takebe, and B. R. James, Chem. Comm., 1971, 1482. " J. G. Bullitt and F. A. Cotton, Inorg. Chim. Actu, 1971, 5, 637. "

352


These paramagnetic species could be oxidized to their diamagnetic Ru"' analogues.27 In a related investigation, the initial grey colour formed in the electrolytic reduction of Ru"'-chloro-complexes has been assigned to unstable monomeric Ru"-chloro compounds. A qualitative visible spectrum was obtained for [RUCI(H,O)~]+(A,, = 530 nm).,* Halogeno-carbonyl and -phosphine complexes. The new dark-brown, iodocarbonyl dimer [NEt,],[Ru,(CO),I,] has been prepared from the reaction of sodium iodide on refluxing ethanolic solutions of RuCl,. Its reactivity paralleled that of Ru(C0)Cl solutions, reacting with triphenyl-phosphine and -arsine to yield cis-[Ru(CO),I,L,], and giving [Ru(CO)I,L,] with triphenylstilbene.,' A re-inve~tigation~~ of the reaction between methyl iodide and [Ru(CO),(PPh,),] has shown that the final product is [MePPh,][Ru(CO),(PPh,)I,], and not [Ru(CO),(PPh,),IMe] as previously r e p ~ r t e d . ~The ' known complex [Ru(CO),(PPh,),I,] was suggested as an intermediate in the reaction. This latter complex was shown to undergo an interesting reversible isomerization : L

oc, I /x ,Ru-X oc I L cis

L

hv

THF, A

oc, I ,x X/?u-co L

trans

which is the first reported example of opposing photochemical and thermal isomerization in such complexes.32Improved syntheses have been reported for a range of noble metal carbonyl complexes, including cis-[RuCl,(CO),(PPh,),]. This method involves the use of ethanolic KOH or NEt, as the basic reducing agent under homogeneous conditions,2 rather than the NaBH, previously employed.22b Convenient syntheses have also appeared for a large number of mononuclear diphenylphosphine complexes, including cis- and trans-[R~Cl,(HPPh,)J.~~ The reaction of MCl-HCl with [RuCl,(CS)(PPh,),], in acetone has produced the red species M[RuCl(CS)(PPh,),] (M = Ph,As+, Ph,BzP+, or Et,N+). These diamagnetic complexes are of interest in view of the scarcity of anionic Ru" compounds.33 The reactivity of [RuCl,(PPh,),] towards various nucleophiles has been investigated. Carbon monoxide gave cis- or tran~-[RuCl,(PPh,),(CO)~], depending on the solvent employed. With nitrous oxide, [RuCl,(PPh,),(NO)] was the final product, whereas sulphur dioxide yielded the complex [RuCl,E. E. Mercer and P. E. Dumas, fnorg. Chem., 1971, 10, 2755. P. E. Dumas and E. E. Mercer, fnorg. Chem., 1972, 11, 531. 2 9 J V Kingston and G R . Scollary. I Innrg Nitclear Chmi., 1972. 34. 221. 30 J. Jeffery and R. J. Mawby, J. Organometallic Chern., 1972, 40,C42. 3 1 J. P. Collman and W. R. Roper, Adi Organowerallic Chem.. 1968, 7, 54 " J. R. Sanders, J. Chem. SOC.( A ) , 1971, 2991. 3 3 T. A. Stephenson and E. Switkes, Inorg. Nuclear Chem. Letters, 1971, 7 , 805. 27

'*

The Noble Metals

353

(PPh,),(SO,)]. The latter complex was qualitatively observed to react with oxygen to give a s u l p h a t o - ~ o m p o u n dNew . ~ ~ complexes of the type CRUX,(CO),L] (X = C1 or Br; L = ROH, py, or RCN) have been obtained by reaction of the dimer [RuX,(CO),], with the appropriate nucleophile. 1.r. data suggest the structure (7) for the new c o r n p l e x e ~ . ~ ~

co

A number of noble metal complexes, including RuCl,(PPh,),, have been reported to catalyse hydrogen-deuterium exchange between D, and 0--Hand N-H-containing molecules such as acetic acid, methanol, ethanol, and m ~ r p h o l i n e .Investigations ~~ of the 31P n.m.r. spectra of a wide range of tertiary phosphine complexes, including the series cis-[RuCl,(CO),L,], has shown a good correlation between the chemical shift of the free phosphine and the change in chemical shift on co-~rdination.~ Hydrido-carbony2 and -phosphine complexes. Several new hydrido-diphenylphosphine complexes have been prepared37 a from the recently described cis- or tran~-[RuCl,(HPPh,),]~~ (Scheme 3). cis-[RuCl,(HPPh,),]

+ LiOMe’z

[RuH(HPPh,),]PF,

(x= C1, Br, I, or SCN)

cis-[RuH,(HPPh,),J

I I

MX

trans-[RuHX(HPPh,),] SnCI,

trans-[RuH(SnCl,)(HPPh,),l Scheine 3

Group VZ Donors. Oxygen donor ligands. A quantitative study has appeared on the uptake of molecular oxygen by [RuCl,(PPh,),]. The data support a pre-equilibrium dissociation producing [RuCl,(PPh,),], which then absorbs oxygen to give the oxygen complex [Ru(0,)Cl,(PPh3),].34 In an interesting communication, Roper et al. have reported the oxidation of alcohol to coordinated carboxylate using a molecular oxygen complex :

S. Cenini, A. Fusi, and G . Capparella, Znorg. Nuclear Chem. Letters, 1972, 8, 127. E. Benedetti, G. Braca, G . Sbrana, F. Salvetti, and B. Grassi, J . Organometallic Chem., 1972, 37, 361. 36 G . G. Eberhardt, M. E. Tadros, and L. Vaska, J . C. S. Chem. Comm., 1972,290. 3 7 B. E. Mann, C. Masters, B. L. Shaw, R. M. Slade, and R. E. Stainbank, Inorg. Nuclear Chem. Letters, 1971, 7, 881. 37a J . R.Sanders, J. C. S. Dalton, 1972, 1333. 34

35

Z

3 54


[Ru(O,)(CO)(CNR)(PP~,),]+ EtOH 5[Ru(O,CMe)(CHNR)(CO)(PPh,),l

An X-ray analysis of the yellow product (see Table 1) confirms the structure (8). PPhi

This unusual reaction also involves H transfer to an isocyanide ligand, a process which was shown38to be reversible by the series of reactions set out in Scheme 4. [Ru(O,CMe)(CHNR)(CO)(PPh,),l

+ NaI -,[RuHI(COXCNR)(PPh,),]

I

XSRt C o ;

[Ru(O,CR')(CHNR)(CO)(PPh,),l

Scheme 4

A related study reports the use of the complexes [Ru(O,)X(NO)(PPh,),] (X = CN, NCS, C1,or OH) as homogeneous catalysts for the oxidation of triphenylphosphine. Only the CN- and NCS- complexes were found to .be oxidized the corresponding AsPh, effective, although [Ru(O,)C~(NO)(PP~,),] in boiling toluene. Kinetic studies suggested38a the oxidation mechanism shown in Scheme 5.

1

PPh,

PPh 3

oll fast

slow

ON,Ru,PPh3 Ph,P' 'NCS

-

PPh,

- ZOPPh, fast

OPPhj ON, I ,Ru-OPPh SCN I PPh 3

3

Scheme 5

The violet complex H[RuCl(H,O)L, J (L = 8-amino-7-hydroxy-4-methylcoumarin) has been isolated from the reaction of free ligand with RuCl, at D. F. Christian, G. R. Clark, W. R. Roper, J. M. Waters, and K. R. Whittle, J . C. S. Chem. Cornrn., 1972,458 3 8 a B. W. Graham, K. R. Laing, C. J. O'Connor, and W. R. Roper, J . C. S. Dalton, 1972, 1237. 38

The Noble Metah

355

low pH. 1.r. studies confirmed co-ordination through both 0 and N.39A subsequent spectroscopic study of a series of metal complexes of this ligand, including the above H[RuCl(H,O)L,], suggests a correlation between certain vibrational bands, e.g. vapvm(NH,). v(M-N), and the stability of the comp o u n d ~In . ~continuing ~ studies of homogeneous hydrogenation catalysts, the violet compound [RuCI,(Hdma)] was obtained after bubbling hydrogen through a solution of RuC1,,3H20 in dimethylacetamide for 4 h at 55°C. The i.r. spectrum indicated ligand co-ordination via an 0 atom. The absence of a Ru-H band suggested that the proton is bonded to the N of dimethylacetarnide., Sulphur donor ligands. The diethyldithiocarbamato-complex [Ru(S,CNEt, )(CHNR)(CO)(PPh,),] has been reported from the reaction of Na,S,CNEt, with [Ru(O,CCH,)(CHNR)(CO)(PPh,),l (see above).38 Simple high-yield preparations of trans-[RuX,(DMSO),] (X = C1 or Br) have been described starting from RuC1,,3H20. Their i.r. spectra show S-co-ordination, and also suggest possible 0-bonding. The complexes are only slowly oxidized in DMSO solution, and are fairly inert to substitution, which contrasts with the air-susceptibility of most Ru" species.41 Examination of the i.r. and especially the 'H n.m.r. spectra of [Ru(NH,),(DMSO)](PF6), suggests that the DMSO is S-bonded to Ru, despite the fact that the v ( S - 0 ) frequency is not shifted significantly from that observed for free DMSO. This conclusion is confirmed from X-ray structural data (see Table l).42 Group V Donors. Molecular nitrogen Complexes. Considerable interest continues in the synthesis and properties of molecular nitrogen complexes. The has been prenew nitrogen-bridged dimer [(H,0),Ru-N,-Ru(H,0),14+ pared by reacting nitrogen gas with [Ru(H20),l2+.It possesses similar physical properties to its amine analogue. Various efforts to reduce the nitrogen to ammonia were u n s u c ~ e s s f u l .A~ ~detailed description of the preparation of [RuH,(N,)L,] [L = PPh, or P(p-MeC6H4),] has appeared,44 following an earlier c o m m ~ n i c a t i o nThe . ~ ~nitrogen in these complexes is readily displaced by hydrogen to give [RuH,(PPh,),]. This in turn reacts with nucleophiles Y to produce [RuH,(PPh,),Y] (Y = NH,, CO, PR3,0r PhCN). An interesting , which observation was the reaction with inner diazonium salts of B, yielded4, complexes containing the Ru-N=N-B moiety, e.g. [RuH,(PPh,)J -k B,oHs(N2)2

-+

[RuH,(PPh,),N,],B,oH,

A new method for preparing molecular nitrogen complexes has been described, involving the attack of NO on a R"'-amine complex: D. K. Rastogi, A. K. Srivastava, P. C. Jain, and B. R. Agarwal, J . Inorg. Nuclear Chem., 1972, 34,1449. 40 D. K. Rastogi, J . Inorg. Nuclear Chem., 1972,34, 619. 4 1 B. R. James, E. Ochiai, and G. L. Rempel, Inorg. Nuclear Chem. Letters, 1971, 7 , 781. 4 2 C. V. Senoff, E. Maslowsky, and R. G. Goel, Cunad. J . Chem., 1971,49, 3585. " C. Creutz and H. Taube, Znorg. Chem., 1971,10,2664. 44 W. H. Knoth, J . Amer. Chem. SOC.,1972,94, 104. 4 5 W. H. Knoth, J . Amer. Chem. SOC.,1968,90, 7172. 39

356

Inorganic Chemistry of the Transition Elements [Ru(NH~)~+ ] ~NO +

+ OH-

-+

[ R U ( N H ~ ) ~ ( N J+ ] ~2H,O +

The method has the advantage of being clean, rapid, and quantitative. Basic conditions are necessary (pH 8.45), and this, together with 15N labelling experiments, suggests a mechanism involving NO attack on a co-ordinated amide group.46 An i.r. and Raman spectral of the deuteriated complexes [Ru(NH,),(N,)]X, (X = C1, Br. 1,or BF,) has resulted in a reassignment of the v(Ru-N) band. This is now shown to be the lowest frequency band (415 cm-') in the Ru-N stretching region, rather than the highest (500 cm- ') as previously proposed.48 A related study of the compounds [Ru(NH,),(X=Y)' '(X=Y = N,, CO, MeCN, CF,CN, PhCN, Bu'CN, or MeNC) has shown that the v(X=Y) stretching frequency increases with increasing counter-ion radius. In contrast, the reverse trend was observed for salts of [(NH,),Ru-N,-Ru(NH3)5]4'. The results were rationalized in terms of interaction between the anions and the ammine ligands, rather than direct interaction with XZEY.,~ Nitrogen 1s binding energies have been determined for a number of complexes, including trans-[ RuCl(N,)(das),]PF, [das = o-phenylenebis(dimethylarsine)], using X-ray photoelectron spectroscopy. Two peaks were observed, the higher energy one being assigned to the N attached to R u . ~ * Nitrosyl complexes. The new cationic nitrosyl complex [Ru(CO),(PPh, ),(NO)]PF, has been prepared oia the action of NOPF, on methanolic solutions of [Ru,(CO),(PPh,),]. The cation may be converted into [RuCI,(PPh,),(NO)] by treatment with CHCl, or chlorine." Convenient syntheses of the species [RuX,(NO)(AR,)~] (X = C1, Br, or I; A = P, R = alkyl, aryl, or alkylaryl; A = As, R = Ph) have been reported using the reagent N-methylN-nitrosotoluene-p-sulphonamide.A mechanism is proposed involving the RuW monohydrides [RuX,H(AR,),] as intermediate^.^^ The first wellcharacterized nitrosyl metalloporphyrin has been isolated :

where (L = mesoporphyrin IX dimethylesterato). A single strong v(N0) band (1735 cm- ') was observed in the i.r. spectrum (CH,Cl,) of the diamagnetic complex.53 New syntheses of the complexes trans-[Ru(NH,),(NO)L]X, (L = C1-, Br-, NCO-, N;, OH-, NH,, or MeCO,: X = C1-, Br-, I-, or C10,) have been described. Using the vibrational frequency v(N0) as an 46

47 48

49

52

''

S. Pel1 and J. N. Armor, J . Amer. Chem. SOC.,1972.94, 686. M . W. Bee, S. F. A, Kettle, and D. B. Powell, 3.C.S. Chem. Comm., 1972, 767. A. D. Allen, F. Bottomley, R. 0. Harris, V. P. Reinsalu, and C. V. Senoff, J . Amer. Chem. SOC., 1967,89, 5595. J. Chatt, G . J. Leigh, and N. Thankarajan, J . C . S . Dalton, 1972, 3168. P. Finn and W. L. Jolly, Inorg. Chem., 1972, 11, 1434. B. F. G. Johnson and J. A. Segal, J . Organometallic Chem., 1971,31, C79. S. D. Robinson and M . F. Uttley, J . C. S. Dalton, 1972, 1. T. S Srivastava. L . Hoffman, and M. Tsutsui, J . Amer. Chem. SOC.,1972,94, 1385.

The Noble Metals

357

-=

indicator, an extended trans-effect series was set up: NH, < NCON; < MeCO, < C1- < Br-. A detailed examination of the magnetic c.d., i.r.. and u.v.-visible spectra confirms that these complexes contain the RuII-NO group, rather than the intermolecular antiferromagnetic moiety RU"'---NO.~~ The recently reported55 reaction of azide ion with [Ru(bipy),(NO)X]'+ in water to give [Ru(bipy),(H,O)X]+ (X = C1) plus nitrogen, has been extended to non-aqueous solvents and X = C1, I, or NO,. Complexes of the type [Ru(bipy),X(S)]+ (S = H 2 0 , Me,CO, or MeOH) were obtained, the acetone complex being a convenient precursor for the preparation of cis-[ Ru(bipy),XY]+.* (Y = NO,, C1, or p ~ ) A. detailed ~ ~ spectroscopic and preparative study of hydroxide attack on co-ordinated NO in [Ru(AA),X(NO)]'+ (A = bipy or phen; X = C1, Br, NO,, or py) has appeared57 following an earlier c o m m ~ n i c a t i o nThe . ~ ~ equilibrium constant K for the process is a factor of +

lo3 higher than for the analogous equilibrium with [Fe(CN),N0I2-. This higher affinity of ruthenium-co-ordinated N O for OH- is in keeping with its postulation as NO+.57 Studies of the photolysis of solutions of K2[RuC15(NO)] in 8M-HC1 indicate the formation of RuI'I- or Ru'v-chloro complexes, depending on the reaction atmosphere employed.59 The data suggest the mechanism shown in Scheme 6. Ru(NO)ClxA *Ru(NO)Clx *Ru(NO)Clx-Ru"'Clx

-

NO,

NO + to, NO2 + Ru"'Clx -Rul"Clx

+ NO + NO

Scheme 6

Nitrogen 1s binding energies have been determined by X-ray photoelectron spectroscopy for a large number of nitrosyl complexes, including trans[RuCl(NO)(das),]Cl,, [RuCI(NO)~(PP~,),] PF,, and [Ru,(CO), o(NO)2]. Among the several interesting conclusions arising from this study were: (i) bent NO groups have low binding energies: (ii) although linear NO groups can have a range of energies, there is a rough correlation between v(N0) and binding energies; and (iii) terminal and bridging NO groups apparently have 54

A. F. Schreiner, S. W. Lin, P. J. Hauser, E. A. Hopcus, D. J. Hamm, and J. D. Gunter, Inorg. Chem., 1972, 11, 880.

F. J. Miller and T. J. Meyer, J . Amer. Chem. SOC., 1971, 93, 1294. 5 6 S. A. Adeyemi, F. J. Miller, and T. J. Meyer, Znorg. Chem., 1972, 11, 994. 5 7 J. B. Godwin and T. J. Meyer, Inorg. Chem., 1971, 10, 2150. J. B. Godwin and T. J. Meyer, Inorg. Chem., 1971,10,471. '' A. B. Cox and R. M. Wallace, Inorg. Nuclear Chem. Letters, 1971,7, 1191.

55


358

very similar electron densities since they are indistinguishable by this method.60 Other nitrogen donor ligands. The blue complex frequently reported in the literature as resulting from the action of HC1 on [Ru(NH,),]CI,, has been isolated as deep-blue crystals of [Ru ,(NH,),C14(H20)]C1. An analogous complex was obtained with HBr. These compounds were shown to be mixed Ru"-Ru"' dimers from their magnetic moments (p z 2.0 BM), and the fact that 50% of the complex could be easily oxidized. 1.r. data suggest a single halogen bridge." A series of complexes of the unusual 1,3-diaryltriazenido ligand (9)

has been prepared, including [RuCl(CO)(PPh,),L'], [RuH(CO)(PPh3),L2], and [Ru(PPh,),Lf] (L' = 1,3-di-p-tolyltriazenido;L2 = 1,3-diphenyltriazenido). The i.r. spectra of these diamagnetic, highly coloured solids indicate bidentate co-ordination of L.,' The new complexes cis-[RuX,(py),] (X = +ox, CI, Br, or I) have been prepared (Scheme 7). Their cis configuration was assigned by comparison of K,[Ru(Ox),], xH,O

+ py Hio *green soln

I I

Zn-Hg

Scheme 7

their far ix., Raman. and 'H n.m.r. spectra with those of the known tvansisomers.63 The reaction of [ArN,]BF, (Ar = p-MeC6H4 or p-MeOC,H,) with [RuHCl(PPh,),] in cold acetone has produced the yellow complex [RuCl(PPh,),(N,Ar),]. This air-stable compound is the first known complex containing two arylazo-ligands bonded to the same metal. Its reaction with chlorine, yielding [Ru(PPh,),(N,Ar)Cl,], supports the belief that the arylazoligands are separate and not coupling as a tetrazene ligand.64 Several papers have appeared concerning Ru"-porphyrin complexes. The first examples of metalloporphyrin dimers linked by M-M bonds have been synthesized : [Ru(CO)L(py)] 2[(py)LRu=RuL(py)]

+ CO

[L(py) = etioporphyrin-1-pyridinateor octaethylporphyrin pyridinate]. The 6o

P. F i n n and W . L . Jolly, Inorg. Chem., 1972, 11, 893.

61

F. Bottomley and S. B. Tong, Canad. J . Chem.. 1971,49, 3739. S. D. Robinson and M. F. Uttley, Chem. Cornrn., 1971, 1315. D. W . Raichart and H . Taube, Inorg. Chern., 1972, 11, 999. J. A. McCleverty and R. N. Whiteley, Chem. Comm., 1971, 1159.

62 63 64

The Noble Metals

359

reaction is quantitative, and may be potentially useful for making other metalloporphyrin d i m e r ~ Another .~~ report describes the preparation of [L(CO)Ru]4,4'-bipy-[ Ru(CO)L] [L = tetra(p4sopropylphenyl)porphine (lo)] which is the first known bridged dinuclear Ru-porphine complex. R

R (10) R = p-isopropylphenyl

The monomers [Ru(CO)LX] (X = 4-Bu'py or 3,5-dimethylpyrazole) were also synthesized. An examination of the temperature-dependent 'H n.m.r. spectrum of [Ru(CO)L(4-Butpy)] in the presence of excess 4-Bu'py indicates that exchange of X is intermolecular.66 A subsequent and more detailed 'H n.m.r. study of the exchange between [Ru(CO)L] and various nitrogen bases showed that intermolecular exchange is general. However, for the bases 3,6dimethylpyridazine and 4,5-dimethylpyridazine, intramolecular X exchange is also indicated (20-85 times faster than i n t e r m ~ l e c u l a r ) . ~ ~ Taube's recent isolation6* of a pyrazine-bridged RU"-RU"' dimer

has generated considerable preparative and theoretical interest. A general synthetic route to a range of ligand-bridged Ru"-bipyridyl complexes has been found using the sequence [Ru(bipy),(NO)Cl]'+

+ N; + S + [Ru(bipy),(S)CI]+ + N, + H,O

[Ru(bipy),CI(N

-

IN-.

N)]

+ [(bipy),ClRu-(N

[S = H,O, MeCN, MeOH, or Me,CO; N

-

-

NFRuCl(bipy),]'

N = pyrazine, 4,4'-bipyridine, or trans-1,2-bis-(4-pyridyl)ethylene]. Starting with [ R ~ ( b i p y ) ~ ( N O ) ( N 0 , ) ] ~ + , and employing the reaction of Ru-NO, complexes with acid to yield Ru-NO

65 66 67

60

G. W. Sovocool, F. R. Hopf, and D. G. Whitten, J . Amer. Chem. Soc., 1972,94,4350. S. S. Eaton, G. R. Eaton, and R. H. Holm, J . Organometallic Chem., 1971, 32, C52. S. S. Eaton, G. R. Eaton, and R. H. Holm, J . Organometallic Chem., 1972, 39, 179. C. Creutz and H.Taube, J . Amer. Chem. Soc., 1969,91, 3988.

360


in combination with the above reactions, has yielded more highly linked compounds, such as [(bipy),C1Ru(pyz)Ru(bipy),(pyz)Ru(bipy),(pyz)RuCl(bipy),16 +. Electrochemical studies of their redox properties were carried dimer was produced by the Ag+ Although Taube's pyrazine Ru"-Ru"' oxidation of [(NH,),Ru-NC,H,N-RU(NH,),]~+, attempts to prepare similar Ru"-Ru"' complexes from [( NH ,), Ru(C,H,N), Ru( NH3)5]4' and [(NH,),RU-NC,H,C,H,C~H~N-RU(NH~),]~+ were unsuccessful. Cyclic voltammetric data indicated a two-electron oxidation to Ru"'-Ru'" d i m e r ~ . ~ ' In view of the identical ligands around each Ru atom, Mayoh and Day have questioned the localization of the Ru valencies in Taube's dimer into discrete Ru" and Ru"' centres. However, a theoretical calculation of the conditions necessary for valence trapping in any mixed valence system, showed that the ~' workers have condition is indeed satisfied by the above Ru c ~ m p o u n d . Other suggested that the available data on this complex could also be explained by a molecular orbital scheme in which the Ru ion and pyrazine-filled IT (or n") molecular orbitals are mixed, and the unpaired electron is mainly but unsymmetrically shared by the two cation^.'^ Complexes of the type [Ru(NH3),LI2+ and [Ru(NH3),],L4+ [L = pyridine: 4-phenylpyridine: 4,4'-bipyridine: 1,2-bis-(4-pyridyl)ethylene] have been prepared by reaction of the stoicheiometric amount of ligand with [Ru(NH,),(H,O)]". U.v.-visible and 'H n.m.r. studies suggested that the ligand obtains ~ ~ charge-transfer spectra of a net positive charge on c ~ m p l e x a t i o n .The R u n complexes of the type [Ru(NH,),L]'+ and cis- and trans-[Ru(NH,),L,I2 + (L = pyridine, isonicotinamide, methylisonicotinamide, or pyrazine) have been measured. A simple molecular orbital treatment involving only one Ru 5d orbital and one ligand n* orbital gives semiquantitative agreement with the experimental data.', An e.s.r. examination of diamagnetic K,[Ru(CN),],3H20 irradiated with X-rays at room temperature suggests the formation of the species [Ru(CN),(NC)]'-. Similarly, [Ru(CN),(NC),]~- is observed after y-ray irradiation at 77 K, together with the HCN- radical.75 Nitrogen 1s binding energies have been determined for a number of comThe plexes. including rrans-[Ru(N,)Cl(da~)~]PF,and K,[Ru,NCl,(H,O),]. azide complex has a very similar X-ray p.e. spectrum to that of NaN,, indicating that the internal bonding of azide is essentially unaffected by co-ordination i.e. the azide appears to be bound to the Ru by an essentially ionic bond.,' An interesting demonstration of the power of X-ray p.e. spectroscopy as a diagnostic tool is the identification of the product of oxidation of [Ru(en),12+ 69

'I0 71 'I2

'I3 74 'I5

S. A. Adeyerni, J. N. Braddock, G. M. Brown, J. A. Ferguson, F. J. Miller, and T. J. Meyer, J. Amer. Chem SOC.,1972,94, 300. E. D. Fleischer and D . K. Lavallee, J. Amer. Chem. SOC.,1972, 94, 2599. B. Mayoh and P. Day, J. Amer. Chem. Soc., 1972, 94, 2885. J . H. Elias and R. S. Dragon, Inorg. Chem., 1972, 11, 415. D. J. Lavalle and E. B. Fleischer, J. Amer. Chem. SOC.,1972, 94, 2583. A. M . Zivichel and C . Creutz, Inorg. Chern., 1971, 10, 2395. R. S. Eachus and F. G. Herring, Canad. J . Chem., 1972, SO, 162.

The Noble Metals

36 1

or [Ru(en),13+ as the a-di-imine chelate complex (ll).76The magnitude of the Ru 3d3 electron-binding energies clearly eliminates its previous characterization as the Ru"' complex [Ru(en), - 4H]I,.77 (The binding energy is r

H

2+

H '

between those for typical Ru" and Ru"' complexes, and its diamagnetism establishes it as Ru".) The i.r. and 'H n.m.r. spectra are consistent with this kinetic study of the reduction of [Ru(NH,),(N,O)]~+ with f ~ r r n u l a t i o n .A~ ~ Cr2+ or V 2 + , shows that co-ordination of N 2 0 to Ru causes an increase in An outer-sphere mechanism is proposed with reduction rate of lo7-lo'. cr2+ 78

Several reports have appeared concerning the luminescence of Ru"-bipyridyl and -phenanthroline type complexes. The variation of luminescence intensity with temperature has been studied over the range - 196-50 "C for the complexes cis-[RuX,(phen),] (X = C1, CN, +ox, H,O, or py). Considerable variation in intensity is observed with temperature and crystal field strength of X. The results emphasize the important contribution of excited-state spin crossover to the luminescent properties of metal complexes.79 Luminescence quantum yields have been measured for several complexes, including [RuL,]C12 (L = 4,4'-diphenyl-2,2'-bipyridyl or 4,7-diphenyl- 1,lo-phenanthroline). From a comparison with the parent bipyridyl and phenanthroline complexes, a quantitative estimate was obtained of the effects of ligand phenyl substituents on the quantum yields etc." During a cyclic voltammetric study of [Ru(bipy),]C1, in acetonitrile, luminescence was observed when the potential was cycled between the voltage of the 3 + and 2 + species. This is the first reported example of electrogenerated chemiluminescence for such compounds.' Phosphorus, arsenic, and antimony donor ligands. A general synthesis has been reported for trialkyl phosphite complexes of noble metals, including [RUL,]'+, [RuXL,]+, and [RuHL,]' [L = P(OMe), or P(OEt),; X = C1 or Br]. The complexes were isolated as their tetraphenylborate salts from reaction of the phosphite with methanolic solutions of suitable labile olefin 76

77

78

79

''

B. C. Lane, J. E. Lester, and F. Basolo, Chem. Comm., 1971, 1618. H. Elsbernd and J. K. Beattie, J . Chem. SOC.( A ) , 1970,2598. J. N. Armor and H. Taube, J . Amer. Chem. SOC.,1971,93,6476. G. M. White and W. E. Ohnesorge, J . Inorg. Nuclear Chem., 1972,34, 1453. R. J. Watts and G. A. Crosby, J . Amer. Chem. SOC.,1972,94,2606. N. E. Toke1 and A. J. Bard, J . Amer. Chem. SOC.,1972,94,2862.


362

or phosphine complexes.82The complex trans-[RuCl,(AsPh,),(CO),] has been reported from the action of CO on [RuCl,(AsPh,),(MeOH)]. Its i.r. spectrum suggests the configuration (12).83 CI

OC,

I ,AsPh,

Ph ?As/T(U \CO -

c1

Group IF' Donors. Carbon donor ligands. The preparation of the isocyanide complexes trans-[Ru(CNEt),(APh,),X,] (A = P, As, or Sb; X = C1 or Br) (13) has been described in following an earlier c o r n m ~ n i c a t i o n . ~ ~ Isomerization to the cis-complexes (14) is achieved by heating in the solid state or in 2-methoxyethanol, the configurations being confirmed from i.r. and Raman studies. CNEt

L,l

L

,x

X/TU\L CNEt

Cationic y-0x0-isocyanato Run complexes have been isolated : [Ru(CN),I4-

+ 12MeCOMe + 6R,O+BF; [Ru(C=N-CMe2-CH,COMe),](BF,),

+ 6R,O + ROH

for (R = Et or n-C,H,). Their 'H n.m.r. spectra confirm the presence of a keto-group in position 3 relative to the isocyanide group. The complexes are apparently formed via acid-catalysed aldol condensation of acetone, in which the carbonium ion of dimer acetone is trapped by nucleophilic attack of a co-ordinated cyano-ligand.86 A re-investigation of [RuCl,(CN Et),] using i.r. and Raman techniques has shown that the yellow form has a trans configuration. Reaction of this complex with SnCl, and HgC1, yielded the species tr~ns-[Ru(SnCl,),(CNEt)~]and RuCl,(CNEt),,HgCl,, r e ~ p e c t i v e l y . ~ ~ Silicon, germanium, and tin donor ligands. An interesting report has revealed that carbon monoxide exchange in cis-[Ru(CO),(SiCl,),] (1 5) is stereospecific, 82

83 84 85

86

D. A. Couch and S. D. Robinson, Chem. Comm., 1971, 1508. E. S. Switkes, L. Ruiz-Ramirez. T. A. Stephenson, and J. Sinclair, Inorg. Nuclear Chem. Letters, 1972, 8, 593. B. E. Prater, J . Organometallic Chem.. 1972, 34, 379. B. E. Prater, J . Organometallic Chem., 1971, 27, C17. M . Schaal and W. Beck, Angew. Chem. Internat. Edn., 1972, 11, 527. B. E. Prater, J . Organometallic Chem., 1971,33, 215.

The Noble Metals

363

i.e. only the equatorial CO groups exchange. A similar result was observed with cis-[Ru(CO),(CeCl,),] although exchange was very slow. These compounds provide one of a very few examples of site preference in CO exchange

co CO

reactions. The observations are rationalized in terms of a common stable five-co-ordinated intermediate (16)in which both SiCl, groups are equatorial." A related kinetic study of the isomerization of cis-[Ru(CO),(SiCl,),] to the

co I

,SiC13

OC-Ru

I 'Sic1 CO

trans-isomer in n-octane suggests that the process is non-dissociative (ASs = -6.9 em). These species may therefore provide a rare example of stereochemical non-rigidity in non-chelate octahedral c o r n p l e x e ~ . ~ ~ Group 111 Donors. Boron donor Iigands. The unusual tris(pyrazoly1)boratocomplex [RuL,(CO),X] [X = C1, Br, or I; L = (16a)l has been prepared: [Ru,(CO),,]

+ KL-

red soh

A [RuL,(CO),X]

H

( 164

The inertness of these white-yellow complexes was ascribed to strengthening of the Ru-X bond due to reduced n-acceptor power of L compared with the cyclopent adien yl group. O Rutheniurn(rrr).-Group VII Donors. The consecutive stability constants K , - K , of chloro-complexes of Ru"' have been determined in aqueous and aqueous-alcoholic 1 N-HC10,.91 Other Russian workers have compared the

89 90 91

R. K. Pomeroy, R. S. Gay, G. 0. Evans, and W. A. G. Graham, J . Amer. Chem. SOC.,1972, 94,272. R. K. Pomeroy and W. A. G. Graham, J . Amer. Chem. Soc., 1972,94,274. M. I. Bruce, D. N. Sharrocks, and F. G. A. Stone, J . Organometallic Chem., 1971, 31,269. A. T. Pilipenko, I. P. Sereda, and Z. A. Semchinskaya, R u n . J . Znorg. Chem., 1971, 16, 1349.

364


catalytic properties of K,[RuCl,(H,O)] and K,[Ru20C1,,] in the oxidation of amines such as benzidine and I, by periodate ion or hydrogen p e r ~ x i d e . ~ ' Group V I Donors. Oxjyen donor ligands. A series of unsymmetrical tris-(pdiketonato)M'**complexes (1 7) has been investigated in order to establish cis-trans isomer distributions, and relative rates of isomerization. Included in this study was the preparation and separation of the geometric isomers of [Ru(tfac)J and [Ru(bzac),] (tfac = trifluoroacetylacetone, bzac = benzoylacetylacetone). In weakly polar media, the trans-isomer of [Ru(tfac),] was found to be more stable, whereas the isomer distribution of similar complexes with Rz,RY= alkyl or Ph. is ~ t a t i s t i c a l . ~ ~

(L = 8-amino-7-hydroxy-4-methylThe black complex [RuL,(H,O),]CI coumarin) has been isolated from the reaction of free ligand with RuC1, at pH 8. 1.r. studies confirmed ligand co-ordination through 0 and N.39 A subsequent spectroscopic study of a series of metal complexes of this ligand, including the above [RuL2(H20),]Cl, suggests a correlation between certain v(M-N)] and the stability of the comvibrational bands [e.g. vaSym(NH2), plexe~.~'A green dinuclear complex of tris(hydroxymethy1)aminoethane has been briefly described, with the formula [IR UNH, C(CH ,O)(CH 20H),Cl] Cl,. On the basis of its diamagnetism and other spectral data, a structure (18) was proposed involving a Ru-Ru bond and alkoxide linkages.94

c1 0

0

Sulphur donor ligands. Dialkyl- and diphenyl-thioethane complexes have been synthesized via the route shown in Scheme 8; 1.r. and magnetic studies 92

93 94

V. E. Kalinina, R. P. Morozova, K. B. Yatsimirskii, and 0. N. Ignat'eva, Russ. J . Inorg. Chern., 1971,16,582. J. G. Gordon, M. J. O'Connor, and R. H. Holm, Inorg. Chim. Acta, 1971,5 , 381. R. L. Dotson, Inorg. Nuclear Chem. Letters, 1972,8, 353.

The Noble Metals RuC1,

365

+ RSCH,CH,SR

(R

=

levap

F R u C 1 , L (R = Me or Ph)

evap

Ph) RuC1,,2L -RuCI,,~~L

(R

=

Me or Et)

Scheme 8

suggest the structures (19)-(21), respectively. Similar complexes of 1,4-thioxan (RuC13,3L) and 1,4-dithian (RuCl,,liL) were also reported.95 Stability constants have been determined for the stepwise formation of the complexes S

c1

c1

S\&S

): :u: : :*:(

c1

c1 (19)

c1\ I

/s

\

(s/y\chs/$ (20)

I s

I/Cl

ku k/ /I

c1

c1

c1

S

\

/s c1

/I

\

c1

S\

(21)

[RuCl,L(H,O)] -, [RuCI,L,(H,O)], and [RuCl,L,H,O] + [L = SC(NH,),, and various substituted thioureas] from HCI solutions of [RuCI,(H,O)]~ -. The data show that substituted thioureas form less stable c ~ m p l e x e s .A~ ~ series of unsymmetrical tris-( P-thioketonato)M" complexes (including M = Ru"') have been investigated in order to establish cis-trans isomer distributions and relative rates of i s ~ m e r i z a t i o n . ~ ~

Group V Donors. Nitrogen donor ligands. Strong u.v.-visible spectral evidence has been found97 for the amido-complex [RU(NH,)~(NH,)]~',formed on addition of O H - to [Ru(NH3),I3+. A strong peak appearing at 402 nm is ascribed to the amido-species, which then undergoes slow hydrolysis to yield [Ru(NH,),OH]'+. This report is interesting on two counts: (i) apart from PtIV, no other deprotonated metal hexammine has been established: and (ii) it lends strong support to the S,lcb mechanism proposed9' for base hydrolysis of Ru"' ammine complexes. The pK, for formation of [Ru(NH,),(NHJ],' was calculated as 12.4 from studies of the variation of A,2o with [OH-].97 Following the recent success of Mossbauer spectroscopy in elucidating mixed oxidation states in metal complexes, it has now been applied to the 'ruthenium reds'. The Mossbauer spectrum of ruthenium red at 4.2 K confirms the presence of both Ru'" and Ru", in the ratio 2: l.99This is consistent with Fletcher's trinuclear formation [(NH,)5RuORu(NH,),0Ru(NH,),]6f.'00 Similarly, the spectrum of ruthenium brown shows the presence of Ru"' and RuW in the ratio 1:2. This confirmation of discrete Ru oxidation 95

96

91

98

99 loo

D. A. Rice and C. W. Timewell, Znorg. Chim. Acta, 1971, 5, 683. A. T. Pilipenko, I. P. Sereda, Z. A. Semchinskaya, andV. I. Golub, Russ. J . Znorg. Chem., 1971, 16, 1635. D. Waysbort and G. Navon, Chem. Comm., 1971, 1410. F. Basolo and R. G. Pearson, in 'Mechanisms of Inorganic Reactions', Wiley, New York, 1967, 2nd edn., p. 183. C. A. Clausen, R. A. Prados, and M. L. Good, Inorg. Nuclear Chem. Letters, 1971, 7, 485. J. M. Fletcher, B. F. Greenfield, C. J. Hardy, D. Scargill, and J. L. Woodward, J . Chem. Soc., 1961, 2000.

366


states indicates that the deep colours of these species cannot be assigned to oscillating ~ a l e n c i e s . ~ ~ Phosphorus and arsenic ligands. The complexes [RuX,(APh,),(S)] (X = C1 or Br: A = P or As; S = MeOH or MeNO,) have proved useful starting materials for the synthesis of several new phosphine and arsine complexes. Reaction with nitriles. acetone. THF. DMSO. and CS,. yielded complexes of the type [RuX,(APh,),L]. 1.r. studies indicate N-co-ordination for L = RCN R = Me, Ph, PhCh,, or CH,=CH), whereas DMSO is 0-bonded. On the other hand, reaction with nucleophiles such as Me,S, py, bipy, and phen, gave the compounds [RuX,(APh,)L,]. The tris-complex [Ru(S,PPh,),] was obtained from reaction with excess NaS,PPh, . 8 3 Group IV Dorrors. The preparation of the complexes cis-[Ru(CNEt),(APh,),(SnCI,)Cl] (A = P, As, or Sb) for the treatment of c*i.s-[Ru(CNEt),(APh,),Cl,] with SnCl,. provides another example of insertion of SnCI, into a M-C1 bond. The structure (22) was proposed from i.r. data.'"

EtNC,

I

,SnCI,

EtNC+Cl

Ruthenium( rv).-Several novel R u ' ~compounds have been isolated from the reaction sequence shown in Scheme 9. These diamagnetic complexes are assumed to be mononuclear with two trans oxide groups. In addition, the dinuclear complex [Ru(OH),(phen)],O was reported to be formed by evaporating a methanolic solution of [RuO,(phen)],O.'"' A study of the mechanism

of extraction of [RuC1,I2- from HCl solutions by aliphatic amines indicated ' ~ ~ consecutive stability the formation of (AmH)2[RuCl,] type c o m p l e x e ~ . The

lo'

lo2

lo3

B. E. Prater, Inorg. Nuclear Chem. Letters, 1971, 7, 1071. T. Ishiyama, Bull. Chem. SOC.Japan, 1971,44, 1571. K. A. Boi'shakov, N. M. Sinitsyn, V. V. Borisov. and S. M. Vaseneva, Russ. J . Inorg. Chem., 1971, 16, 1047.

367

The Noble Metals Table 1 X-Ray data for ruthenium compounds Compound RuH(NO)(PPh,),

R 0.062

0.065

0.022

0.095 0.059 0.057 0.021 0.047 0.054 0.072

0.038

0.028

[RuC1(CO),(PBu', p-Tol)],

0.047

Ru(O,CMe)(CHNR)(CO)(PPh,) 0.08

Comments Distorted trigonal bipyramid with NO and H axial. Ru-N-0 is linear. Distorted square-pyramid. An axial NO co-ordinates in a bent manner, while the equatorial Ru-N-0 is linear. Anion is a distorted octahedron with a linear Ru-N-0. A previous X-ray study shown to be in error. Tetrahedron of one Fe and three Ru atoms Tetrahedron of Ru atoms. Contains eleven terminal and two bridging CO groups. Octahedron of Ru atoms. Suggest triply bridging H ligands in trans sites. Regular octahedron. Regular octahedron. Ru"'-N distance is 0.040 A shorter than for Ru"-N. DMSO co-ordinates through S. Triangle of Ru atoms form part of first established six-membered heterocyclic metal ring system. Distorted octahedron. Pyridine-2thiolato(pyS) is bidentate, such that S atoms are trans. Three Ru atoms at vertices of an isosceles triangle. Two NO groups bridge two of Ru atoms. Ru-Ru distance is much shorter than other Ru' or Ruo polymers. This fact, together with nonplanarity of C1 bridge system, suggests a bent Ru-Ru bond (formed by overlap of essentially octahedral hybrid orbitals). Confirms structure (8) with bidentate carboxylate group.

Ref: a

b

C

d

e

f 9 9

h 1

j

k 1

m

(a)C. G. Pierpont and R. Eisenberg, Inorg. Chem., 1972,11,1094;(b)C. G..Pierpont and R. Eisenberg, Inorg. Chem., 1972,11,1088;(c) J. T. Veal and D. J. Hodgson, Inorg. Chem., 1972,11,1420:(d)ref. 19; (e) ref. 18; (f)ref. 20; (9) H. C. Stynes and J. A. Ibers, Inorg. Chern., 1971, 10, 2304: (h) F. C. March and G. Ferguson, Canad. J. Chem., 1971,49,3590; (i) J. Howard and P. Woodward, J. Chem. SOC.( A ) , 1971,3648; 6)S. R. Fletcher and A. C. Skapski, J.C.S Dalton, 1972,635;( k ) J. R. Norton, J. P. Collman, G. Dolcetti, and W. T. Robinson, Inorg. Chem., 1972,11,382; (0 ref. 24: ( m ) ref. 38.


368

constants Ki-K, of chlorocomplexes of RuW have been determined in aqueous and aqueous-alcoholic lN-HC10,.9 Ruthenium(v) and Higher Oxidation States.-Polarographic investigations have shown that RuV (e.g. R u 2 0 5 ) has a catalytic influence on the electrochemical reduction of Ru. It dissolves in dilute H,SO, solutions containing RuW to produce polymeric Ru species with formal oxidation state 4.2.lo4 The red-brown periodate-Ruv' complex Na6[Ru(I0,)(OH),],1 8 H 2 0 has been described. Its diamagnetism suggests polymerization involving 0x0-bridging between Ru atoms.'05 Reduction of [RuO,(bipy)] with methanol has been reported to give the new [RuO,(OH),(bipy)], which is assumed to be a 'ruthenyl' complex with the two oxide ligands trans.102Raman and i.r. spectra have been recorded for a large number of metal tetra-0x0-complexes, including K,[RuO,] and K[RuO,]. From detailed band assignment^'^^ it was shown that force constants decrease with decreasing oxidation state for a given metal i.e. RuV"' > Ru"" > Ru'". 2 Osmium Cluster Compounds.-The green nitrosyl cluster Os,(CO) ,(NO), has been reported in 137; yield from the reaction of NO with Os,(CO),, in benzene. Its i.r. spectrum suggests bridging nitrosyl groups, which was confirmed from an X-ray analysis of the Ru analogue. 1.r. studies show that the structure (23)

is maintained in solution.8 Pyrolysis of solid Os,(CO),, has been shown to yield the following six products which were separated by t.1.c.: Os,(CO),,, Os,(CO),,, Os,(CO), 8 , OS,(CO)~,,Os,(CO),,, and Os,(CO),,C,. All were identified by mass spectroscopy, and their i.r. spectra revealed the absence of bridging carbonyl groups. It is interesting that. unlike the pyrolysis of ) ~ , was formed.' The thermal reaction between Ru,(CO),,, no O S ~ C ( C Ocarbide Os,(CO),, and Mn,(CO),, or Re,(CO),, has yielded mixed cluster compounds of the type [(CO),MOs(CO),M(CO),] (M = Mn or Re)." Analogy with the known [(CO),MnFe(CO),Mn(CO),] l 2 suggests the structure (4;M = 0s). Similar mixed clusters have been reported from the treatment of Os,(CO),, '04 lo'

D. K. Avdeev, V. I. Seregin, and E. N. Tekster, Russ. J. Inorg. Chem., 1971, 16, 592. E. E. Mercer and S. M. Meyer, J . Inorg. Nuclear Chem., 1972,34, 777. F. Gonzalez-Vilchez and W. P. Grifiths, J . C . S . Dalton, 1972, 1416.

The Noble Metals

369

with the anions [M(CO),]- (M = Mn or Re) in various solvents. However, the reaction gives a complex mixture of anionic species from which only (Me,N)[MOs,(CO),,] could be separated in pure form. Its i.r. spectrum indicated only terminal CO groups, suggesting the structure (23a). Acidification

/\ of the reaction mixtures yielded more readily isolable neutral hydridocomplexes, including the new [HMOs,(CO), ,], [HMOS,(CO),~],[H,MOs,(CO)13], and [HReOs,(CO), 5].1 2Q Two related papers have appeared describing the reactions of OS,(CO),, with Group IV donor ligands. The thermal reaction with trimethylgermane in hexane yielded a mixture of [Os(Me,Ge),(CO),] and [(Me,Ge)Os(CO),(p-GeMe,)],. In contrast, the major photochemical product was [Os(Me,Ge)(CO),H]. Pyrolysis of [0~(Me,Ge),(C0)~]produced the interesting clusters [Os,(CO),(Me,Ge),] ( 5 ; M = 0 s ) and [OS2(Me2Ge),(CO)6], both of which involve Me,Ge bridging group^.'^ Similarly, the thermal or photochemical reaction of Os,(CO),, with Me,SiH gave [ ( M ~ , S ~ ) O S ( C O ) ~ ( ~ - S ~ M ~ , ) ] , . The resemblance of its i.r. and 'H n.m.r. spectra to those of the known Sn analogue suggests the structure (24). In addition, the silicon analogue of (5)

was obtained from the reaction of OsH,(CO), with Me,Si,H." A detailed study of the action of triphenylphosphine of Os,(CO),, has revealed the production of not only the known [OS,(CO),,-~(PP~,),](n = 1, 2, or 3) but also three hydrides (from i.r. and 'H n.m.r.), and the novel complexes [HOs,[os3(Co)8(PPh2)(Ph)(pphc6H4~]~ and [os3(CO),(PPh,)(PPh,C,H,)], (CO),(PPh,),(C6H4)], for which three X-ray studies were reported.'07 Lr. and Raman spectral studies of the cage compound oS4o,(co)12have indicated a tetrahedral symmetry in solution. A partial normal-co-ordinate analysis gave approximate CO stretching force constants. lo' An interesting lo' lo*

2A

C. W. Bradford, R. S. Nyholm, G. J. Gainsford, J. M. Guss, P. R. Ireland, and R. Mason, J . C . S. Chem. Comm., 1972,87. W. Van Bronswyk and R . J. H. Clark, Spectrochim Acta, 1972,28A, 1429.


370

development has been the application of inelastic neutron scattering spectroscopy (INS) to metal clusters. This non-destructive method has led to the assignment of structures and force fields to a number of clusters, including HOS,(CO),,.‘~~

Osmium-(0) and -(I).-The complex [Os(CO),(PPh,),] has been prepared (Scheme I?); its single v(C0) band indicates equatorial phosphines and trans [OsHCl(CO)(PPh,),]

+ AgClO,=

[OsH(CO)(CH,CN)2(PPh3)2]C104

\

fast CO

+ AgCl -t PPh,

soln

Scheme 10

CO groups. An interesting property of the new complex is its ability to pick up oxygen in solution to produce the first reported 0s-molecular oxygen species, [Os(0,)(CO),(PPh,),].22 A theoretical treatment of the CO stretching vibrations of some dinuclear metal carbonyls, including [Os,(O,CMe),(CO),], indicates that the intermolecular coupling and other interactions between CO groups are principally due to dipole4ipole forces.26

Osmium(i1). -Group VII Donor Ligands. Halogeno-phosphine complexes. Convenient syntheses have been described for a range of mononuclear diphenylphosphine complexes, including cis- and trans-[OsCl,(HPPh,),]. Like the known bis(ditertiary phosphine) complexes, these compounds do not dissociate in solution and the phosphine ligands are not readily displaced by other groups.30 A number of noble metal complexes, including [OsBr,(PPh,),], have been reported to catalyse hydrogen-deuterium exchange between D, and molecules such as acetic acid, methanol, ethanol, and morph01ine.~ Hydrido-carbonyl phosphine complexes. The use of ethanolic KOH or NEt, as a basic reducing agent instead of NaBH, has provided improved syntheses for a range of noble metal hydrido-carbonyl complexes, including [OsH,(CO)(PPh,),], [OsH,(CO),(PPh,),]. and [OsHC1(CO)(PPh,),].22” Group I/ Ligands. Molecular nitrogen complexes. No new molecular nitrogen complexes have been reported, but several spectroscopic studies have appeared. In one of the first photochemical studies of transition metal-nitrogen complexes, the compound [Os(N,)Cl,(PEt,Ph),] was irradiated (Hg lamp) in THF solution while bubbling through CO gas. The products were mer[OsClz(CO)(PEt,Ph),], and cis- and trans-[OsC12(C0)2(PEt,Ph)2].110 A Raman study of aqueous solutions of [Os(N, )(NH,),]Cl, has confirmed the previous assignment at 518 cm- to the v(0s-N,) vibration.47Measurements ‘09

J. W. White and C. J . Wright, J . Chem. SOC.( A ) ,

‘lo

D. J. Darensbourg, Inorg. Nuclear Chem. Letters, 1972, 8, 529.

1971, 2843.

The Noble Metals

37 1

of integrated i.r. intensities for metal-nitrogen complexes continue to provide valuable information with a study of the series [Os(N,)(PR,Ph),X,] (X = C1 or Br; R = Me or Et), and their CO analogues. Since the group dipole moment derivatives were substantially higher for the CO complexes, it was concluded that nitrogen is a weaker o-donor and n-acceptor than CO. It is comforting that, in contrast with data using only relative i.r. frequency shifts of v(N,) or v(CO), the intensity data correlate well with conclusions from Mossbauer, A stability, and reactivity studies, and molecular orbital calculations.' related study of molecular nitrogen complexes of Re, Mo, W, and 0 s " has shown a linear correlation between absolute i.r. intensities of nitrogen bands and the frequencies v(N,). It was suggested that the intensity of v(N,) is largely determined by the extent of n electronic charge transferred from the metal to nitrogen during the N, stretching motion. This leads to the potentially valuable implication that M-N, complexes with large i.r. intensities are those most likely to interact with Lewis acids e.g. reducing agents.' l 2 Nitrosyl complexes. The new cationic species [Os(NO)(CO),(PPh,),] has been isolated as its BPh, salt from the reaction of CO and NaBPh, with [Os(NO)(CO)(PPh,),Cl]. The complex undergoes an interesting reversible reaction with methoxide ion: +

MeO-

[Os(NO)(CO),(PPh3)2]'

[Os(NO)(CO)(COOMe)(Pph,),l

A good demonstration of the relative strengths of M-N and M-C bonds in 0 s and Ru compounds was provided by the reaction with chlorine, which yielded cis-[Os(CO),(PPh,),Cl2], whereas the Ru analogue gave [Ru(NO)(PPh3)2C13].51 The above [Os(NO)(CO),(PPh,),]+ cation has been independently prepared by a similar method, and some reactions reported. Of particular interest, an unusual oxidation of co-ordinated NO was observed with oxygen and excess RNC yielding the complex [Os(NO,)(CO)(PPh,),(CNR),] +. An X-ray analysis showed trigonal-bipyramidal geometry with a linear NO group (see Table 2 ) . I l 3 Convenient syntheses of the species [OsX,(NO)(AR,),] (X = Cl, Br, or I: A = P, R = alkyl, aryl, or alkylaryl; A = As, R = Ph) have been reported involving the use of the reagent N methyl-N-nitrosotoluene-p-sulphonamide.A mechanism was proposed involving the 0s" hydrides [OsX,H(AR,),] as interrnediate~.~, Other nitrogen donor ligands. A series of complexes of the unusual 1,3-dip-tolyltriazenido ligand (L) (9) has been prepared, including [OsH(CO)(PPh,),L]. The i.r. spectrum of the diamagnetic, air-stable complex indicates bidentate co-ordination of L.62 Phosphorus donor ligands. A general synthesis has been reported for cationic

112

D. J. Darensbourg, Inorg. Chem., 1971,10,2399. D. J. Darensbourg, Inorg. Chem., 1972, 11, 1436. G. R. Clark, K. R. Grundy, W. R. Roper, J. M. Waters, and K. R. Whittle, J.C.S. Chem. Comm., 1972, 119.


372

trialkylphosphite complexes of noble metals, including [OsXL,]+ P(OMe), or P(OEt),; X = C1 or Br].82

[L =

Group ZV Donors. A 'H n.m.r. study of the cis-trans isomerization of [Os(CO),(SiMe,),] indicates that the process is non-dissociative. These species may therefore provide a rare example of stereochemical non-rigidity in nonchelate octahedral complexes. Similar non-rigidity was observed for [Os(CO),(SiMeCl,),] and [Os(CO),( SnMe3),].89 Osmium(1rr).-No new complexes have been reported. An investigation of the magnetic susceptibility of OsC1, has resulted in lower magnetic moments and greater temperature dependence than previously found for [osc16]2-. This is attributed to the fact that OsC1, is not a magnetically dilute compound."4 X-Ray powder pattern studies of an extensive range of [M(A-A)2X2]"+ complexes [M = Cr, Co, Rh, Os, Ir, or some of these; A-A = bipy or phen; X, = CI,, ox, (H,O),, or (H,O)(OH)] have shown that they all possess a cis-configuration.' Osmium( ~v).--Group VII Donors. Simple syntheses of hexafluoro-complexes of some noble metals have been reported, e.g. K,[OsX,]

+6

K H F , a K,[OsF,]

+ 6KF + 6HX (X = Cl, Br, or I)

This method has the advantage of not requiring corrosive reagents such as fluorine or BF,.Il6 The diffuse reflectance spectrum of the above complex has been recorded between 4 and 50 cm- permitting calculation of the crystalfield parameters D,, and B, and of the spin-orbit coupling constant. Similar studies of the [0sX6I2- (X = C1, Br, or I) also revealed bands due to transitions between spin-orbit split components of the 3T1, ground state. The extent of covalency was shown to increase in the order F < C1 < Br < Measurements of the magnetic susceptibility of OsCI, show a higher magnetic moment p, and a smaller temperature dependence than previously observed for [osc1(j]2-.' l 4

Group V I and V Donors. A spectroscopic study of a series of metal complexes including [Os(OH),L,],of the ligand 8-amino-7-hydroxy-4-methylcoumarin, 3 H 2 0 ,suggests a correlation between certain vibrational bands, e.g. vaSy,(NHZ), v(M-N), and the stability of the compounds.40 A similar i.r. investigation of a range of complexes of dimethylaminoethanethiol, has shown that the ligand is bidentate in Na[Os(OH),L], co-ordinating via both S and N donors."* The dihydrido-species [OsH2(en),12+ has been prepared inadvertently during the attempted reduction of [OsO2(en),l2+ to 0s":

'I5 'I6

'I8

V. I. Belova and I. N. Semenov, Russ.J . Inorg. Chern., 1971, 16, 1527. P. I. Andersen and J. Josephsen, Acta Chern. Scand., 1971,25, 3255. W. Preetz and Y. Petros, Angew. Chern. Internat. Edn., 1971, 10, 936. G. C. Allen, R. Al-Mobarak, G. A. M. El-Sharkawy, and K. D. Warren, Znorg. Chern., 1972, 11, 787. P. C. Jain, D. K. Rastogi, and H. L. Nigam, Indian J. Chern., 1971,9, 1308.

The Noble Metals

373

K2[OsO2(OH),]

+ (en),2HCl

Hzo * [OsO,(en),]C1, Ar

1

(new complex)

Zn-Hg HC1

[OsH,(en),]ZnCl,

This yellow, diamagnetic complex provides one of the few examples of metal hydrido compounds which contain only saturated ammine ligands.' Osmium@).-Further Osv-arylimido-complexes have been synthesized via the reaction of phosphinimines with [OsOC1,(PPh3),] :

'

[OsOCl (PPh 3) 2 ]

+ Ph P=NCOC 6H,R

, ,

[Os(NC,H R)Cl (PPh 3) 2]

3

These paramagnetic, air-stable complexes could equally well be formulated arylnitrenes.' 2o Both crystal-field and charge-transfer bands have as O S ' ~ been observed in the diffuse reflectance spectrum of [OsF,]-. Calculation of the spin-orbit coupling constant and crystal-field parameters indicated that the degree of covalency is high for a fluorocomplex, and comparable with that found for quadrivalent [MF,I2- species of the first transition series.12 Osmium(vI).-The i.r. spectrum of [0sOCl4] has been recorded in the gas and liquid phases, and in solution. While the exact geometry could not be deduced, evidence was obtained for facile co-ordination of acetone or ether to the species in inert solvents.'22 A mass spectral study of this complex reveals a complex fragmentation pattern, including the previously unknown [OsOCl,]+ species.' Osmium(vIII).~-From studies of the extraction of OsO, from alkaline aqueous solutions by carbon tetrachloride, it has been suggested that the anion [OsO,(OH)]- may exist in these media. Similar evidence was found for the Examinapresence of [OsO,N]- in aqueous ammonia solutions of OsO, tion of the i.r. spectra of a series of metal complexes of the ligand 8-amino-7hydroxy-4-methylcoumarin, including [Os02L2]C12, indicate a correlation between certain vibrational bands, e.g. v(M-N), and the stability of the

corn pound^.^^

r

c1

0

o+II

e-

7

I

--------Sn-Cl

I

'I9 120 12' 122

123 124

J. Malin and H. Taube, Inorg. Chem., 1971, 10, 2403. J. Chatt and J. R. Dilworth, J.C.S. Chem. Comm., 1972, 549. G. C. Allen, G. A. M. El-Sharkawy, and K. D . Warren, Inorg. Chem., 1972, 11, 51 C. G. Barraclough and D. J. Kew, Austral. J . Chem., 1972,25,27. D. L. Singleton and F. E. Stafford, Znorg. Chem., 1972, 11, 1208. D. A. Lee, J . Inorg. Nuclear Chem., 1972,34, 375.


374

Table 2 X-Ray data for osmium compounds Compounds EO~,(M~CO,),(CO),I

R 0.089

[OS(NO)(CO),(PPh,),]C104

0.054

[HOs(CO),(PPh,)(PPh,C,H4)]

0.049

[Os,(CO),(PPh,)(Ph)(PPhC,H,)I

0.05

[Os,(CO),(PPh,),(C,H,)I

0.05

(a) J.

Comments Each 0 s is roughly octahedral. Contains 0s-0s bond, and a cisoid bridging acetate group. Trigonal bipyramid with a linear NO group. Triangular Os, cluster. Contains novel bridging phenyl group between two 0 s atoms. Triangular Os, cluster, bridged by a benzyne fragment. A C--H bond of one PPh, has undergone oxidative addition and formed an 0s-C bond.

RC$ a

h c

c c

G. Bullitt and F. A. Cotton, Inorg. Chirn. Acto, 1971,5,406; (b)ref. 113; (4ref. 107.

An O S ~ ~ ~ ~ - - S charge-transfer ~C~, complex of the type (25) has been proposed as an intermediate in the Os0,-catalysed reduction of Fe"' by [SnCl,]-.'25 3 Rhodium

Cluster Compounds.-Several papers have been published concerning the preparation and chemistry of Rh4(CO),,. A re-investigation of the preparation of Rh,(CO),, from the reaction of CO and NaHCO, on [Rh(CO),Cl],, has shown that the presence of water is essential. However, the amount of water is critical, large quantities causing formation of the alternative product Rh,(C0),,.126 The reaction of Rh(CO),, with phosphine and arsine ligands has yielded the new complexes Rh,(C0)12L1 and Rh4(CO)loLi [L' = PPh,, P(p-MeC,H,),, P(p-FC,H,),, or AsPh,; 2L' = Ph,PC,H,PPh,]. Some of these have been shown to undergo a novel tetramer-dimer interconversion in the presence of free phosphine and excess C O : Rh4(CO),,L:

+ CO

2L'

Rh,(CO),Li

[L2 = PPh,, P(p-MeC,H,),, or P(p-FC6H4)3].Of more fundamental interest was i.r. evidence for the formation of the hitherto unknown Rh,(CO), from the low-temperature (high-pressure) reaction between Rh,(CO),, and C0.'27 Whereas Rh,(CO),, catalyses the hydroformylation of propene in toluene, the use of more polar solvents such as methanol and acetone has been shown to yield instead Rh,(CO),,, and the first reported acyl clusters [NR,][Rh,(CO),,(COR)] [R = Et(ethy1ene) or Pr(propene)]. The presence of the acyl group was confirmed from the i.r. spectra (1455-1670 cm-').'28 125

I. I. Alekseeva and L. N. Zhir-Lebed, Russ. J . Inorg. Chem., 1971, 16, 587. P. E. Cattermole and A. G. Osborne, J . Organometallic Chem., 1972, 37, C17. R. Whyman, J.C.S. Dalton, 1972, 1375. P. Chini, S. Martinengo, and G. Garlaschelli, J.C.S. Chem. Comm., 1972,709.

375

The Noble Metals

Rhodium(I).--Group VII Donors. Halogeno-carbonyl and -phospAine complexes. Convenient atmospheric pressure syntheses have been reported for the complexes [RhCI(PF,),], and [Rh(acac),(PF,),], by replacing olefins from suitable substrate complexes, e.g. CRhCl(C,H,,),I,

+ PF,

[RhCl(PF,),I, (100%)

These complexes undergo some interesting reactions including those shown in Scheme 11. Compound (26) contains a Rh-Hg bond, while Rh,(PF,), is

believed to have a structure similar to that of the isomer of Co,(CO), without bridging CO groups.'29 An alternative route to [RhX(PF,),], (X = C1, Br or I) has also been described involving treatment of [RhX(CO),], with excess PF,. The use of smaller quantities of PF, yielded the series [Rh,Cl,(PF,),( C O ) ~ - X(x ] = 1,2, or 3), whereas large excesses gave the unstable yellow [RhX(PF3)4]. ''F N.m.r. studies of some of these indicated rapid exchange of the PF, ligand~.',~" A re-investigation of [RhCl(CO)(PPh,),], has confirmed' 30 the dimeric structure recently p r ~ p o s e d . ' ~ During ' the course of these studies, mixed complexes of the type trans-[RhCl(CO)(PPh,)L] (L = AsPh,, SbPh,, py, Me,S, etc.) were obtained by refluxing with excess L in benzene. The transconfiguration was assigned from i.r. data.' Other new unidentate phosphine complexes to be reported were [Rh(CO)C1(AMe,PhCH2)2] (A = P or As),',, and trans-[RhCl(CO)(PBu\R),] (R = Me, Et, or Pr").',, The latter complex was isolated from the prolonged reaction of tertiary t-butylphosphine with RhC1,,3H20 in ethanol. The stereochemically interesting ligand l,l,l-tris(diphenylphosphinomethy1)ethane (27) has been shown to form complexes of the type [RhCl(CO)L] which are mixtures of four- and five-co-ordinate

,'

,CH ,PPh MeC -CH,PPh,

'CH,PPh,

(27) M. A. Bennett and D. J. Patmore, Inorg. Chem., 1971, 10,2387. D. F. Steele and T. A. Stephenson, Znorg. Nuclear Chem. Letters, 1971, 7, 877. 1 3 ' R. Poilblanc and J. Gallay, J . Organometallic Chem., 1971,27, C53. IJ2 R. L. Bennett, M. I. Bruce, and F. G. A. Stone, J . Organometallic Chem., 1972,38,325. lJ3 C . Masters and B. L. Shaw, J.C.S. Dalton, 1972, 3679. lZ9

lJO


376

isomers (i.e. L is either bi- or ter-dentate) both in solution and as s 0 1 i d s . l ~ ~ Complexes of another chelate phosphine ligand, PhP(C,H,PPh,),, have been prepared :

The reaction of these yellow square-planar complexes with small molecules was shown to yield stable five-co-ordinate adducts of the type [RhClLA] (A = BF,, CO, HgCl,, SO,, O,, S,, H + , NO', or N,Ph+). 1.r. measurements confirmed the presence of co-ordinated BF,, and supported symmetrical x-bonding of the 0, and S, complexes (28). The greater stability of these adducts

compared to those with other non-chelating phosphines, together with the simplified product geometries, suggests that terdentate phosphine complexes of this type may offer great potential for future studies.'35 A fascinating development has been the independent reports from two laboratories of resin-bound transition-metal complexes. An i.r. study of the bridge-splitting reactions of [RhCI(CO),], with a range of ion-exchange resin polymer ligands showed that complexes of the type cis-[RhCl(CO),(resin-L)] were initially formed for both tertiary amine and phosphine polydetailed investigation of the polystyrene resin Biobeads m e r ~ . 'A~ more ~ SX-2 (29) with various Rh complexes led to the isolation of complexes of the

t y p [RhCl(CO),(P-resin)] and [RhCl(P-resin),], together with some polynuclear complexes. In the complex [RhCI(P-resin),], the resin is functioning as a chelate.'j7 In view of the recent application of resin-bound complexes as heterogeneous catalysts,' 38 the efficiency of [RhCl(P-resin),] as a hydrogenation catalyst was tested, and found to be superior to that of homogeneous

analogue^.'^' 134

13'

138

W. 0. Siegl, S . J. Lapporte, and J. P. Collman, Inorg. Chem., 1971, 10,2158. T. E. Nappier and D. W. Meek, J . Amer. Chem. Soc.. 1972,94,306. L. D.Rollmann, Inorg. Chim. Acra, 1972,6, 137. J. P. Collman, L. S. Hegedus, M. P. Cooke, J. R. Norton, G . Dolcetti, and D. N. Marquardt, J . Amer. Chem. Soc., 1972,94,1789. W. 0. Haag and D. D. Whitehurst, Belg. Patent, 1969,721, 686.

The Noble Metals

377

Two reports confirm Schriver's' 39 recent demonstration that the catalytically important [RhCl(PPh,),] is essentially undissociated in solution. A spectral study in dilute oxygen-free benzene solutions gives values of lop4 mol 1-' for the dissociation constants of [RhX(PPh,),] (X = C1, Br, or I).'40 Similarly, re-investigation of the 31P n.m.r. of [RhCl(PPh,),], and also of [RhCl(P(p-tolyl),),], in dichloromethane is consistent with the presence of 6 3 % free phosphine. In addition, 'H and ,'P n.m.r. studies of the addition of hydrogen gas to [RhCl(PPh,),] showed that the hydride formed was not five-co-ordinate as previously suggested, but octahedral with configuration

-

(30).'

c1, Ph,P'

H

I ,PPh

Rh

IH'

PPh, (30)

A comprehensive i.r. investigation of the reaction mixtures obtained from the reaction of phosphines with [RhCl(CO),], has established that the systems are composed of two series of complexes: (i) mononuclear complexes X,, [RhCl(CO),-,L,] ( n = 1, 2, or 3)' and (ii) dinuclear complexes Y,, [Rh,Cl,(m = 0, 1, 2, 3, or 4),[L = PPh,, PMe,Ph, or P(Me,NH),]. The (CO),-,L,] new complexes Y, and Y, were sufficiently stable to isolate, but other new compounds were confirmed by physical means. Their 'H n.m.r. spectra indicate rapid and complex ligand e~change.'~' Examination of the i.r. spectra of trans-[RhX(CO)(PPh,),1 has shown that the frequency of the o,(RhCO) vibration decreases in the order X = F > C1 > Br > I, corresponding to an increase in the Tc-acceptor power of the trans ligand.14, Meanwhile, a theoretical treatment of the CO stretching vibrations of several dinuclear metal carbonyls, including [RhX(CO),], (X = C1, Br, or I), indicates that the intermolecular coupling and other interactions between CO groups are principally due to dipole-dipole forces.26 Comparison of the 31P n.m.r. spectra of trans-[RhCl(CO)(PBu',R),] (R = Me, Et, or Pr") at room temperature and -60 "C has shown that they exist as rotational conformers. The calculated energy barrier to rotation about the Rh-P bond of several kcal mol-' clearly indicates the significant steric effect of these bulky general investigation of the 31Pn.m.r. spectra phosphine l i g a n d ~ . 'A~ more ~ of phosphine complexes, including trans-[ RhCl(CO)L,], has revealed a good correlation between the chemical shift of the free phosphine and the change 140

14'

143 144

D. D . Lehman, D. F. Schriver, and I. Wharf, Chem. Comm., 1970, 1486. H. Arai and J. Halpern, Chem. Comm., 1971, 1571. P. Meakin, J. P. Jesson, and C. A. Tolman, J . Amer. Chem. SOC.,1972, 94,3240. J. Gallay, D. De Montauzon, and R. Poilblanc, J . Organometallic Chem., 1972, 38, 179. Y. S. Varshavskii, M. M. Singh, and N. A. Buzina, Russ. J . Inorg. Chem., 1971, 16, 725. B. E. Mann, C. Masters, B. L. Shaw, and R. E. Stainbank, Chem. Comm., 1971, 1103.

378


in chemical shift on ~o-ordination.,~[RhCl(PPh,),] has been reported to catalyse. hydrogen-deuterium exchange between D, and moleculesasuch as acetic acid, methanol, ethanol, and morphine.36The preparation of many new complexes of the type [RhCI(PR),] and [RhCl(CO)(PR),] [R = Me,, Et,, Pr:, Bu", Oct;, Pr;, Bu;, (cyclohexyl),, Bz,, Me,Ph, Et,Ph, MePh,, or EtPh,] have ,been reported, together with 'H n.m.r. and i.r. structural ~ t u d i e s . ' ~ '

Group VZ Donors. Oxjyen donor ligands. The chiral complex [RhL,(tfacCam)] (31) of the asymmetric ligand ( -)-3-trifluoroacetylcamphorate has been prepared via the reaction of Ba(tfacCam), with [Rh2Cl,L,] (L = CO, C,H,, $cod, or inorbornadiene). 1.r. and 'H n.m.r. studies of these optically active,

CF, (31)

air-stable complexes indicate structures closely related to the analogous acetylacetone species.'46 Other workers have measured the first ionization energies of a range of P-diketonato-complexes of the type (32) [R', R2 = Me, CF,, Ph, and mixtures; M = Rh, Rh(CO),. or Ir(CO), : n = 3 or 11. Ionization

-"3 R'

' C -

' p

*

was postulated to OCCUT from a molecular orbital with significant participation of the metal atomic 0rbita1.l~' Molecular oxygen adducts. Despite many physical studies, the bond length of co-ordinated oxygen can still be interpreted as either superoxide (or peroxide) ion, or an electronically excited state of molecular oxygen. In order to establish the bond character more clearly, a 1 7 0 n.m.r. study has been carried out on several complexes, including [Rh(02)(Ph2PC2H,PPh2)]Cl. Unfortunately, no resonance attributable to 1 7 0 2 could be found, suggesting that Vaska type complexes tumble at a rate which broadens the resonances beyond '45

14'

G . M. Intille, Inorg. Chem., 1972, 11, 695. V . Schurig, Inorg. Chem., 1972, 11, 736. F. Bonati, G . Distefano, G. Innonta, G. Minghetti, and S. Pignatoro, Z . anorg. Chem., 1971, 386, 107.

The Noble Metals

379

dete~tion.'~'An " 0 isotopic i.r. study has been carried out on a number of oxygen complexes, including [Rh(O,)(Bu'NC)XL,] (X = C1 or Br; L = PPh, or AsPh,). The results confirm oxygen co-ordination to be a side-on isosceles structure in the Rh complexes. Assignment of the Rh-0 stretching vibration was made for the first time, and from the overall study the M-0 stretching force constants were correlated with the reactivity of the 0,ligand.'49 Group V Donors. Nitrosyl Complexes. The new dark-brown complex [Rh(NO)Cl(AsPh,),] has been prepared:

The reaction was found to be reversible by refluxing the Rh-NO complex ' syntheses have been reported in DMF, or bubbling CO t h r 0 ~ g h . l ~Improved for a range of hydrido, carbonyl, and nitrosyl complexes of the noble metals, including the new [Rh(NO)L,] [L = P(p-Cl,H,), or P(p-MeC,H,),]. This method involves the use of ethanolic KOH or NEt, as a basic reducing reagent under homogeneous conditions,22" rather than the NaBH, previously employed.22b Nitrogen 1s binding energies have been determined by X-ray p.e. spectroscopy for [RhWOM'Ph,),], [Rh(NO)2(PPh3)2]PFcj, [RhX,(NO)(PPh3)2] (X = C1 or I), and several other metal-nitrosyl complexes. Among the several interesting conclusions arising from this study were: (i) bent NO groups have low binding energies: (ii) although linear NO groups can have a range of energies, there is a rough correlation between v(N0) and binding energies: and (iii) terminal and bridging NO groups apparently have the same electron densities since they are indistinguishable by this method.,' In an unusual study, the structure of [Rh(NO)(PF,),] has been determined in the gas phase using electron diffraction ( R = 0.15). A linear R h - N 4 grouping is indicated.' 5 1 Other nitrogen donor ligands. Complexes of the type [Rh(L-L)A,] (L-L = acac or 8-hydroxyquinoline; A 2 = py2, phen, or bipy) and [Rh(L-L)(py),] have been reported from the action of the nitrogen heterocycle on [Rh(L-L)(CO)2].15 2 A re-investigation of the related reaction of 2,2'-bipyridyl with [RhCl(CO),], has given a series of complexes containing Rh-bipy-Rh bridges, whose composition depends on the ratio of reagents employed. Bipy:Rh ratios of 1:5, 1:3, and 1:6 yielded the compounds [(CO),ClRh(bipy)RhCl(CO),], [(CO),ClRh(bipy)RhCl(CO),(bipy)], and [(bipy)(CO),ClRh(bipy)RhCl(CO),(bipy)], respectively. These complexes are either fouror five-co-ordinate about Rh, the last two containing unidentate bipyridyl 14* 149

t52

A. Lapidot and C. S. Irving, J.C.S. Dalton, 1972, 668. A. Nakamura, Y. Tatsuno, M. Yamamoto, and S. Otsuka, J . Amer. Chem. SOC.,1971,93, 6052. Y. N . Kukushkin, L. I. Damlina, and M. M. Singh, Russ. J . Znorg. Chem., 1971, 16, 1449. D. M. Bridges, D. W. H. Rankin, D. A. Clement, and J. F. Nixon, Acta Cryst.. 1972, B28,1130. Y. S. Varshavskii and T. G. Cherkasova, Russ.J . Znorg. Chem., 1971, 16, 1384.

Inorganic Chemistry of Transition Elements

380

ligands.I5, Other bipyridyl complexes reported are [Rh(CO),(bipy)]ClO,, [RhH2(PPh3),(bipy)]C104, and [Rh(CO)(PPh,)2(bipy)]C104.1 54 Reaction of mer-[RhCl,(PMe,Ph),] with dibenzoylhydrazine in refluxing ethanol (in the presence of NaHCO,) has given the novel dimer [(PMe,Ph)(C0)Rh-N+COPh)],. Although no evidence is given, a structure was suggested involving dibenzoyldi-imide acting as a quadridentate bridging ligand.' 5 5 Dicyanoketiminato complexes of the type [Rh(C,N,)(CO )( APh,),] (A = P or As) have been prepared via the metathetical reaction between K(C,N,) and trans-[RhCl(CO)(APh,),]. The i.r. spectra of these compounds support N-bonding of the ligand (33; M = Rh).156 APh

CO-M

I I

-N=C

=C

,CN \

CN

Nitrogen Is binding energies have been determined by X-ray p.e. spectroscopy for [Rh(CO),(N,)],, together with some other metal azides. The similarity of their spectra to that of sodium azide suggests that the internal bonding of N, is little affected by co-ordination i.e. the Rh-N, bond is essentially ionic5' Phosphorus donor ligands. Convenient syntheses have been described for an extensive series of diphenylphosphine complexes, including the salt [Rh(HPPh,),]+. This complex is similar both in structure and reactivity to the bis(ditertiaryph0sphine) analogue.,' Dimeric complexes of the type [Rh,(CO),(PPh,)(O,CR),] (R = Me or Et) have been prepared from the reaction of the triphenylphosphine with hexane solutions of [Rh(CO),(O,CR)],. The i.r. spectra of these dark-brown, air-stable solids shows the presence of bridging 0,CR groups (1588s, 1440s cm- I). If excess triphenylphosphine was employed the monomer [Rh(CO)(PPh,),(O,CR)] was isolated whose spectra suggested bidentate 0 2 C R g r o ~ p s . ' ~Similar, ' but apparently monomeric, complexes [Rh(OCOR)(PPh,),] have been reported in high yields from the treatment of the dirhodium cation Rh;' with methanolic solutions of Li(OC0R) and triphenylphosphine (R = Me, Et, Pr, C S H l l , Ph, CH2Cl, CClF,, CF,, or C,F,). Their chemical properties are similar to those of [RhCl(PPh3)3].158 An interesting paper reports the synthesis of the new series of cationic com(M = Co, Rh, or Ir; 2-phos = cis-Ph,PCH= pcunds [M(Zphos),]A CHPPh,: A = C1, I, BF,, or BPh,). The reactions of these complexes with Y. S. Varshavskii, N. V. Kiseleva, and N. A. Buzina, Russ. J . Znorg. Chem.. 1971, 16, 862. C. Cocevar, G. Mestroni, and A. Camus, J . Organometallic Chem., 1972,35, 389. ' 5 5 F. M. Hussein and A. S. Kasenally, J.C.S. Chem. Comm., 1972, 3 . M. Lenarda and W. H. Baddley, J . Organometallic Chem., 1972,39,217. "' C.Csontos,B. Heil, and L. Marko, J . Organometallic Chem., 1972,37, 183. 1 5 8 R. W. Mitchell, J. D. Ruddick, and G. Wilkinson, J.C.S. Dahon, 1972, 3224.

lS3

154

38 1

The Noble Metals

covalent molecules : [M(2-phos),]A

+ XY + [M(2-phos),XY]A

(XU = O,, H,, HCl, CO, or SO,)

provides the first direct comparison of the reactivities of planar d8 complexes of three different metals in a triad. The reactivity order observed was Co > Ir > Rh.I5' Other interesting complexes are the unusual [Rh(CO),(PPh,),HgPh], [Rh(CO),(PPh,),Hg(p-tolyl)], and [Rh(CO),(PPh,),],Hg, containing Rh-Hg bonds, which have been reported from the oxidative addition of RHgCl to suitable Rh-' substrates. 'H N.m.r. and i.r. data are consistent with the structure (34).',' OC,, IC0 Ph3P- Rh-HgR

I

PPh3 (34)

Addition of NaBH,CN to trans-[Rh(OClO,)(CO)L,] [L = PPh, or P(C,H, 1)3] has yielded the first reported example of a cyanohydroboratocomplex, trans-[Rh(BH3CN)(CO)L2]. Its i.r. spectrum suggests that the BH,(CN)- is N-bonded to Rh. Similar complexes, trans-[Rh(BH,)(CO)L,], were obtained using NaBH,, but here spectral data indicate co-ordination through a double H bridge RhH,BH,. One is tempted to suggest that such metal-hydroborato-complexes are intermediates in the well-known synthesis of metal hydrides via reduction with BH, or BH3(CN)-.I6' A general synthetic route has been reported for a wide range of trialkyl phosphite complexes of noble metals, including the unstable white [RhL,] [L = P(OMe), or P(OEt),].82 Subsequent studies have shown that the former complex reacts with NOPF, in dichloromethane to give the hydride [RhH{P(OMe),),](PF,), in high yield.',, +

Group IV Donors. Despite widespread interest in the reactivities of low-valent d8 metal complexes, little attention has been given to isocyanide complexes of Rh'. This situation has been dramatically changed with the appearance of four independent papers on the subject. New isocyanide complexes of the type [Rh(RNC),]+ (R = Me, But, Pr', cyclohexyl, p-CIC,H,, p-MeC,H,, or p-MeOC6H,) have been isolated from the reaction between free isocyanide and a variety of Rh substrates e.g. [RhCl(C0),],.'63-165 'H N.m.r. and i.r. studies of oxidative addition to these compounds shows that the products [Rh(Bu'NC),XY]BF, (XY = I,, MeI, EtI, PrI, BuI, PhCH,I, or PhCH,Cl) Other workers have come to the same stereochemical are all trans 0ctahedra1.l~~ 160 16' 162 163 164 165

L. Vaska, L. S. Chen, and W. V. Miller, J . Amer. Chem. SOC.,1971,93,6671. G. M. Intille and M. J. Braithwaite, J.C.S. Dalton, 1972, 645. L. Vaska, W. V. Miller, and B. R. Flynn, Chem. Comm., 1971, 1615. R. H. Reimann and E. Singleton, J . Organometallic. Chem., 1971, 32, C44. P. R. Branson and M. Green, J.C.S. Dalton, 1972,1303. A. L. Balch and J. Miller, J . Organometallic Chem., 1971, 32, 263. J. W. Dart, M. K. Lloyd, J. A. McCleverty, and R. Mason, Chem. Comm., 1971, 1197.

382


conclusion for the oxidative addition of bromine and iodine to the analogous trans-[Rh(RNC),L,]+ complexes (R = p-MeC,H,, p-MeOC,H,, or p-cIc,H,; L = PPh, or PMePh,).I6, These studies represent the first examples of oxidative addition to isocyanide complexes, and suggest a common trans addition mechanism. Other new isocyanide complexes reported include [RhC1(PPh,)2(CNMe)],'64 and [Rh(PPh,),(CNR),]Cl (R = But, Pri, pClC,H,, or p-MeC,H,),'65 together with their oxidative addition products. A general route to the complexes [RhL(PF,),] [L = SiPh,, Si(OEt),, SiCI,, or GePh,] has been reported, involving the addition of LH to the new compound Rh,(PF,), (see above).'29 Also described are the halogenotin compounds [Rh(CO)(SnX,)X,]2- (X = C1 or I) and [Rh(CO)(SnX,),XI2and [Rh(CO)(SnX,),I2- (X = C1 or Br), obtained by reacting halogenocarbonylrhodium solutions with the respective tin@) halides in ethanol.' 6 5 Rhodiurn(i1). --This generally unstable oxidation state is attracting increasing attention. The new black Rh"-glyoximato-complex, [Rh,(OCOMe),(dmg),(H20),], has been isolated from the reaction between [Rh,(OCOMe),(H,O),] and dimethylglyoxime. Treatment of this complex with triphenylphosphine yielded the analogous red [Rh,(OCOMe)2(dmg),(PPh3)2 ],H,O. An X-ray analysis of the latter compound (see Table 3) confirms a short Rh-Rh distance (2.618 A) and shows the presence of acetate bridges (35).',* Magnetic susceptiMe

(35)

bility measurements of the related acetato-complexes [Rh,(OCOMe),L,] [L = H,O, NH,, py, N,H,, PPh,. CO(NH,),, CS(NH,),. Or C,H,(NH,),], K,[Rh,(OCOMe),X,], and K,[Rh,(OCOMe),X,] (X = CI, Br, or NO2),

\ / CH,-CH,

166

16'

R. V. Parish and P. G. Simms, J.C.S. Dalton, 1972, 809. J. V. Kingston and G. R. Scollary, J . Chem. SOC.( A ) , 1971, 3399. J. Halpern, E. Kimura, J. Molin-Case, and C. S. Wong, Chem. Comm., 1971, 1207.

The Noble Metals

383

have shown that they are all diamagnetic. Similar results were obtained for [Rh2(0COR),L,] (R = CH,C1, CCl,, or CF,; L = H,O or EtOH).16' The reaction between methanolic RhC1,,3H20 and the quadridentate Schiff base (36) in the presence of pyridine and zinc amalgam has been shown to give a variety of products, including a species tentatively formulated as [Rh(~alen)py],.'~~ Another complex tentatively assigned as Rh" is the super0x0 species [Rh(O,)Cl,(DMA),,] observed in the e.s.r. spectrum of oxygenated solutions of [RhCl(C,H,,),], in NN-dimethylacetamide containing LiC1.17' As part of a continuing study of bulky t-butylphosphine complexes, Shaw et al. have shown that these ligands can stabilize the Rh" oxidation state. RhC1,,3H20 reacted rapidly at room temperature with ethanolic PBu',R to yield complexes trans-[RhCl,(PBu',R),] (R = Me, Et, or Pr"). These compounds have low magnetic moments ( c1.4 BM) as solids, but show the expected values (2.1 BM) in solution.172 Rhodiurn(II1).-Group VII Donors. Hydrido-complexes. The monohydridocomplexes [RhHCl,L,] (L = PBu'Pr,, PBu\Me, PBuiCl, or PBuiPr) have been prepared by refluxing solutions of RhC1,,3H20 and free phosphine in propan-2-01. A preliminary communication has appeared. It is interesting that the use of other solvents and conditions allowed the isolation of Rh' and Rh"' complexes also.' 72 Treatment of [RhCl(CO),], in dichloromethane with POMePh,, followed by protonation with HX, has been shown to yield the hydrides [RhHCl(POMePh,),]HX, (X = C1, or CF,CO,). The presence of the Rh-H bond was confirmed from 'H The preparation and spectral properties of complexes of the type [RhHCl,L,], [RhH,ClL,], and [RhHCl,(CO)L,] (L = PMe,, PEt,, PBu,, POct,, PPr,, PPr;, PBu;, P(C6HI1),, PBz,, PMe,Ph, PEt,Ph, PMePh,, or PEtPh,] have been r e ~ 0 r t e d . l ~ ' Halogeno-carbonyl and -phosphine complexes. A re-investigation of the reaction of NaI with 'RhCOI' solutions has shown that the complex isolated by addition of Et,NCl and previously formulated as cis-(Et,N)[Rh(CO),I,], is actually (Et,N),[Rh(CO)I,]. Similarly, the supposed trans-(AsPh,)[RhRussian workers (C0),I4] is now found to be (ASP~,)[R~(CO)(E~OH)I,].~~ have reported further confirmation of the carbonylating ability of the solvent dimethylformamide, in its reaction with RhCl, to yield (Bu~N)[R~(CO)~CI,].' Other new complexes to be described were mer- and .fac-[RhCl,(PR,),], [RhCl,(PR,),],, [RhCl,(CO)(PR,),] (PR, = wide range of tertiary phosphine~),',~and the monomeric [RhCl,(AMe,PhCH,),] (A = P or As).132 'H N.m.r. and i.r. spectral data were employed to suggest structures. Comparison of the o,(RhCO) frequencies in [Rh(CO)(PPh,),XY,] (X = 169

'*

17' 17'

173 174

V. I. Belova and Z. S. Dergacheva, Russ.J . Inorg. Chem., 1971,16, 1626. R. J. Cozens, K. S. Murray, and B. 0. West, J . Organometallic Chem., 1972,38, 391. B. R. James, F. T. T. Ng, and E. Ochiai, Canad. J . Chem., 1972, 50, 590. C. Masters and B. L. Shaw, J.C.S. Dalton, 1972, 3679. P. C. Kong and D. M. Roundhill, Znorg. Chem., 1972,11, 1437. I. B. Bondarenko, N . A. Buzina, Y. S. Varshavskii, M. I. Gel'fman, V. V. Razumovskii, and T. G. Cherkasova, Russ. J. Znorg. Chem., 1971, 16, 1629.

384


F, C1, Br, or I; Y, = Cl,, Br,, or I,) with those of the Rh' complexes trans[Rh(CO)(PPh,),X], reveal their sensitivity to both X and the oxidation state of the metal [o,(RhCO) decreases with increasing oxidation ~ t a t e 1 . lThe ~~ conflicting structures proposed in the literature for [Rh,Cl,(PBu,),] from 'P n.m.r.' 7 5 and dipole moment '" data have been resolved by a re-examination of this complex. The reported preparation was shown to yield a mixture of the desired compound and [Rh,Cl,(PBu,),] and mer-[RhCl,(PBu,),]. 1.r. and 'H n.m.r. data on the pure [Rh,Cl,(PBu,),] suggested the structure (37) which is consistent with the dipole moment (10.5

c1 Bu 3p\Rh/

I

C1\

Bu3P/I 'Cl'I

c1

PBu~ / Cl Rh

I

\C1

PBu~

(37)

More comprehensive 'P n.m.r. studies of a range of noble metal phosphine complexes, including mer-[RhCl,L,] (L = wide choice of tertiary phosphine), have shown a correlation between the 31Pchemical shift of the free phosphine and the change in chemical shift on co-ordination. The effect of changing the halide ligand on the 31Pchemical shift was also studied.j7*1 7 * Group V I Donors. Oxygen donor ligands. A new and more successful preparation of cis- and tr~ns-K[Rh(ox),(H,O)~]has been reported, via the chromatographic separation of the acid hydrolysis products from K,[Rh(ox),],4$H20."' The u.v.-visible spectra of these complexes cast doubts on the purity of the samples previously described.18' An interesting feature of Rh"'-oxalate chemistry is the assertion'" that K3[Rh(ox),],4$H,O actually exists as the This has now partly unidentate K,[Rh(ox),][Rh(ox),(C204H)(OH)],8H,0.

T.H.Brown and P. J. Green, J . Amer. Chem. SOC.,1970,92,2359. J. Chatt and B. L. Shaw, J . Chem. SOC.,1964, 2508. F. H. Allen and K. M . Gabuji, Inorg. Nuclear Chem. Letters, 1971, 7, 833. 17' B. E. Mann, C. Masters, and B. L. Shaw, J.C.S. Dalton, 1972, 704. 1 7 9 N.S. Rowan and R. M. Milburn, Inorg. Chem., 1972, 11, 639. R. D. Gillard and G. Wilkinson, J . Chern. SOC.,1964,870. ' * l a A. L. Porte, H. S. Gutowsky, and G. M. Harris, J . Chem. Phys., 1961,34, 66. 181b D.Barton and G. M. Harris, Znorg. Chem., 1962, 1, 251. 17'

176

"'

The Noble Metals

385

been refuted in the solid state by an X-ray analysis (see Table 3) which shows that all the oxalate ligands are strictly bidentate.lS2 Oxidative addition of tetrachloro-1,2-benzoquinoneto [Rh(CO)(PR,),CI] (R, = Ph, or Ph,Me) or to [RhCl(PR,),] has been shown to give the Rhtn products [Rh(l,2-O,C6C1,)(Co)Cl(PR3),] (38), and [Rh( 1,2-02C,C1,)Cl(PPh,),], respectively. Their i.r. spectra confirm the absence of ligand C=O bands, and the trans C1-Rh-4 geometry.ls3 The complexes [Rh(salen)Clpy] and (pyH)[Rh(salen)Cl,] have been prepared in high yield from the reaction of the quadridentate salenH, (33) with methanolic solutions of RhC1,,3H20 containing pyridine and zinc amalgam. Further reduction of [Rh(salen)Clpy] using Na-Hg in T H F gave species tentatively assigned Rho and Rh' oxidation states.'66 The isolation of [Rh,O(OCOMe),(H,O),]ClO4,2H,O from mixtures of RhC1,,3H20 and Ag(OC0Me) in acetic acid has been described. Its structure was confirmed from X-ray powder pattern studies which showed it to be isostructural with [Cr,O(OCOMe),(H,O),]C10,,2H20. The co-ordinated water could be readily displaced by other 84 The successive ligands yielding, for example, [Rh,0(OCOMe)6(py)3]Clo~.1 stability constants have been measured (soIubility method) for the formation of hydroxo-complexes in the aqueous reactions : I s 5 Rh(OH),(S) + OH-

+ Rh(0H);

Rh(OH),(S) + 2 0 H Rh(OH),(S)

+ Rh(0H);+ 30H-+ Rh(0H);-

Sulphur donor ligands. Following a preliminary communication,' 86e a detailed report has appeared of the preparation of the sulphide complexes [RhX,L,] (X = C1, Br, or I; L = Me,S, Et,S, pentamethylenesulphide, or tetramethylenesulphide). I.r.y H n.m.r., and dipole moment studies indicate that they all have a common octahedral mer configuration.' 8 6 b Not surprisingly, the complex recently reported by Russian workers' 87 as fuc-[RhCl,(SMe,),] was also shown to be mer. The red thioacetamide complex [RhCI,(MeCSNH,),] has been isolated from the reaction of Na,[RhCl,] with free ligand. Its i.r. spectrum confirms that the ligand is unidentate 'and co-ordinates via the S atom."' On the other hand, the ligand thiovanol (CH,SHCHOHCH,OH) forms the diamagnetic complex [RhL,], whose u.v.-visible and i.r. spectra indicate an octahedral structure, with bidentate ligands.' 89 The preparation of

'

B. C. Dalzell and K. Eriks, J . Amer. Chem. Soc., 1971,93,4298. Y . S. Sohn and A. L. Balch, J . Amer. Chem. SOC.. 1972, 94, 1144. I. B. Baranovskii, G . Y. Mazo, and L. M. Dikareva, Russ. J . Inorg. Chem., 1971, 16, 1388. B. N. Ivanov-Emin, L. D. Borzova, A. M. Egorov, and S. G. Malyugina, Russ. J . Znorg. Chem., 1971,16, 1474.

186aE. A. Allen, N. P. Johnson, and W. Wilkinson, Chem. Comm., 1971, 804. lssbE. A. Allen and W. Wilkinson, J.C.S. Dalton, 1972,613. 'I3' Y . N. Kukushkin, N. D. Rubtsova, and N. V. Ivannikova, Zhur. neorg. Khim., 1970,15,1328. l e e Y . N. Kukushkin, S. A. Simanova, N. N. Knyazeva, V. P. Alashkevich, S. I. Bakhireva, and E. P. Leonenko, Russ. J . Inorg Chem.. 1971, 16, 1327. la9 H. L. Nigam, V. K. Mathur, and K. B. Pandeya, Indian J . Chem., 1971, 9, 1292.

2B

386


[Rh(sacsac),] (sacsac = dithioacetylacetonate) has been described in detail following an initial report.'" Comparison of its i.r. and * H n.m.r. spectra with corresponding data for the analogous Ni", Pd", and Pt' complexes suggests that a slight depletion of the rc-bonding electron density on the ligand Other new backbone occurs on co-ordination to MI' rather than (L = S,CNEt, complexes reported were the air-stable [Rh(PPh,),L,]BF, or 2-mercaptopyridine), prepared by treating Rh;' with L and triphenylphosphine, although the use of excess Ph,PS,H yielded [Rh(Ph,PS,),(PPh,)]. Conductivity and i.r. data confirm that the diethyldithiocarbamate ligand is bidentate in [Rh(PPh,),(S,CNEt,),].'57 The absence of S-H vibrational bands in the i.r. spectrum of [RhL2(H,0),]C1 (L = dimethylaminoethanethiol) has shown that L is bidentate. Comparison of calculated force constants with those found for other noble metal complexes suggests the stability order Pt" > Rh"' > Co" > Ni"."* Group I/ Donors. Nitrogen donor ligands. A complex believed to be K,[Rh,(OH),(NO,),(NH,),N,] has been isolated in 30'x yield from the reaction of K[Rh(N02),(NH3),] with (NH,),SO, at low pH. The presence of a strong Raman band at 2070 cm- ', which is absent in the i.r. spectrum, supports the Interesting complexes of the presence of a bridging Rh-N,--Rh novel 1,3-diaryItriazenido ligand (9) have been reported, including [RhH,(PPh,),L] and [Rh(CO)(PPh,),L] (L = 1,3-di-p-tolyltriazenido or 1,3diphenyltriazenido). The i.r. spectra of these diamagnetic., highly coloured solids indicate bidentate co-ordination of L.,, Displacement of co-ordinated CO has provided a convenient route to [Rh(NO)CI,(AsPh,),] (Scheme 12); NO -CCI

F4 [Rh(NO)CI(AsPb,),]

[Rh(CO)CNAsPh,), I \

[Rh(CO)Cl,(AsPh,),]

I

[Rh(~O)CI,(AsPh,),] Scheme 12

the reactions are readily reversible by refluxing the nitrosyl complexes in DMF, or bubbling through CO gas.'50 Two independent papers have reported the synthesis of nitrogen-heterocycle complexes of the type [RhCl,(py-X),]'93 (py-X = 3-Etpy, 3-CNpy, 4-Etpy, or 4-CNpy)19, and rrans-[RhY,L,]* (Y = C1 or Br: L = several substituted pyridines. isoquinoline. pyrimidine, pyrazole, thiazole, and substituted imidazoles).' 9 3 , 19, All the compounds were prepared catalytically by boiling RhC1,.3H20 with ethanolic solutions of L. It is interesting that 2-substituted I9O

19'

19' 193

G. A. Heath and R. L. Martin, Chem. Comm., 1969,951. G . A. Heath and R. L. Martin, Austral. J . Chem.. 1971,24,2061. L. S. Volkova, V. M. Volkov, and S. S. Chernikov, RUSS.J . Inorg. Chem., 1971, 16, 1383. C. McRobbie and H . Frye, Austral. J . Chem., 1972, 25, 893. A. W. Addison, K. Dawson, R. D. Gillard, B. T. Heaton, and H. Shaw, J.C.S. Dalton, 1972, 589.

The Noble Metals

387

pyridines did not yield well-characterized complexes, possibly owing to steric hindrance.’ 9 3 A new, high-yield synthesis of trans-[RhCl,(NH,),]Cl has been described, employing tran~-[RhH(NH,),]~’ as an intermediate: [RhCI(NH,),] * +

5[RhH(NH,),]

truns-[RhCl,(NH 3)4]C1

-+

dZn

40,

The bromo- and iodo-analogues were readily obtained by reaction of trans~ [RhC12(NH3)4]+ with NaX, the kinetics of which have been s t ~ d i e d . ”The first penta-ammine Rh”’-organonitrile complexes [Rh(NH,),(RCN)]ClO, (R = Me, Ph, CH,=CH, 0-FC4H6, p-FC6H4, or m-FC,H4) have been reported. The observed increase in v(CN) on co-ordination (50-70 cm-’) indicates bonding to Rh via the N atom. U.v.-visible spectral data suggest that RCN is high in the spectrochemical series for [Rh(NH3)5X]n+,lying between NH, and NO,. This high position is attributed to the polarizability of the RCN co-ordination site.Ig6 The complexes trans-[RhLCl,]+ and [RhLCl,] [L = (39)] have been isolated from the treatment of RhCl, with L(HCl),.

These compounds are good starting materials for a range of new complexes (Scheme 13), which are interesting because of the configurational isomerism arising from the four chiral N centres.Ig7A re-e~amination”~of the reaction of NaCN with [RhCl(CO),], in methanol has shown that the product is [RhLCl,]

‘*’- cis-[RhL(CO),]’ H,O

../

cis-[RhLY,] (Y = C1, Br, or I)

\HX

cis-[RhLX]”+ (X = NO,, ClO,, ox, or 2NCS).

t r a n s - [ R h L C l , ] + L trans-[RhLZ,] (Z = Br, I, or NCS) Scheme 13 19’

lg6

19’ 19*

A. J. Poe and M. V. Twigg, Canad. J . Chem., 1972,50, 1089. R. D. Foust and P. C. Ford, Znorg. Chem., 1972, 11,899. N. F. Curtis and D. F. Cook,J.C.S. Dalton, 1972, 691. R. A. Jewsbury and J. P. Maher, J . Chem. SOC.( A ) , 1971,2847.


388

Na,[RhH(CN),], rather than the [RhH(CNj,(H,0)]2- species previously ~ u g g e s t e d . 'The ~ ~ 'H n.m.r. spectrum also identified three long-lived intermediates, namely [RhCI(CO),(CN)]-, trans-[RhICO),(CN),]-, and [Rh(C0)(CN),I2Several papers have appeared concerning the photochemistry of halopentaammine Rh"' complexes. Irradiation of [RhI(NH,),I2 at crystal-field bands and with 90% has been shown to yield only tran~-[Rh1(H,O)(NH,),1~~, A mechanism involving a square-pyramidal excited-state species with an apical I - was proposed. This result contrasts with earlier studies on on [RhCl(NH,),]' , which yields predominantly [R h(H,O)( NH,),], is photolysis.20' On the other hand, the behaviour of [RhBr(NH,j,]'+ reported to be intermediate. producing both [Rh(H20)(NH3),I3+and trans[RhBr(H,O)(NH,),]". The dual mechanism is explained in terms of two photochemically active excited triplet states, which are of similar energy but differ greatly in geometry (one state must have a long Rh-X bond, whereas the other has a long Rh--NH, bond).", A re-investigation of the photolysis of ( - )-[RhD( - )pdta] (pdta = 1,2-propylenediaminetetra-acetate)has shown that an explanation of204the loss of rotation in terms of aquation of a carboxylate group is incorrect. 'H N.m.r. studies indicate that rotation loss is due to the formation of (40), which is the diastereoisomer of the original complex, +

+

+

Me

-H -H I

and contains an axial methyl group. Recovery of the rotation in the dark is now readily understandable. since the diastereoisomeric form (40) would be expected to be about 3 kcal mol-' less stable than the original complex with the methyl group equatorial.205 The isomorphism of a wide range of bipy and phen complexes of the type [M(phen),X,]"+ (M = Cr. Co, Rh, Ir, or 0 s : X = C1, H,O, or +ox), and [M(bipy),XY]"' [XU = CI, or (OH)(H,O)]. has confirmed that they all have a cis-geometry."5 An unambiguous assignment of the v(N=N) stretch in the arylazo-complexes [RhC1,(PPh3)2(p-XC,H,N=N)] ( X = H. F, Br. CF,. 199

*O0 '01

202

'03 '04 '05

D. N . Lawson, M . J. Mays, and G. Wilkinson, J . Chem. SOC. ( A ) , 1966, 52. T. L. Kelly and J. F. Endicott, Chem. Comm., 1971, 1061. T. L. Kelly and J. F. Endicott, J . Amer. Chem. Soc., 1972, 94, 1797. L. Moggi, Gazzetta, 1967,97, 1089. T. L. Kelly and J. F. Endicott, J . Amer. Chem. Soc., 1972, 94, 278. F. P. Dwyer and F. L. Garvan, J . Amer. Chem. SOC.,1961,83, 2610. G. L. Blackmer, J. L. Sudmeier, R. N. Thibedeau, and R. M. Wing, fnorg. Chem., 1972, 11, 189.

The Noble Metals

389

Table 3 X-Ray data for rhodium compounh Compounds Li,RhH,

R 0.063

Li,RhH5

0.145

0.132 -

0.076

0.073

0.07 1 0.064

Comments R eJ: NaCl type structure indicating U ionic bonding. Evidence of metallic bonding between Li and Rh. NaCl type structure indicating a ionic bonding. Evidence of metallic bonding between Li and Rh. Anion a true cofacial h bioctahedron. Rh-Rh distance = 3.121 A. Octahedral co-ordination. The c relatively long Rh-N distance for NH3 trans to H indicates the strong trans influence of H. Rh co-ordinated to six 0 atoms d of oxalate groups in distorted octahedron. No unidentate oxalates. Structure not K, [Rh(ox)3][Rh(ox)2(C,O,H)(OH)I,8H20 as previously suggested. Only example of five-coe ordinate dinuclear Rho. Rh-Rh distance (2.63 A) is in range of reported Rh-Rh bonds. Distorted octahedron of S atoms f about Rh. Two Rh atoms bridged by the 9 MeCO; ligands. Rh-Rh distance = 2.618 A. Distorted octahedron about Rh atoms.

(a) L. B. Lundberg, D. T. Cromer, and C. B. Magee, Inorg. Chem., 1972, 11, 400; (b) F. A. Cotton and D. A. Ucko, Inorg. Chim. Acta, 1972, 6, 161; (c) B. A. Coyle and J. A. Ibers, Inorg. Chem., 1972, 11, 1105; (d) ref. 182; (e) C. B. Dammann, P. Singh, and D. J. Hodgson, J.C.S. Chem. Cornm., 1972, 586; ( f ) R. Beckett and B. F. Hoskins, Inorg. Nuclear Chem. Letters, 1972,8,683;(9)ref. 168.

OMe, or NEt,) has been made for the first time using Raman and I5N substitution experiments. The v(N=N) frequency decreased with increasing electronOther i.r. studies include donating capacity ofX (in range 1531-1471 ema normal-co-ordinate analysis of the compounds [Rh(NX,),Y]Y, (X = H or D; Y = C1 or Br),,07 and an evaluation of the use of far-i.r. in distinguishing halogenorhodium(~r~) complexes of nitrogen heterocycles. The most informative data are generally obtained with bidentate ligand complexes of the types [Rh(chel),X,]+ and [Rh(chel)X,] - .,08 '06

207

'08

G . W. Rayner-Canham and D. Sutton, Canad. J. Chem., 1971,49, 3994. Y. Y. Kharitonov, N. A. Knyazeva, G. U. Mazo, I. B. Baranovskii, and N. B. Generalova, Russ. J . Znorg. Chem., 1971, 16, 1050. I. I. Bhayat and W. R. McWhinnie, Spectrochim. Acta, 1972,28A, 743.

390

Inorganic Chemistry of the Transition Elements 4 Iridium

Iridium(O).--The first dinuclear trifluorophosphine complex of Iro has been prepared by elimination of H from IrH(PF,),: 2IrH(PF,),

3

1r2(PF3&+ H,

An alternative preparation has also appeared (see below).129The mass spectrum of the yellow, diamagnetic complex confirmed the presence of an Ir-Ir bond. and I9F n.m.r. and i.r. data suggest the structure (41).,09 A more con-

venient synthesis has been described for [Ir,(CO),(PPh,),], involving the treatment of [IrI(CO)(PPh,),] with NaOEt in refluxing benzene.21 Iridium(r).-Group VII Donors. Hydrido-carbonyl and -phosphine complexes Reaction of the above [Ir,(CO),(PPh,),] with hydrogen in benzene has been sh&n to yield solutions of the unstable [IrH(CO),(PPh,)]. This in turn reacts with further hydrogen to yield the new trihydride complex [IrH,(CO),(PPh,)], which has been assigned a fac octahedral geometry (42)210 from i.r. and ‘H H

PPh,

n.m.r. studies. Other workers have found the related trihydride [IrH,(PPh,),] to be a useful starting material for the synthesis of hydrido-phosphite complexes (Scheme 14).,

’’

209 210

T. Kruck, G.Sylvester, and I. K. Kunau, Angew. Chem. Internal. Edn., 1971, 10, 725. L. Malatesta, M. Angoletta, and F. Conti, J . Organometallic Chem., 1971, 33, C43. D. Giusto and G. Cova, Gazzetta, 1971,48,519.

39 1

The Noble Metals

Halogeno-carbony2and -phosphine complexes. Convenient atmospheric pressure syntheses have been found for the new complexes [IrCl(PF,),], and [Ir(acac),(PF3121:

These complexes undergo some interesting reactions, including the sequence in Scheme 11 (M = Ir). Compound (26), Hg[Ir(PF,),],, contains an Ir--Hg bond. 29 The stereochemically interesting ligand l,l,l-tris(diphenylphosphin0methy1)ethane (27) has been shown to react with [IrX(CO)(PPh,),] to give the five-co-ordinate complexes [IrX(CO)L] (X = C1 or N3), in which the ligand is terdentate. In solution one of the phosphorus donor sites dissociates from the Ir.I3, A new route to the phosphite complexes [IrCI(CO){P(OPh),),] has also been reported, together with some of their Perhaps the most interesting new development in this area, however, has been the preparation of resin-bound transition-metal complexes. A study of the reaction of the polystyrene resin Biobeads SX-2 (29) with various Ir compounds has led to the isolation of complexes of the type [IrCI(CO),(P-resin)] and [IrCI(P-resin),]. In the latter complex the resin is functioning as a chelate. It is significant that tests indicate that [IrCl(P-resin),] is a better heterogeneous catalyst than its homogeneous ana10gues.l~~ Interest continues in the oxidative addition reactions of [IrCl(CO)(PR,),] type complexes, and in particular the factors influencing such additions. In a kinetic study of the reversible oxygen uptake by [IrCl(CO)L,] [L = P(c6H 1 1 ) 3 , P(P-CIC6H4),, PPh3, AsPh3, PEtPh2, P(p-MeC6H4)3, P(C4H913, PEt,, or P(p-MeOC,H,),], both the rate of oxygen addition and the stability of the resulting [Ir(O,)Cl(CO)L,] adduct were shown to increase with increasing basicity of L. However, the importance of steric factors was evident from the failure of the P(O-MeC6H4), complex to react with oxygen.'13 A related study of the reaction: [IrX(CO)L,]

+ H,

e [IrX(CO)L,H2]

shows that the rate and equilibrium constant for addition are also dependent on the electronegativity of the halogen X and on the Jr-acceptor strength of L.,l4 In order to assess the imp0rtanc.e of steric effects, a large number of trans-[IrCl(CO)L,] complexes have been prepared in which L are bulky (and very basic) tertiary t-butylphosphines. A subsequent study of the oxidative addition of HCl and PhC0,H to these complexes revealed the following order of extent of protonation for L: PMe,Ph > PBu'Me, > PBu'Et, > PBu'Pr, > PBuiMe > PBuiPr. These results confirm the marked retardation caused by steric hindrance.21 Further confirmation was obtained from more extensive 'I' 'I3

'I4 'I5

E. W. Ainscough, S. D. Robinson, and J. J. Levison, J . Chem. SOC.( A ) , 1971, 3413. L. Vaska and L. S. Chew, Chem. Comm., 1971, 1080. W. Strohmeier, J . Organometallic Chem., 1971, 32, 137. B. L. Shaw and R. E. Stainbank, J . Chem. SOC.( A ) , 1971,3716.


392

studies on the systems trans-[IrX(CO)(PBu'R,),] (X = C1 or Br: R = Me, Et. Pr, or Bu). Whereas the substrates with R = Me will readily add on a wide range of molecules (such as CI,, H,, O,, CCI,, CH,=CHCH,Cl, MeCOCl, CIC0,Me, PhN,C1, or PhSO,Cl), only small molecules form adducts when R = Et, Pr, or Unlike most oxidative addition processes. the reaction of trans-[IrCl(CO)(PMe,),] with the primary halides (43;R = H or D etc., M = Br) has been

M (43)

shown to proceed by a free-radical process. Supporting this conclusion is the rate acceleration by oxygen or radical sources, and the retardation caused by radical scavengers such as hydroquinone. The following mechanism was proposed :, ''

+ Q'(initiator)+ 1r"-Q 1r"-Q + R-BrBr-1r"'-Q Ir' + R' -1r"-R 1r"-R + R-Br Br-Ir"'-R

Ir'

-

+ R' + R'

Detailed studies have also been reported of the ability of the [IrX,(CO),]anions to add a variety of molecules such as halogens, alkyl and acyl halides, mercuric halides, and HI.218 On the other hand, the attempted oxidative addition of nitrate ion on [IrCI(CO)(PPh,),] using AgNO, led instead to the isolation of [Ir(NO,)(CO)(PPh,),] and the novel [Ir(CO)(PPh,)2(N0,),Ag]. The former complex reacts readily with molecules XY to yield [Ir(N03)(CO)(PPh,),XY] (XU = O,, SO,, HgCI,, C1, etc.). Exactly the same products were obtained starting with [Ir(CO)(PPh,),(NO,),Ag], suggesting dissociation in polar solvents:219

Mossbauer spectroscopy has been applied to the problem of establishing the oxidation state of Ir in the adducts [IrCI(CO)(PPh,),XY] (XU = O,, H,, HC1, 2'6 *I7

218

219

B. L. Shaw and R. E. Stainbank, J . C. S. Dalton, 1972, 223. J. S. Bradley, D. E. Connor, D. Dolphin, J. A. Labinger, and J. A. Osborn, J . Amer. Chem. SOC.,

1972,94,4043. D. Forster, Inorg. Chem., 1972, 11, 473. D. N. Cash and R. 0. Harris, Cunad. J . Chern., 1971,49, 3821.

The Noble Metals

393

MeI, I,, or Cl,). Except for the oxygen adduct, the X-Y bonds have been broken in all these complexes. The data suggest a loss of electron density on Ir along the series from XY = H, to Cl,, which is consistent with the relative powers of H and C1 as a-donors.220 Comparison of the 31Pn.m.r. spectra of trans-[IrCl(CO)(PBu\R),] (R = Me, Et, or Pr) at room temperature and -60°C has shown that they exist as rotational conformers. The calculated energy barrier to rotation about the Ir-P bond of several kcal mol-' clearly indicates the significant steric effect of these bulky phosphine l i g a n d ~ . 'A~ ~more general investigation of the 31P n.m.r. spectra of phosphine complexes, including trans-[IrCl(CO)L,], has revealed a good correlation between the chemical shift of the free phosphine and the change in chemical shift on ~o-ordination.,~ [IrCl(CO)(PPh,),] has been reported to act as a homogeneous catalyst for hydrogen-deuterium exchange between D, and molecules such as acetic acid, methanol, ethanol, and m ~ r p h o l i n e . ~ ~ More interestingly, a number of phosphine compounds, including [IrCl(CO)(PPh,),], have been found to be homogeneous catalysts for the combination: H,

+ to2

-+

H,O

in toluene under ambient conditions.221 Although catalysis of this reaction by metal surfaces is known, homogeneous catalysis was previously unknown except by Cu+ ions at high temperatures and pressure. The electrical conductivity of the mixed valence complex Ir(CO)2.9Cll.l has been measured along the axis of the Ir chains. Tests indicated that small amounts of water can dramatically increase the conductivity, which may explain the considerable scatter often observed in such experiments. Temperature-dependent studies suggested semiconducting rather than metallic behaviour.222 Group VI Donors. Oxygen and sulphur donor ligands. In order to establish the bond character of co-ordinated oxygen more clearly, a I7O n.m.r. study has been carried out on the complexes [Ir(170,)X(CO)(PR,),] (X = C1 or I, R = Ph; X = C1, R = C7H7). Unfortunately, no resonance attributable to 1 7 0 2 could be found, suggesting that Vaska type compounds tumble at a rate which broadens the resonance beyond d e t e ~ t i 0 n . lOther ~~ workers have measured the first ionization energies of a range of P-diketonato-complexes of the type (32) [R', R 2 = Me, CF,, Ph, and mixtures; M = Ir(CO)2]. Ionization was postulated to occur from a molecular orbital with a significant participation of the Ir atomic 0rbita1.l~~ An X-ray analysis of [Ir(S,)(Ph,PC,H4PPh,),1C1,MeCN has appeared (see Table 4),showing it to be trigonal-bipyramidal and almost isostructural with the analogous oxygen complex.223 The sulphinato-complex [Ir(CO)(PPh,),(O,S-p-tolyl)] has been prepared

220

221 222

223

H. H. Wickman and W. E. Silverthorn, Znorg. Chem., 1971, 10, 2333. L. Vaska and M. E. Tadros, J . Amer. Chem. SOC.,1971,93,7099. F. N. Lecrone, M. J. Minot, and J. H. Perlstein, Inorg. Nuclear Chem. Letters, 1972, 8, 173. W. D. Bonds and J. A. Ibers, J . Amer. Chem. SOC.,1972,94,3413.


394

via the reaction of sodium toluene-p-sulphinate on [Ir(CO)(PPh,),(MeCN)]. The position of the v(S-0) frequency (1085 cm-') requires an 0-bonded sulphinate. It is interesting that ligand isomerization from 0- to S-bonding occurs when the [Ir(CO)(PPh,),(O,S-p-tolyl)] reacts with the ligands CO or oxygen : 2 2 4 PPh3 0 \ II CO-1r-O-S-R 'PPh,

+

L

oc\,

PPh, 0

,II

Ir-S-R

All,

8

A new type of sulphur dioxide complex of the type [Ir(SO,)(CO)(PPh,),(I-SO,)] has been reported from the treatment of [Ir(CO)(PPh,),I] with SO,. Co-ordination of the SO, to I is confirmed from the i.r. spectrum, and by analogy with the similar [Pt(PPh,), Me1 -SO,] for which an X-ray analysis has been performed (see Table 8). This report provides a warning that SO, may attach to sites other than the metal in metal complexes.225

Group I/ Donors. Nitrogen donor ligands. Dicyanoketiminato-complexes of the type [M(C,N,)(CO)(APh,),] (M = Rh or Ir; A = P or As) have been prepared via the metathetical reaction between K(C,N3) and trans-[MCl(CO)(APh,),]. The i.r. spectra of these compounds support N-bonding of the ligand (33).ls6 Treatment of the newly described [IrH(P(OPh),),] with NO has yielded the nitrosyl complex [Ir(NO){P(OPh)3)3].2" Nitrogen 1s binding energies have been determined by X-ray p.e. spectroscopy for [Ir(N0)2(PPh3),]PF6, [Ir(NO)(PPh,),I, [Ir(NO)(CO)(PPh,),], and several other metal nitrosyl complexes. Among the several interesting conclusions arising from this study were: (i) bent NO groups have low binding energies: (ii) there is a rough correlation between v(N0) and binding energies for linear NO groups; (iii) terminal and bridging NO groups apparently have the same electron densities since they are indistinguishable by this method.60 Phosphorus donor ligands. A wide range of Ir' and Ir"' complexes of vinylenebis(dipheny1phosphine) Ph,PCH=CHPPh,, have been prepared starting from Vaska's compound (Scheme 15). These complexes are similar in geometry and behaviour to their 1,2-bis(diphenylphosphino)ethaneanalogues, but are somewhat more stable., 26 The above four-co-ordinate complex [IrL2Ix has been independently prepared by other workers. A kinetic study of the oxidative addition of XY (O,, H,, HC1, CO, SO,) to this complex and its Co and Rh analogues has led to the unexpected reactivity order Co > Ir > Rh. This study provides the first direct comparison of the reactivities of planar d8 complexes of all three metals in a triad.ls8A convenient synthesis has also been described3' for the related diphenylphosphine complex [Ir(CO)(HPPh,),]+, 224

225

226

C. A. Reed and W. R . Roper, Chem. Comm., 1971, 1556. M. R . Snow, J. McDonald, F. Basolo, and J. A. Ibers, J . Amer. Chem. Soc., 1972, 94,2526. S. Doronzo and V. D. Bianco, Inorg. Chem., 1972, 11,466.

The Noble Metals

395

I

KX

[IrH,L,] X

HY--

/

[IrHXLJX

[IrL,]X

0

[Ir(O,)L,]X

Scheme 15

and for the bulky [Ir(C0)3(PB~'R,),]BPh, (R = Me, Et, Pr, or As part of an extensive synthetic study of trialkyl phosphite metal complexes, the cations [Ir{P(OMe),},]' and [Ir(P(OEt)3}5JChave been isolated as their tetraphenylborate salts from reaction of the phosphite with methanolic solutions of labile olefin or phosphine Ir complexes.82 The unusual complexes [Ir(CO),(PPh,)HgR] (R = p-tolyl, Ph, or PhCH,) and [Ir(CO),(PPh,)],Hg, containing Ir-Hg bonds, have been reported from the oxidative addition of RHgCl to suitable Ir-' substrates. 'H N.m.r. and i.r. data are consistent with the structure (34;M = Ir).',' Addition of NaBH,CN to rrans-[Ir(OC103)(CO)L,] [L = PPh, or P(C,H,,),] has yielded the first reported examples of a cyanohydroborato complex, trans-[Ir(BH,CN)(CO)L,]; its i.r. spectrum suggests that the BH,(CN)- ligand is N-bonded to Ir. Similar complexes, [Ir(BH,)(CO)L2], were obtained using BH,, but here spectral data indicate co-ordination through a double H bridge, Ir--H2 -BH,. One is tempted to suggest that such metal-hydroborato complexes are intermediates in the well-known synthesis of metal hydrides via reduction with BHJ or BH,(CN)-.161 Group IV Donors. New isocyanide complexes of the type [Ir(CNBu'),]Cl, [Ir(PPh,),(CNR),]Cl (R = But or p-ClC,H,), and [Ir(PPh,),(CNR),]Cl (R = But, Pr', p-ClC,H,, or p-MeC,H,) have been isolated from the reaction between free isocyanide and a variety of Ir substrates. Studies of the oxidative addition reaction: [Ir(CNR),]PF,

+ XY

-+

[Ir(CNR),XY]PF,

(XU = Br,, I,, BrCN, MeI, C,H,I, MeCOCl, CH,CH=CH,Cl,

HgCl,, SnCl,, SnPh,Cl) show that the product is trans. Addition to the other new complexes was also r e ~ 0 r t e d . A l ~general ~ route to the complexes [IrL(PF,),] [L = SiPh,, Si(OEt),, SiCl,, or GePh,] has been described, involving the addition of LH to the new compound 1r2(PF3)*(see above). Also reported are the complexes [Ir(SnPh,)(PF,),] and [Ir(PbPh,)(PF,),].' 2 9

396


Iridium(Irr).-Group VII Donors. Halogeno-carbonyl and -phosphine complexes. Treatment of chloroiridous acid with a two-fold excess of PBuiPr in propan-2-01 has yielded the dimer (PBu\PrH)[Ir,Cl,(PBu',Pr),]. On the other hand, the use of primary alcohols as solvents generally results in carbonyl abstraction from ROH, giving trans-[IrCl(CO)(PBu'Pr,),] as one of the products.227A preliminary communication has appeared.228An interesting observation has been the photoisomerization of the complexes mer-[IrX,L,] and mer-[IrX,(CO)L,] (X = C1, Br, or I; L = tertiary phosphine) to give theirfac-isomers in high yield. Furthermore, the addition of excess CNO-, SCN-, or N; to the reaction mixtures has yielded the new fac-[IrY,(PEt,),]. Several other new complexes are reported together with the properties of these fuc isomers.229 A large number of new complexes of the type [IrCl,X(PMe,Ph)(Ph,PC,H,PPh,)] and [IrCl,( AMe, Ph)(Ph,AC, H,APh,)] have been synthesized, and their ,*P n.m.r. spectra studied to determine the influence of the metal and the other ligands on the ,J(PMP) value.,,' Similar ,*P n.m.r. studies of a series of nier-[IrCl,L,] (L = tertiary phosphine) compounds have revealed a linear correlation between 31Pchemical shifts of the free phosphines and the change in chemical shift on co-ordination. The effect of changing the halide on the chemical shift was also Hydrido-carbonyl and -phosphine complexes. A series of hydride complexes [IrHCl(PPh,),(RCOO)] (R = Me. Et. Pr, H. Ph. CF,. MeCHCl, or p-NO,C,H4) (44)have been prepared uia the protonation of [Ir(N,)Cl(PPh,),] with

PPh

(44)

the appropriate carboxylic acid. The very high v(1r-H) frequencies (2221-2304 cm- ') suggest a low trans-labilizing influence for RCOO. These complexes undergo an interesting carbonylation reaction with CO : 2 3 '

PPhj

Similar studies of the protonation of [IrH(CO)(PPh,),] with CF,CO,H have 227

228 229

230 231

C. Masters, B. L. Shaw, and R. E. Stainbank, J.C.S. Dalton, 1972, 664. C. Masters, B. L. Shaw, and R. E. Stainbank, Chem. Comrn., 1971, 209. R. R. Brookes, C. Masters, and B. L. Shaw, J . Chem. SOC.( A ) , 1971, 3756. B. E. Mann, C . Masters, and B. L. Shaw, J.C.S. Dalton, 1972, 48. S. A. Smith, D. M. Blake, and M. Kubota, Znorg. Chem., 1972, 11, 660.

The Noble Metals

397

given the white complex [IrH,(CO)(PPh,)3][(CF3C02)2H], which contains dimeric trifluoroacetate as the anion.' 7 3 Reaction of chloroiridous acid with bulky PBu',R phosphines has produced the complexes [IrHCI,(PBu',R),], [IrHCl,(CO)( PBuiR),] (R = Me, Et, or Pr), or [Ir,HCl,(PBu',Me),]depending on the phosphine and/or solvent employed. Their 'H and 'P n.m.r. are reported.227An interesting observation has been the high-yield photoisomerization of the complexes mer-[IrHX,(PR,),] (X = C1, Br. or I) to their fuc-isomers by visible light.,,' The related [IrH,Cl(PPh,),] and [IrH,( PPh,),] complexes have been found to be homogeneous catalysts for H-D exchange between D, and molecules such as acetic acid. methanol. ethanol, and morph01ine.~~ Group VI Donors. Oxygen and sulphur donor ligands. Oxidative addition of tetrachloro-1,2-benzoquinoneto trans-[Ir(CO)C1(PR3),1 (R3 = Ph, or Ph,Me) has been shown to give the Ir" products [Ir(0,C,Cl,)(CO)Cl(PR3)2], whose structures (45) were confirmed from far-i.r. and 'H n.m.r. data. Comparison

with structure (38) for the Rh products shows that the addition takes a different geometric course depending on the metal. Observations with a series of other quinones indicated, not unexpectedly, that the ease of addition depends on the oxidizing ability of the q ~ i n o n e . ' * ~ Following a preliminary communication,' 86a a detailed report has appeared of the preparation of the sulphide complexes [IrX,L,] [X = C1, Br, or I : L = Me,S, Et,S, (CH,),S, or (CH,),S]. I.r., 'H n.m.r., and dipole moment studies indicate that they all have a common octahedral iner configuration.' 8 6 b The red thioacetamide complexes [IrCl,(MeCSNH,),] have been isolated from the reaction of Na,[IrCl,] with free ligand. Their i.r. spectra confirm that the ligand is unidentate and co-ordinates via the S atom.'g8 The synthesis of Ir(sacsac), (sacsac = dithioacetylacetonate) has been described in detail following an initial report.'" Comparison of its i.r. and 'H n.m.r. spectra with corresponding data for the analogous Ni", Pd", and Ptu complexes suggests that a depletion of the Tc-bonding electron density on the ligand backbone occurs on co-ordination to M"' rather than A re-investigation of the addition of H,L (46) to [IrCl(CO)(PPh,),] has shown that, as well as the product [IrHCl(HL)(CO)(PPh,),] previously a novel dithiolene complex of formula [Ir,L,(CO),(PPh,),] is 131

H. Singer and G. Wilkinson, J . Chem. SOC.( A ) , 1968,2516.

398

Inorganic Chemistry of the Transition Elements Me

SH

obtained. An X-ray analysis (see Table 4) showed it to have the novel structure (47).233 Five-co-ordinate S-bonded sulphinate complexes of the type [IrCl,(PPh,),(RSO,)] (R = Me, Et, Pr, C,H,, Ph. C6H,Cl, or C,H,N02) have been isolated

Me

from the reaction of RS0,CI with [Ir(N2)C1(PPh3)J. These compounds were found to undergo the facile rearrangement

which is the reverse of SO,-insertion into a M-alkyl

bond.234 Group V Donors. Nitrogen donor ligands. A series of complexes of the unusual 1,3-diphenyltriazenide ligand (9; R = Ph) has been reported, including [Ir(CO)(PPh,),L] and [IrH,( PPh,),L]. The i.r. spectra of these diamagnetic solids indicate bidentate co-ordination of L.62 Alcohols have been found to attack the co-ordinated NO group in the cations [IrCl,(NO)(APh,),] (A = P or As), yielding the alkyl nitrite complexes [IrCl,(RONO)(APh,),]. These interesting reactions are analogous to the well-known attack of R O - on cationic carbonyl complexes. The reaction is reversed by acid : H+

[IrC13(RONO)(APh3)2] 233 234

[IrCl,(NO)(APh,),]

G. P. Khare and R. Eisenberg, Inorg. Chem., 1972, 11, 1385. M . Kubota and B. M. Loemer, Inorg. Chem., 1972,11,469.

.+

The Noble Metals

399

Also described is the preparation of [ I ~ ( N O ) ( A S P ~ , ) A , ] .detailed ~ ~ ~ study of the acid decomposition of [Ir(NH,),N,]'+ suggests the initial formation of an unstable nitrene complex (48), [Ir(NH3)5NH]3+.The nitrene is a very strong nucleophile and undergoes the chemistry shown in Scheme 16. All the complexes except (48) were isolated.236.2 3 7 Comparison with the known chemistry of the indicates the important role of analogous Ru nitrene, [Ru(NH3),NHI3

+,,,'

[Ir(NH3)5N3] * +

1 H+

[Ir(NH3),NHI3++ N,

""1/ (48)

HCI

[Ir(NH3),(NH,C1)]3

+

Ln(NH3),WH,OSO,)l2

+

Scheme 16

the metal. The substitution of co-ordinated C1- in trans-[IrCl,(py),]Cl by nucleophiles such as I-, Br-, and NCS- does not appear to proceed thermally.239 The retardation compared to the corresponding ethylenediamine complexes240may be steric in origin. However. with U.V.irradiation, the complexes trans-[IrX,(py),]X (X = Br or I) are readily formed, together with [IrX,(py),] and [IrC1(NCS),(py),l .2 X-Ray powder pattern studies of the complexes [M(phen),X,]"+ and [M(bipy),YZ]"' [M = Co, Rh, Ir, or 0 s : X = C1, H,O, or +ox; YZ = C1, or (OH)(H,O)] show that each metal in each series is isomorphous. A cis configuration is therefore assigned to all complexes.' l S Luminescence quantum yields have been measured for a series of [IrCI,(N-N),CI complexes (N-N = phen or bipy, or diphenyl derivatives), permitting a quantitative estimate of the effect of ligand phenyl substituents." A normal-co-ordinate analysis (i.r. has been carried out for [Ir(NH,), C1]C1,.24 Phosphorus and arsenic ligands. Five-co-ordinate complexes [Ir( PPh,)(L'Lt)] of the 'tripod-like' ligand (49; L', L2 = P. As) have been obtained by refluxing L'L: with [IrHCI,(PPh,),] in benzene. Their 'H and 31Pn.m.r. spectra suggest a trigonal-bipyramid complex geometry. which is confirmed from an X-ray analysis of the L' = L2 = P member (see Table 4).242The oxidative addition C. A. Reed and W. R. Roper, J.C.S. Dalton, 1972, 1243. B. C. Lane, J. W. McDonald, V. G. Myers, F. Basolo, and R. G. Pearson, J . Amer. Chem. SOC., 1971,93,4934. B. C. Lane, J. W. McDonald, F. Basolo, and R. G. Pearson, J . Amer. Chem. SOC., 1972,94,3786. L. A. P. Kane-Maguire, P. S. Sheridan, F. Basolo, and R. G. Pearson, J. Amer. Chem. SOC.,1970, 92, 5865. I. B. Baranovskii, Russ. J. Inorg. Chem., 1971, 16, 620. R. A. Bauer and F. Basolo, Znorg. Chem., 1969,8, 2231. Y. Y. Kharitonov, N. A. Knyazeva, G. Y. Mazo, I. B. Baranovskii, and N. B. Generalova, Russ. J . Inorg. Chem., 1971, 16, 1172. L. M. Venanzi, R.Spagna, and L. Zambonelli, Chem. Cornm., 1971, 1570.

lJ5 236

237 238

239

240 241

242


400

Ph,L2

of [P(Y)F2C1) or [P(Y)F,Br) (Y = 0 or S ) to [Ir(CO)X(PPh,),] has yielded phosphorodifluoride complexes of structure (50).243 Other new complexes reported are the phosphites [IrHX2{P(OAr),} 3]

(X = C1, Br, or I; Ar = aryl), which were shown to undergo intramolecular ligand-metal H transfer and elimination reactions2 l 2 Group IV Donors. The complexes [IrH2(CO)(R,M)(PPh,),1 (R,M = Cl,Si, Cl,Ge, or Me,Si), some of which are new. have been prepared c i t i the action of R,MH on tr~ns-[IrCl(CO)(PPh,)~]. These dihydrides were found to undergo ready exchange with silanes and stannates: the proposed mechanism is shown in Scheme 17.244 H Ph3P\ I ,MR,

Ph,P / f r l H

co

A stereochemical investigation of the ‘carbonyl insertion’ reaction of 243 244

C . B. Colburn, W. E. Hill, and D. W. A. Sharp, Inorg. Nuclear Chern. Letters, 1972, 8, 625. F. Glockling and J. G. Irwin, Inorg. Chim. Acfa, 1972, 6, 355.

The Noble Metals

40 1

AsMePh, or AsMe,Ph (L2) with [IrCl,Et(CO),L'] to yield [IrCl,(COEt)(CO)L'L2] (L' = AsMePh, or AsMe,Ph) has suggested the mechanism set out in Scheme 18. The symmetrical rate-determining step would be better labelled as concerted rather than as either CO insertion or alkyl migration.245

co EtOC L"

'Ir

I C1 I --L2

'

c1

Scheme 18

Iridium(1v). -Group VZI Donors. All reported studies of IrN concerned halogen complexes. Pure IrF, has been prepared for the first time via reduction of IrF, on a hot filament of Ir or W. X-Ray powder pattern studies of this volatile, red-brown compound showed it to be different from IrF, or IrF5.246 A simple melt synthesis of K,IrF, has been developed involving the reaction : K,[IrCl,]

+ 6KHF,-&-

K,[IrF,]

+ 6KF + HCl

This method has the advantage of not requiring fluorine or other corrosive reagents.' I 6 Equilibrium constants have been measured for the interconversion of the species [IrC1, (OH)] - , [IrCl,( 0H),] -, [IrCl (OH),] - . and [I rC1 (0H),]' in aqueous solution at pH 2.5-6.5.247 The diffuse reflectance spectrum of [IrF,]'has been recorded between 4 and 50 cm-', permitting calculation of the crystal-field parameters D, and B, and the spin-orbit coupling constant. Similar studies of [IrX,I2- (X = C1, Br, or I) also revealed bands due to transitions between spin-orbit split components of the T2gground state. The extent of covalency was shown to increase in the order F < C1 < Br < 1."- Raman and i.r. studies have also been employed to compare covalency among hexahalogen complexes. Force-constant calculations for [IrX,]'- (X = C1. Br. or I) and [IrX,I3- (X = C1 or Br) indicate that covalency increases with increasing formal charge on the Ir.248

,

'

,

,

245

246 247 248

2c

R. W. Glyde and R. J. Mawby, Inorg. Chim. Acta, 1971,5, 317. W. A. Sunder and W. E. Falconer, Znorg. Nuclear Chem. Letters, 1972, 8, 537. V. E. Kalinina, L. V. Shvedova, and K. B. Yatsimirskii, Russ. J . Znorg. Chem., 1971, 16, 728. G. L. Bottger and A. E. Salwin, Spectrochim. Acta, 1972, =A, 925.


402

Table 4 X-Ray data f o r iridium compounds Compound IrF, [Ir(O2)(CO)CI(PPh2Et),1

,

R -

0.050

[Ir(S,)( Ph PC, H,PPh ,),]CI,MeCN

0.050

[Ir(PPh3)L]BPh,

0.084

0.06 1

Comments Ref: Powder pattern only. a General features similar to h [Ir(O,)(CO)X(PPh,)z]. 0-0 distance = 1.461 A. Approximate t rigonal C bipyramid structure. Nearly isostructural with analogous oxygen carrier. S, is Tc-bonded at an equatorial site. Ligand tris(a-diphenyld phosphinopheny1)phosphine is quadridentate. Co-ordination about Ir is trigonal bipyramid.

Octahedral co-ordination about each Ir. Two Ir atoms bridged by S atoms of two tdt lipands as shown below.

e

Qsq Me

Me

S

S

\I/

Ir

\k P Ir

Me (a)W .A. Sunder and W. E. Falconer, Inorg. Nuclear Chem. Letters, 1972,8, 531; (b)M. S. Weininger, I. F. Taylor, and E. L. Amma, Chem. Comm.,1971, 1172; (c) ref. 223; (d)L. M. Venanzi, R. Spagna, and L. Zambonelli, Chem. Comm., 1971, 1570: (e) G. P. Khare and R. Eisenberg, Inorg. Chem., 1972, 11, 1385.

A short communication reports the oxidation of [BPh,]aqueous solution, according to the equation: BPh,

+ 2IrCIi- + H,O

+

Ph,BOH

by [IrCl,]’-

+ Ph, + 2IrCI:- + H +

in

The Noble Metals

403

Iridium(v).-Bo th crystal-field and charge-transfer bands have been observed in the diffuse reflectance spectrum of [IrF6]-. Calculation of the spin-orbit coupling constant and crystal-field parameters indicated that the degree of covalency is high for a fluoro-complex, and comparable with that found for quadrivalent [MF6I2- species of the first transition series.12 5 Palladium Palladium(O).---Interest in this oxidation state is increasing. Full details have appeared of the preparation of the complexes [Pd(CO)(PPh,),], [Pd,(CO),(PPh,),], and [Pd3(CO),(PPh3),], following an earlier c o m r n u n i ~ a t i o n . ~ ~ ~ The oxidative addition reactions of these complexes are also described, e.8.:2 5 0 [Pd(CO)(PPh,),]

+ Me1

+

[PdI(COMe)(PPh,),]

A convenient route has been found to [Pd(PPh,),] and Pd[P(OPh),],, which were previously only accessible with difficulty. The method involves the treatment of [Pd(n-Me-allyl)Cl], with the appropriate ligand in CH,Cl,. Molecular weight determinations in benzene (under argon) indicate that these complexes, like their Pt analogues, are only slightly dissociated in solution.25' A re-investigation of the complexes previously formulated as [Pd(HPPh,),(PPh,),]' 5 2 indicates that they are in fact tetrahedral Pdo complexes, [Pd(HPPh,),], Main support for this conclusion comes from 'H n.m.r. data in the presence of excess PPh, or Ph,PC,H,PPh,, which is consistent with the release of four molecules of diphenylphosphine per Pd atom.253

I

H

A quinazoline-2.4-dithione complex [Pd(LH),(PPh,)] has been isolated from the reaction of the free ligand LH (51) with [Pd(PPh,),]. Unidentate co-ordination of the ligand via a sulphur atom was confirmed from the i.r. spectrum. Oxidative addition with iodine is r e p ~ r t e d54. ~ 249

251 252

253

254

A. Misono, Y. Uchida, M. Hidai, and K. Kudo, J . Organometallic Chem., 1969, 20, 7. K. Kudo, M. Hidai, and Y. Uchida, J . Organometallic Chem., 1971,33, 393. W. Kuran and A. Musco, J . Organometallic Chem.. 1972,40, C41. K. Issleib and E. Wenschuc, 2. anorg. Chem., 1960, 305, 15. C. W. Weston, G. W. Bailey, J. H. Nelson, and H. B. Jonassen, J . Znorg. Nuclear Chem., 1972, 34, 25 1. U. Agarwala and L. Agarwala, J . Znorg. Nuclear Chem., 1972, 34, 251.


404

An l 8 0 isotopic i.r. spectral study has been carried out for [Pd(O,)(Bu'NC),], and several other t ransition-metal-oxygen complexes. Definite assignments of the M-0 vibrations were made for the first time, and the M--0 stretching force constants were correlated with the reactivities of the oxygen ligand. The oxygen co-ordination in the p!ladium showed some deviation from the side-on isosceles structure (3).'"9 The same authors have made a systematic study of the reactions of [Pd(O,)(Bu'NC),]. suggesting four different types of behaviour: (i) atom-transfer redox: (ii) atom-transfer oxidation: (iii) oxidative substitution: and (iv) metal-assisted peroxidation reactions. 0-0 bond cleavage occurs in (i) and (ii), examples of which are. r e s p e c t i ~ e l y , ~ ~ ' [Pd(O,)(RNC),]

+ excess RNC -Pd(RNC),

+ 2RNCO

Other new complexes reported are the species [PdL(Bu'NC),], where L is a large variety of unsaturated ligands e.g. azobenzene. All were prepared in a similar manner to the known oxygen complex.256 [Pd(PPh,),] has been foupd2'- to be an effective agent for the dealkylation of alkyl azides: [Pd(PPh,),]

+ RN,

+

[Pd(PPh,),(N,),J (R

=

Me or Et)

This is not surprising in view of the similar behaviour known for [Pt(PPh,),] with aryl and acyl azides.2s8 1.r. spectral evidence has been reported for the formation of Pd(CO), when Pd atoms are co-condensed with a large excess of argon-CO mixtures at 27 K.2s9 Palladium(~).-Apart from the unusual sandwich compound [PdAI,Cl,(C6H6)]2.2h0 no complexes of Pd' are known. However. the new series [PdX(Bu'NC),], ( X = C1. Br. or I) has now been prepared cia the reaction:

-

[P~X,(BU'NC)~] + Pd(Bu'NC)2

PhCl

LPdX(Bu"C)J2

Stabilization of the Pd' oxidation state is apparently due to the alkyl isocyanide ligands. since attempts to prepare similar phosphine complexes were unsuccessful. The i.r. spectra of these air-stable. yellow compounds indicate the presence of bridging halides, which are surprisingly resistant to attack by reagents such as phosphines. 'Their diamagnetism suggests strong magnetic interchange between the two i19 nuclei. possibly r i a bridging halides.26 255 256

257

"*

259 260

26i

S. Otsuka, A. Nakamura, Y. Tatsuno, and M. Miki, J . Amer. Chem. Soc., r972,94, 3761. S. Otsuka, T. Yoshida, and Y . Tatsuno, J . Amer. Chem. SOC.,1971,93, 6462. B. Hessett, J. H. Morris, and P. G. Perkins, Znorg. Nuclear Chem. Letters, 1971, 7 , 1149. W. Beck, M. Bauder, G . La Monnica, S. Cenini, and R. Ugo, J . Chem. SOC.( A ) , 1971, 113. J. H. Darling and J. S. Ogden, Inorg. Chem., 1972, 11, 666. G. Allegra, G. T. Cassagrande, A. Immirzi, L. Porri, and G. Vitulli, J . Amer. Chem. SOC.,1970, 92, 289. S . Otsuka, Y Tatsuno, and K. Ataka, J . Amer. Chem. SOC.,1971,93,6705.

The Noble Metals

405

Palladium(I1). -Group VII Donors. Halide donor ligands. An X-ray photoelectron spectroscopy study has recorded the 3dg and 3ds binding energies of the Pd in a range of complexes, including PdX, (X = C1, Br, or I) and K,[PdX,] (X = C1 or Br). The energies were related to electronegativity differences between the Pd and the ligand donor atoms. Bridging bromides (e.g. PdBr,) could be distinguished from the terminally bonded Br in K,[PdBr4].262 Molecular orbital calculations have permitted the prediction of the lineshape of the magnetic c.d. of [PdCl,]'-. Agreement with experiment allows assignment of the electronic transitions in this complex.263 The separation of [PdC1,I2- from the ions [AuCl,]-. [PdC1,I2-, and [PtCl,]'has been reported using reversed-phase chromatography on paper treated with triallyl phosphate.264 Halogeno-carbonyl and -phosphine complexes. The action of CO on the chlorobridged complexes [PdCl,], and [PdLCl,], has been shown to give the species [Pd(CO)CI,], and [Pd(CO)LCl,] [L = DMSO, Et,S, or (C,H,S)], respectively. The new [Pd(CO)LCl,] complexes are air-sensitive and readily hydrolysed, and contain only terminal CO groups (i.r.).26sHigh-yield syntheses of the new [PdX,(PR,),](BF,), (X = CI, Br, or I; R = Ph or Et) have been reported uia the treatment of trans-[PdX,(PR,),] with AgBF, in acetone. Their reactions with pyridine and PPh, were studied, yielding further novel complexes cis[PdC1(PEt3),py]BF4 and [PdCl(PPh,),], respectively.266 The related bulky phosphine complexes [PdX,(PBu'R,),], [PdX,(PBu\R),]. and [Pd,X4(PBuiPh),] (X = C1, Br, or I: R = Me, Et, Pr, Bun. Ph, or p-tolyl) have also been prepared.267A 31P n .m.r. study of these and similar complexes37 has revealed a linear correlation between the chemical shift of the free phosphine and the change in chemical shift on co-ordination. cis or trans disposition of the phosphine ligands was established by the 'H n.m.r. pattern of the t-butyl p h ~ s p h i n e . ~The ~ ' unusual, temperature-dependent asymmetry of the lowest energy ligand-field band of the trigonal-bipyramidal complexes [PdX(L'LQ)]+ [X = C1, Br, I, or CN; L'L: = (Me,AsC,H,),L' (L' = P or As), or (O-MeLC,H,),P (L = S or Se), or (o-Ph,LC,H,),L' (L' = L = P or As)] has been explained in terms of permanent ground-state distortion.268 Group V I Donors. Oxygen and mixed oxygen-nitrogen donor ligands. A more convenient synthesis has been reported for the chiral complex [Pd(tfacCam),] (52), involving the reaction of Ba(tfacCam), with PdC12.146 Detailed conformation studies have been made on the complexes [PdX(AMe,Ph)(O,CR),] (X = C1, Br, or I; A = P or As; R = Me, CH,Cl. CH,Br, 262

G. Kumar, J. R. Blackburn, R. G. Albridge, W. E. Moddeman, and M. M. Jones, Inorg. Chem.,

263

H. Kato, Bull. Chem. SOC.Japan, 1972, 45, 1281. C. Liteanu and A. Ungareanu, Rev. Roumaine Chem., 1971,16, 1769. E. A. Andronov, Y. N. Kukushkin, and V. G. Churakov, Russ. J . Inorg. Chem., 1971, 16, 1235. K. R. Dixon and D . J. Hawke, Canad. J. Chem., 1971,49, 3252. B. E. Mann, B. L. Shaw, and R. M. Slade, J . Chem. SOC.( A ) , 1971,2976. J. W. Dawson, H. B. Gray, J. E. Hix, J. R. Preer, and L. M. Venanzi, J. Amer. Chem. SOC.,

1972, 11, 296. 264 265

366 267 268

1972,94,2979.

406


CCI,. CF,. CMe,. or CPh,). which were prepared by addition of Ag0,CR to the appropriate [PdX,(AMe,PH),]. Their i.r. spectra confirm the presence of bridging carboxylate groups. while their 'H n.m.r, suggest the structure (53: M = Pd). Variable-temperature 'H n.m.r. measurements showed confor-

X \ /

PhMezA

X

AMe2Ph

mational averaging at higher temperatures. The low E (3-6 kcal mol- ') and large negative A$( -20 to -40 e.u.) was interpreted in terms of an exchange bond to give a mono-pprocess involving rapid solvolysis of a Pd-0,CR 02CR intermediate. rather than a simple inversion of the Pd,C204 ring.268a Charge-transfer complexes of [Pd(8-quinolinolato),] with several halogensubstituted p-benzoquinones have been isolated of the type [Pd(S-quinolinolato)J,L. Bands due to these charge-transfer interactions were a'ssigned from the diffuse reflectance spectra.269The grey complex [PdL2],2H,O (L = 8-amino-7-hydroxy-4-methylcoumarin) has been prepared from the reaction of free ligand with PdCI, at pH 3. 1.r. studies of the diamagnetic complex confirmed co-ordination through both 0 and N.39A subsequent spectroscopic study of a series of metal complexes of this ligand, including the above [PdL,],2 H 2 0 suggests a correlation between certain vibrational bands, e.g. vaBym(NH2), v(M-N), and the stability of the corn pound^.^^ cis- and trans-isomers of the a-amino-acid amidato-complexes [PdL,] (L = L-valine, L-phenylalanine, or L-proline ions) have been isolated and 268a

268b 269

J. Powell and T. Jack, Inurg. Chem., 1972,11, 1039. D. M.Barlex and R. D. W.Kemmitt, J.C.S. Dolton, 1972, 1436. Y.Iida, Bull. Chem. SUC.Japan, 1971,44, 2564.

The Noble Metals

407

separated from the action of free LH on Li,PdCI,. Their u.v.-visible and c.d. spectra were recorded.270C.d. studies, together with 'H n.m.r. data. have been shown to be powerful tools in elucidating the changes occurring in tripeptide complexes such as [Pd(Gly-gly-~-Ala)]- on the addition of excess base.271 Sulphur donor ligands. Ligand-exchange reactions have yielded a series of mixed dithiolene complexes of the type [Pd{S,C,(CN),}(S,CNR,}](R = Et, Bu, or Ph) and [Pd(S,C,(CN),}{S2CN(CN)}]2-. Voltammetric studies in CH2C12 revealed that the complexes could undergo a one-electron oxidation, _the half-wave potentials of which were intermediate between those of the unmixed complexes.272A range of alkylsulphoxide complexes of composition [PdL,](BF,), and [PdX,L,] (L = DMSO, DESO, C,H,SO, dipropylsulphoxide, or di-isoamylsulphoxide) have been prepared via direct reaction between L and [Pd(MeCN),I2+ and PdCl,, respectively. 1.r. studies show that many of these contain both S- and 0-co-ordination sites. Particularly interesting is [Pd(IASO),](BF,),, which is the first example of a completely 0-bonded Pd" sulphoxide. Such behaviour is attributed to the steric effects of the large isoamyl The thio-oxinato-complex [Pd(C,H,NS),] (54;M = Pd) has been isolated. and its N and S co-ordination confirmed from i.r. data.274

A similar study reports the complex [PdL,]Cl, [L = 2-thiophenaldoxime (55)] in which the ligand is bonded to Pd uia S and N atoms.275Reaction of

quinazoline-2,4-dithione [LH ( 5l)] with PdCl, in acetone-butanol solvent has yielded the red-brown [PdL,]. 1.r. studies support bidentate co-ordination of the ligand through both N and S, donors.25" New 2-benzothiazolethiol 270

T. Komorita, J. Hidaka, and Y. Shimura, Bull. Chem. SOC.Japan, 1971, 44, 3353.

272

J. G . M. Van der Linden, J . Znorg. Nuclear Chem., 1972, 34, 1645. J. H. Price, A. M. Williamson, R. F. Schramm, and B. B. Wayland, Znorg. Chem., 1972, 11, 1280. Y. Mido and E. Sekido, Bull. Chem. SOC.Japan, 1971,44, 2130. M. P. Coakley and M. E. Casey, J . Znorg. Nuclear Chem., 1972, 34, 1937.

'" T. P. Pitner, E. W. Wilson, and R. B. Martin, Znorg. Chem., 1972, 11, 738. 273 274

275

408


[LH (56)] complexes have been prepared from [PdC1,J2 - employing Scheme 19 (M = Pd). 1.r. and ‘H n.m.r. studies indicate that the ligand is only bidentate (Sa and N bonded) in [ML,].276

The thioacetamide complex [Pd(MeCSNH,),]Cl, has been isolated from the reaction of K2PdCl, with free ligand. Its i.r. spectrum confirms that the ligand is unidentate and co-ordinates ria the S group.’” A similar conclusion was On the arrived at for [PdCl,L2].6H,0 (L = dimethylaminoethanethiol).’ other hand, the ligand thiovanol (CH2SHCHOHCH20H) forms the dia-

Scheme 19

magnetic [PdL,], whose u.v.-visible and i.r. spectra suggest a square-planar structure with bidentate ligands.’ 8 9 A related study describes the synthesis of the Schiff base complexes (57) and ( 5 8 ) (M = Pd: X = CI, Br, I. NCS. or ~ 0 4 . 2 7 7

Y

SMe

I c-s

‘ 1

NI

MX

NMe

II

CH

’ (57)

(58)

An interesting group of polymeric complexes. including (59: R = p-MeOC,H,), have been reported. These complexes readily expand their

276

W.

M.Shul’man and T. V. Zagorskaya, Russ. J . Inorg. Chem., 1971, 16, 720.

’’’ M. Akbar Ali, S. E. Livingstone, and D. J. Phillips, Inorg. Chim. Acta, 1971, 5,493.

The Noble Metals

409

co-ordination to form adducts with Lewis bases, a property which has made them useful for the chromatographic separation of various bases such as amines., 7 8 Other new complexes prepared are the diamagnetic [Pd(SSeCNR, j,]

(R = Me or Etj species, uia the action of Me,SnCl(SSeCNR,j on [PdCI,I2-. These orange-red complexes contain both Pd-S and Pd-Se Variable-temperature ‘H n.m.r. studies of the chelates [PdX,(RSC,H,SR)] (X = Cl, Br, or I; R = Me, Et, Pr, Pr’. or Bu) have been interpreted in terms of inversion at S between the meso and ($-)-isomeric forms (59a; M = Pd).

-

,CH2-CH S

‘Me

Me’

c1’

‘c1

The rate of inversion increased with increasing trans influence of X, and was A preliminary account more rapid than for the corresponding Pt has appeared., 7 9 b X-Ray analyses (see Table 5) of ‘the adducts Pd(S,PPh,),,PPh, and Pd(S2PPh,),,2PEt,, previously formulated280 as examples of five- and sixco-ordinated Pd”, have shown them to have four-co-ordinate structures (60) and (61), respectively.281

Another interesting X-ray study (see Table 5) has indicated that the dithiolene complex Pd(S,C,H,), has a dimeric structure (62: M = Pd) containing

”*

W. Kuchen, J. DeIventhaI, and H. Keck, Angew. Chem. Internal. Edn., 1972, 11,435. T. Tanaka and N. Sonoda, Inorg. Chem., 1971,10,2237. 279’ R. J. Cross, I. G. Dalgleish, G. J. Smith, and R. Wardle, J.C.S. Dalton, 1972, 992. 2’9bR. J. Cross, G. J. Smith, and R. Wardle, Znorg. Nuclear Chem. Letters, 1971, 7 , 191. T. A. Stephenson and B. D. Faithful, J . Chem. Soc. ( A ) , 1970, 1504. J. M. C. Alison, T. A. Stephenson, and R . 0. Gould, J . Chem. SOC.( A ) , 1971, 3690. 279

Inorganic Chemistry of the Transitiorl Elements

410

a very short Pd-Pd bond (2.79A). This novel arrangement is distinct from the laterally displaced dimeric structures exhibited by several other bis(dithiolene) complexes where interaction is via M-S bonds.282

Group I/ Donors. Nitrogen donor ligands. A series of complexes of the unusual 1,3-diaryltriazenido ligand (9) has been prepared, including [Pd(PPh,),L2] ( L = 1.3-di-p-tolyltriazenido). The i.r. spectrum of this diamagnetic solid indicates unidentate co-ordination of L.62 The metathetical reaction between K(C4N3) and [PdCl(Me,dien)]PF, has yielded the dicyanoketiminatocomplex [Pd(C,N,)(Me,dien)]PF,. A N-bonded structure (33: M = Pd) is ~ u g g e s t e d . ' ~Complexes ~ of substituted 1.2.3-benzotriazole (63: R = H. PhCH,, or CH,=CH) have been described, of the type [PdCl,L,]. The

I

R

presence of a strong v(N-H) band in their i.r. spectra confirms co-ordination through either N-2 or N-3.283An interesting preparative and spectral study of the complexes trans-[PdCl,(Me,Nj,] and (Pr,N)[PdCl,(NMe,)] has shown that NMe, generated a M eaker c r m s influence than the corresporiding phosphine and arsine, and lies below ammonia in the spectrochemical series.284 Other new complexes reported are the N-bonded morpholine complex [PdC12(C,H80N),].Z85 and a series of substituted propane-1.3-diamine (64) R

I

H2N-CH,-CH-CH,-NH, (64) R 282

285

C1 or OH

K . W. Browall, L. V . Interrante, and J. S. Kasper, J . Amer. Chem. SOC.,1971, 93, 6289. T. Mitsudo, M. Tanake, K. Yamamoto, and Y. Takegami, Bull. Chem. SOC. Japan, 1972,45, 925. P. L. Goggin, R. J. Goodfellow, and F. J. S. Reed, J.C.S. Dalton, 1972, 1298. R. A. Singh and E. B. Singh, J . Inorg. Nuclear Chem., 1972,34,769.

'" Y . Watanabe,

284

=

The Noble Metals

41 1

compounds of the type [PdL,X,] and [PdL2I2+ (X = C1 or Br). Several of the [PdL,X,] species exhibited polymorphism which was attributed to either different H-bonded linkages or different chelate ring conformations in the two forms.286In solution, their *Hn.m.r. spectra are consistent with a preference for a chair-type conformation with the C1 or OH A re-investigation of the complex [Pd(en)(enH)Cl]Cl,.H,O has confirmed this formulation containing a protonated ethylenediamine ligand. In addition, the complex was observed to undergo a facile solid-state reaction : [Pd(en)(enH)CI]CI,A [Pd(en)Cl,] + H2NCH2CH2NH ,C1 Similar studies with the bromo- and iodo-analogues showed the reactivity order I > C1 > Br.287Unlike corresponding Rh"' and Pt" complexes, K,[Pd(N02)4]does not react with NH,f salts to yield molecular nitrogen species. Instead, the compounds trans-[Pd(NH,),Cl,], from NH,C1, and trans[Pd(NH,),(NO,),], from (NH,),SO,, are produced.288Two related papers report the preparation and thermal decomposition studies of a range of substituted pyridine and pyrazine complexes of the type [PdX,L,] (X = C1, I. or NO,). Their decomposition behaviour was similar to that of [Pd(NH,),X,], yielding PdX, (X = C1 or I) as the final p r ~ d u c t . ~ * ~ * ~ ~ ' An X-ray p.e. spectroscopy study has recorded the Pd 3dZ and 3ds binding energies in a range of complexes, including [Pd(CN),], K,[Pd(CN),], [Pd(PPh,),(CN),], and K,[Pd(NO,),]. The energies were explained in terms of electronegativity differences between the Pd and ligand donor atoms, and 7t-bonding effects.262Polarographic examination of a series of [PdL,] complexes has revealed the following order of reducibility, L = C1 > Br > SCN,NO,, ox >a-pic, p-pic, MeNH,, e n > N H , >CN.," In contrast to its five-co-ordinate Ni" analogue,292an X-ray analysis of the newly prepared (65) shows it to have a distorted square-planar structure (see Table 6).293 Me

CH2-N-

/

Me

286

I

I

Me

T. G. Appleton and J. R. Hall, Znorg. Chem., 1972, 11, 112.

286"T. G. Appleton and J. R. Hall, Znorg. Ckem., 1972, 11, 117. 281 288 289 290 29 1

292 293

D. A. Johnson and W. H. Delphin, Inorg. Nuclear Chem. Letters, 1971, 7 , 717. V. M. Volkov and A. I. Korosteleva, Russ. J . Znorg. Chem., 1971, 16, 1384. J. E. House and R. Farran, J . Inorg. Nuclear Chem., 1972, 34, 1466. R. Farran and J. E. House, J . Inorg. Nuclear Ckem., 1972,34, 2219. M. Hirota, Y. Umegawa, M.' Nakamura, and S. Frejewara, J . Znorg. Nuclear Chem., 1972, 34, 2617. J. Rodgers and R. A. Jacobsen, J . Chem. SOC.( A ) , 1969,2036. M. G. B. Drew, M. J. Riedl, and J. Rodgers, J.C.S. Chern. Comm., 1972,234.

412


A further interesting X-ray structural study has been that of (AsPh,),[Pd2(N3)6](66). This reveals similar asymmetry in the two N-N bond lengths for the bridging (1.239 and 1.142 A) and terminal (1.205 and 1.139 A) azide groups. Such structural equivalence indicates that there is no appreciable change in electronic character when a terminal azide co-ordinates to a second Pd via a normally unshared electron pair on the trigonal N atom (see Table 6).294 N

I

N

N

I

N

Phosphorus and arsenic donor ligands. A general synthesis has been reported for a wide range of cationic phosphite complexes of the noble metals, including [PdL4I2+, [PdL,]’+, and [PdXL,]’, where L = P(OMe), and/or P(OEt),, X = C1 or Br. The Pd complexes readily dissociate in solution.82 Reaction of the little-studied ligand diphenylphosphine oxide with K2[PdX,] (X = Cl or Br) has produced the complexes [PdX(PPh,O)(PPh,OH),], [Pd[Pd,X,(PPh20)2(PPh,0H)2], and [PdX(PPh,O)(PPh,OH)(PPh,O),], (PEt,)]. 1.r. studies show that the last two complexes have a cis arrangement of one PPh,O and one P P h 2 0 H , giving a symmetrical H-bonded system (67; M = Pd).295

Complexes of the type [PdX,L] (X = C1, Br. I, or SCN) and PdL,Y, (Y = CI, Br, I, SCN, or C10,) have been prepared with the hybrid ligands (68)--170). 1.r. data confirm that the [PdX,L] compounds are square-planar with bidentate L. However. depending on the nature of Y, the PdL,Y, species exhibit a variety of four-, five-. and six-co-ordinate forms containing both bidentate and unidentate (As bonded) hybrid ligand~.,’~ 294

295 296

W. P. Fehlhammer and L. F. Dahl, J . Amer. Chem. SOC.,1972,94, 3377. K . R. Dixon and A. D . Rattray, Cunad. J . Chem., 1971,49, 3997. B. Chiswell, R. A. Plowman, and K. Verrall, Inorg. Chim. Acta, 1972, 6, 275.

413

The Noble Metals

Similar, but more extensive, studies of the co-ordination behaviour of the bifunctional ligands (70a) and (70b) with a range of metals have revealed both P,N and P,P bonding. For the Pd" complexes [PdX2L] (X = C1, Br, or I), i.r. data indicate that both ligands employ P,P co-ordination. The choice of donor atom is discussed in terms of chelate ring size and stereochemical preferences of the various metals.269a

'CH,PPh

'PPh, (70b)

(70a)

Complexes of the type [PdX,L]X (X = C1, Br, I, CNS, or CN; L = Et2PC2H4PEt,) have been prepared as part of a survey to determine the factors favouring five-co-ordination. Unlike some similar Ni" complexes, these were four-co-ordinate square-planar. The thiocyanate complex was shown (i.r.) to contain both N- and S-bonded CNS.296b Both mono- and di-nuclear arsine complexes of formula [PdX,(AsR,),] and [Pd,X,(AsR,),] (R = Ph or p-tolyl; X = C1, Br, or I) have been obtained by treating PdX, with free arsine. Bridge splitting reactions of the dinuclear complexes with nucleophiles are also reported, giving [PdX2L'L2] (L2 = PR,, AsR,, primary amine~).,'~A study of the co-ordination behaviour of the

Me As

269a

W. V. Dahlhoff, T. R. Dick, G. H. Ford, W. S. J. Kelly, and S. M. Nelson, J. Chem. Soc. ( A ) ,

296b

E. C. Alyea and D. W. Meek, Inorg. Chem., 1972, 11, 1029. D. Negoiu and V. Serban, Rev. Roumaine Chim., 1971, 16, 1347.

1971, 3495. 297


414

potentially terdentate ligand (71) with [PdX4I2- has shown that, in fact, only two As donor atoms bond to the metal, yielding [PdLX,] (X = Cl, Br, or I), and [PdL,] (c104),.298 The extended series [PdX,(rac-diars)] and [PdXY,(meso-diars)](X = C1, Br, or I) have been synthesized using the method previously employed298“for the chloro-complex. Their configurations were confirmed from ‘H n.m.r. and i.r. data.298aAlso reported are the five-co-ordinate compounds [PdXL]’ [(X = C1, Br, I, or SCN; L = (71a)l. Trigonal-bipyramidal geometry was indicated

Sb

by the u.v.-visible spectra, which also showed an interesting shift of the ligandfield bands to higher energy in the order I > Br > C1. It was suggested that this nephelauxetic behaviour arises from compression of the Pd-Sb linkage as a result of ~ h e l a t i o n . ~ ~ ~ ’ Group I V Donors. The reaction of cis-[Pd(PPh,)(PhNC)Cl,l with phenyl derivatives of heavy metals, YPh (Y = HgPh, PbMe, PbPh,Cl, SnPh,, or BiPh,), has been shown to yield an N-phenylimino-complex: PhjP

\

C1

/

Pd

PhNC’

NPh /CI\ /CCPh Pd Pd PhN=C/ \Cl’ \PPh, Ph3P\

+ 2YPh - 2YCI

\C1

I

Ph

This compound undergoes a range of bridge-splitting and reversible protonation reactions (Scheme 20).

F\Pd/ C\=NPh Ph -

Ph3P\

Pd

P~N=C/

‘d

\PPh,

HCI NEt,

I

Ph

PhN

$ /

Ph

1

PhHN

PPh3

C -Pd

I

-CI

-

$

HCIO,

PPh,

PPh3

c104

C-Pd-Cl / / Ph P P h ,

OH -

L

trans

1

-I

Scheme 20 R. G. Cunningham, R. S. Nyholm, and M. L. Tobe, J.C.S. Dalton, 1972, 229. A. J . Cheney and €3. L. Shaw, .I. Chem. SOC.( A ) , 1971, 3549. 29ebL. Baracco and C. A. McAuliffe, J.C.S. Dalton, 1972,948. 2 9 9 B. Crociani, M. Nicolini, and T. Boschi, J . Organometallic Chem., 1971, 33, C81.

19’

29’0

The Noble Metals

415

Table 5 X-Ray data for palladium compounds

trans-[Pd(CNBu‘)J,]

Ref: R Comments a 0.041 Determined with improved accuracy. b 0.13 Pd bonded to four S atoms in essentially a square plane. C 0.093 trans square plane confirmed. Isonitrile groups, Pt-N-C-But, are linear. d 0.060 Tetrahedrally distorted from square plane owing to steric effects. Also rectangular distortion caused by ‘bite’ of bipy. e 0.12 Tetrahedral distortion from square plane. 0.038 cis-square-planar co-ordination. f Five-membered chelate ring of rneso2,3-diaminobutane is puckered with one methyl group equatorial and one axial. 0.058 Square-planar arrangement of two 9 terminal and two bridging azide N atoms about each Pd.

N

I N

I

N-N-N

N \ /

N-N-N.

Pd

N-N-N

/ \

\

/

-N-

I

Pd

/

\

’N-N-N

N

I

N [Pd(C,H,SAsMe,),],C,H,N [Pd(S4C,H4)]

0.105 trans square planar structure, with bidentate thiol. Pyridine molecule is clathrated. 0.064 Contains novel arrangement of two square-planar Pd-bis(ethylene-172dithiolene) units joined by a direct Pd-Pd bond (2.79 A). H r -S\pd,S

HC -S’

1

-7H

‘S-CH

416


Table S-continued [PdPhNC(OMe),(PPh,)]

[Pd( P hNC(OE t )S>2] [PdC1(Me3dpma)]C1

0.083 Square-planar co-ordination about Pd. One thiocarbamate ligand coordinates through both S and N, while other is unidentate through S. 0.089 Approximate square plane about Pd. Both thiocarbamates are bidentate, bonding through S and N. 0.042 Distorted square plane.

j

k 1

Me

Q-kAN> I

H,C -N-CH,

c1

Me

Me

0.128 Approximate square plane about Pd. Non-bridging pentafluorobenzenethiolato linands are trans. 0.030 Square plane of two C1 atoms and 2 C atoms of novel -C-N-N-Cchelate skeleton about Pd. Shows that previous formulation as

I

(MeNC ),Pd

Pd(S2PPh,),,PPh3 Pd(S2PPh2),,2PEt,

\

/

N A

m n

1

Pd(CNMe ) 2 CI2,2HC1

is incorrect. incomplete Four-co-ordinate, containing one bidentate S,PPh2 ligand. incomplete Four-co-ordinate, containing one bidentate and one unidentate S2PPh, ligand.

0 0

( a ) R. H. B. Mais, P. G. Owston, and A. M. Wood, Acta Cryst., 1972,B28,393;(b) A. Mawby and G. E. Pringle, J . Inorg. Nuclear Chem., 1972,34, 2213:(c) N. A. Bailey, N. W. Walker, and J. A. W. Williams, J . Organometallic Chem., 1972,37,C49:(d) A. J. Carty and P. C. Chieh, J.C.S. Chem. Comm., 1972,158:(e) M.Hinamoto, S. Ooi, and H. Kuroya, J.C.S. Chem. Comm., 1972,356;(f)T.Ito, F. Marumo, and Y. Saito, Acta Cryst., 1971,B27, 1695;(9)ref. 294:(h) J. P.Beale and N. C. Stephenson, Acta Cryst., 1972, B28, 557; C H SAsMe, = dimethyl-o-thionophenylarsine;(i) ref. 282: (j) C. Furlani, T. Tarantelli, L. Gastalk,\nd P. Porta, J . Chem. SOC. (A), 1971, 3778; PhNC(0Me)S = O-methyl-N-phenylthiocarbamato; (k)L. Gastaldi and P. Porta, Ga-zetta, 1971.48,641;(I) ref. 293; Me,dpma = methyldi-[(6-methyl-2-pyridyl)rnethyl]amIne; (m) R. H. Fenn and G. R. Segrott, J.C.S. Dalton, 1972,330;( n )W.M.Butler and J. H.Enemark, Inorg. Chem., 1971,10,2416;Me,C,N,H, = 2,5-di(methylamino)-3,4-diazacyclopentadiene : ( 0 )ref. 281.

H2O PH 4

H2O

Trieth ylenetet ramine

Cl Br

PdlVL; -

Pd"L2

Complex Pd"L Pd"L,

Comments Aspartate chelates are slightly more stable than corresponding glutamate chelates. u.v.-visible Composition PdL, determined by spectra equilibrium-displacement method, from decrease in intensity of Pd2+-Arsenazo indicator system when L added. redox potentiometric Instability constants are greater for Pd than Pt. method

Method of study potentiometric tit ration

c

h

Ref. a

(a) M. K. Singh and M.N. Srivastava, J . Inorg. Nuclear Chern., 1972,34,2067; (b) M. I. Shtokalo and V. V. Lukachina, Russ. J . I n o r g . Chem.. 1971,16, 1334; (c) V. I. Dubinskii, Russ. J . Inorg. Chern., 1971, 16, 607.

Solvent H2O

Stability constant data for palladium complexes

Ligand Aspartic acid Glutamic acid

Table 6


418

Table 7 1.r. structural studies of Pd" complexes Complex

trans-[ PdX,py,] trans-[ PdX2(4-Mepy),] (X = C1 or I) [Pd(t nOH),]CI

,

[Pd(Et,dien)( NCL)] BPh, [Pd(Et,dien)(LCN)]BPh, (L = S or Se) [Pd(dien)X] BPh, (X = SCN, SeCN. C1, Br. I, NCO, N,, or NO,) trans-[PdX,(Me,S),] trans-[ PdX,(Me,SO),] (X = C1 or Br) [Wmta),X,] (X = C1 or Br)

[Pd(2-mercaptoethylamine),] [Pd(N1V-dimethyl-2mercaptoethylamine),] [Pd( 3-mercaptoethylamine),]

trans-[PdM,(py )21 tr~ns-CPdM~(3-Mepy)~l rmns-[ Pd M ,(4-Mepy),] [M=Mn(CO),. Co(CO),, or Cp(M O( CO),]

Other studies Also Pt

Results and Conclusions Assigned v(M-X) and v(M-N) bands.

Ref: a

Assigned ~ ( 0 - H ) in complex. 'H N.m.r. indicates chelate ring is in chair conformation with OH axial. Assign all bands and performed Also Ni, Pt a normal co-ordinate analysis. v(M-N) decreases in order Pt > Pd > Ni, suggesting same trend for strength of co-ordinate bonds. Assigned Pd-NCS, (365 cm- '), Far i.r. Pd-NCSe, (360 cm- I ) , only Pd-SCN (320 cm-I), and Pd-SeCN (318 cm- ') bands for these complexes. Followed linkage isomerism using far i.r. Assigned bands by observing Raman, X-ray powder shifts between hydrogenated and deuteriated derivatives. patterns Low-frequency i.r. shows that Cu, Ni, Pt 'I mta ligand is bidentate, and X is not co-ordinated. Configurations of the PdN,S, Ni skeleton determined by observed number of Pd-N and Pd-S stretching bands. Band assignments based on isotopic substitution of Pd and amino-groups.

'H n.m.r.

Pt

Obtained stretching frequencies for Pd-M bonds. These are weaker than corresponding Pt-M bonds.

b

c

d

e f

g

h

(a) M. Pfeffer, P. Braunstein, and J. Dehand, Inorg. Nuclear Chem. Letters, 1972, 8, 497: (b) T. G . Appleton and J. R. Hall, Inorg. Chem., 1972, 11, 117; tnOH = H,NCH,CH(OH)CH,NH,: ( c ) A. Bigotto, V. Galasso, and G. De A l t i Spectrochim. A c t 4 1971,27A,1659; GM = glyoximate; (d) J. L. Lauer, M. E. Peterkin, J. L. Burmeister, K. A. Johnson, and J. C. Lim, Inorg. Chem., 1972, 11, 907: Et,dien = Et,NCH,CH,NHCHZCH,NEt,: ( e ) M. Tranquille and M. T. Forel, Spectrochim. Acta, 1972, B A , 1305; ( f ) M. Ikrarn and D. B. Powell, Spectrochim. Acra, 1971, 27A, 1845: mta = 2-methylthioaniline; (g)C. W. Schllpfer and K. Nakamoto, Inorg. Chim. Ada, 1972,6, 177; ( h ) P. Braunstein and J. Dehand, J.C.S. Chem. Comm., 1972, 164.

The Noble Metals

419

Following a preliminary details have appeared of the preparation of the complex [Pd(CO)(SnCl,),Cl] -. Also reported are the compounds (AsPh,) [Pd(CO)(ROH),(SnCl,),Cl] (R = Me or Et), and their substitution reactions with N, P, As, and Sb donor ligands.," Palladium(Iv).--Reaction of quinazoline-2,4-dithione [LH(5l)] with PdC1, in acetone-butanol solvent has yielded the red-brown [PdL,Cl,]. 1.r. studies support bidentate co-ordination of the ligand through both S, and N donors.254

6 Platinum

,-

Cluster Compounds.-Unusual mixed cluster compounds of the type [MPt (CO),L:] and [M,Pt(CO),Li] (M = Ru or 0 s ; L' = PPh,, PMePh,, PMe,Ph, or AsPh,; L2 = PMe,Ph) have been prepared via the reaction of M3(CO)12with PtL,. The structures (2) and (3) were proposed from i.r. studies. On the other hand, clusters of the general form [Fe,Pt(CO),L,] (72) and [Fe,Pt(CO),L] (73) were obtained from the corresponding reaction with Fez(C0)9.'0' 301a An X-ray analysis of [Fe,Pt(CO),(PPh,)] confirms the structure suggested from i.r. and 'H n.m.r. data, with square-planar co-ordination about Pt (see Table 8).302 L

L

Fe(CO),

'Pt/ L

Fe(CO),

I

Fe(CO),

A third type of cluster, [FePt,(CO),{P(OPh),},], was isolated from the reaction between Fe,(CO), and [Pt{ P(OPh),},], for which the structure (73a) was proposed.301* These clusters join a growing number of such compounds which do not obey the effective atomic number rule.

I

Pt (C0)L

L (COl3Fe'

\

Pt (C0)L

Platinum(O).-Group VIDonors. An '*Oisotopic i.r. study has been carried out on a number of molecular oxygen complexes, including [Pt(O,)(PPh,),]. The results confirm oxygen co-ordination to be a side-on isosceles structure. Assignment of the P t 4 stretching vibration was made for the first time, J. V. Kingston and G. R. Scollary, Chem. Comm., 1970,362. J . V. Kingston and G. R. Scollary, J . Chem. SOC.( A ) , 1971,3765. 301aM.I. Bruce, G. Shaw, and F. G. A. Stone, J.C.S. Dalton, 1972, 1082. 302 R. Mason, J. Zubieta, A. T. T. Hsieh, J. Knight, and M. J. Mays, J.C.S. Chem. Comm., 1972, 200. 300

301

420


and from the overall study the M-0 stretching force constants were correlated with the reactivity of the 0, ligand.',' An X-ray analysis (see Table 8) of [Pt(0,)(PPh3),],2CHC13 supports the square-planar structure (74), and indicates an 0-0 distance (1.505 A) similar to that found with other transition

metals which take up oxygen irre~ersibly.,'~These results cast doubt on an earlier X-ray study of the toluene adduct [Pt(O,)(PPh,),],PhMe, which suggested a very short (1.26A) 0 4 bond.304 Reaction of quinazoline-2,4dithione [LH (51)] with [Pt(PPh,),] has produced the yellow [Pt(LH),(PPh,),]. Unidentate co-ordination of the ligand via a sulphur atom was confirmed from the i.r. spectrum. This complex undergoes oxidative addition with HNO,, yielding [PtH(LH),(N0,)].2 5 4 Group I/ Donors. Phosphorus and arsenic donor ligands. The photochemical or thermal reaction of [Pt(APh,),(CO),] (A = P or As) with reagents X in ethanol, has been shown to be a convenient route to a series of complexes of the t y p [Pt(APh,),X] (X = PPh,, C2H4, or PhC=CPh) and [Pt(APh,),(CO),]. In the absence of added ligands, the reaction yields the orange dimer [Pt(PPh3),],. Evidence suggests [Pt(APh,),] as an intermediate in these processes.,05 The complexes [Pt(BuOPPh,),Cl,], [Pt(BuOPPh,),], and [Pt(MeOPPh,),] have been reported, together with their reactions with protonic acids to yield labile hydrido-species (from 'H n.m.r.). On standing in ethanol in the presence of free ligand, [Pt(BuOPPh,),] gave a quantitative precipitate of [Pt(OPPh,),(HOPPh,),]. Substitution of this latter complex with phosphites provided further new species of the type [Pt(OPPh,),HOP(OR),], (R = Ph or p - t ~ l y l ) . ~An ' ~ interesting new complex is the yellow [Pt(NO),(PPh,),] isolated from the reaction of NO on [Pt(PPh3),] ( n = 3 or 4).The i.r. spectrum of this air-stable solid showed no bands attributable to terminal NO groups. However, strong bands at 1285, 1240, and 1062 cm-' suggested the presence of a hyponitrite ligand, which was confirmed from the reaction:

In the absence of X-ray data, the alternative structures (75) and (76) were proposed.307 P. T. Cheng, C. D. Cook, S. C. Nyburg, and K. Y. Wan, Canad. J . Chem., 1971,49, 3772. C. D. Cook, P. T. Cheng, and S. C. Nyburg, J . Amer. Chem. SOC.,1969,91, 2123. 3 0 5 D. M. Blake and R. Mersecchi, Chem. Comm., 1971, 1045. 306 P. C. Kong and D. M. Roundhill, Znorg. Chem., 1972, 11, 749. 30' S. Cenini, R. Ugo, G. La Monica, and S. D. Robinson, Inorg. Chim. Acfa, 1972, 6 , 182.

303

304

The Noble Metals

42 1

(75)

(76)

The oxidative addition of p-substituted diazonium salts to [Pt(PPh,),] under heterogeneous conditions has provided the series of complexes [(PPh,),Pt-N=N-C,H,R-p]X (R = NO,, F, H, OMe, or Me, X = BF,; R = NMe, or NEt,, X = BPh,); Scheme 21 shows some of their reaction^.^" [PtH(PPh,),]+

H3/* /

+ C6H,R + N,

c y [Pt(PPh,),(OH)];+

[(Ph,P),Pt(N=NC,H,R)]

+

+ HOC,H,R + N, + PPh,

[Pt(PPh,),(NH=NC,H,R)]''

\[Pt(PPh,),N,(N=NC,H,R)]

(X

=

BF, or C10,)

+ PPh,

Scheme 21

Following a recent report258 of the de-arylation of organic azides by [Pt(PPh,),], similar results have been described for methyl and ethyl azides yielding [Pt(N,),(PPh,),].25 Group IT/ Donors. A new class of Pto complex of the formula [Pt(PPh,),(CNBu')] has been isolated from the reaction between [Pt(PPh,),(C,H,)] and free isocyanide. Further treatment with CO gave [Pt(PPh,),(CNBu')(CO)], and comparison of the v(NC) frequencies in these two new complexes suggests that CO is a more effective x-acceptor than the isoelectronic isocyanide. Oxidative addition reactions were also r e p ~ r t e d . ~ " [Pt(PPh,),(CNBu'),]

+ XY

[Pt(PPh3)2(CNBu')2XY]

(XU= I,, MeI, CF,I, or Ph,SnCl)

Treatment of [Pt(PPh,),] with SiF, in benzene has provided the adduct [Pt(PPh,),SiF,], which may be regarded as a model for the intermediates probably formed during oxidative addition reactions. Its i.r. and n.m.r. spectra are consistent only with five-co-ordinate Si, and rule out simple oxidative products of the type [Pt(PPh,),(SiF,)F].30gu Similar reactions yielded the related adducts Pt(PPh3),,2BC1, and Pt(PPh,),,2A1Me3. A trigonal-bipyraS. Cenini, R. Ugo, and G. La Monica, J . Chem. Soc. ( A ) , 1971, 3441. G. A. Larkin, R. Mason, and M. G. H. Wallbridge, Chem. Comm., 1971, 1054. 3090T. R. Durkin and E. P. Schram, Znorg. Chem., 1972, 11, 1048. 308

309


422

midal geometry was proposed for the BCl, complex, and some reactions are described.

''

Platinum(I).--Few compounds of this oxidation state are known. However, the reaction between [(Me,Si),Hg] and excess [PtCl,(Ph,PCH,PPh,)] has given a yellow product believed to be the Pt' d i m a [Pt,Cl,(Ph,PCH,PPh,),]. Its i.r. and 'H n.m.r. spectra indicate only bridging Pt-Cl groups, suggesting the structure (77). Since the complex is diamagnetic and gives no e.s.r. signal, Ph2 P

/ \

H2C

/

Pt

Ph2 P

CI

/ \

\

Pt P

the structure involves either two d9 Pt' atoms with significant Pt-Pt action, or two Pt atoms in different oxidation s t a t e ~ . , ~ ~

inter-

Platinum(I1). Group VII Donors. Halogeno-complexes. The mixed di 11alide complexes of Pt", e.g. [PtICl], have been prepared via the action of the interhalogen compounds ICl, IBr, BrCl, on Pt black. X-Ray diffraction studies show that they are distinct compounds and not mixtures of homogeneous Pt dihalides311 An alternative route to [PtBrCl], has also been described involving the metathetical exchange reaction between PtCl, and BBr,. The far4.r. spectrum of the complex, believed to be Pt,Br,Cl,, showed both Pt-CI and Pt-Br bands.,' la Solid-state emission spectra have been measured for a series of n-complexes, ranging from the low-field [PtC1,J2- to the highfield [Pt(CN),]'-. Whereas the low-field complexes exhibited both d-d and charge-transfer bands, only intense charge-transfer bands were observed with high-field compounds. However, for both types the luminescence appears to be associated with a weak long-wavelength absorption., l 2 Molecular orbital calculations have permitted the prediction of the lineshape of the magnetic c.d. of [PtCl,], -. Agreement with experiment allows assignment of the electronic transitions in this complex.263 Hydridophosphine complexes. A large number of hydrido-complexes of the type [PtHX(PPh,),]ClO, (X = CIO,, PPh,, SbPh,, C,H,, C,H,, or CO) have been prepared using the reaction: [PtHC1(PPh3),]

+ AgClO,

AgCl

+ [PtH(C104)(PPh,),] Ix

I [PtHX(PPh3123

309bT. R. Durkin and E. P. Schram, Inorg. Chem., 1972. 11, 1054. F. Glockling and R. J. I. Pollock, J.C.S. Chem. Comm., 1972,467. S. S. Batsanov and L. A. Vostrikova, Rurs. J . Inorg. Chem., 1971, 16, 1792. 3110P. M . Druce and M. F. Lappert, J . Chem. SOC.( A ) , 1971, 3595. 3 1 2 D . L. Webb and L. A. Rossiello, h o r g . Chem., 1971, 10, 2213. 310

311

The Noble Metals

423

Further treatment of [PtH(CO)(PPh,),] with amines and thiourea yields other [PtHY(PPh,),] (Y = NH,, NH,Me, NH,Et, NHMe,, py, or tu). Concurrent studies of the substitution of X or Y suggest the following order of increasing stability for the hydrido-complexes: C104 < C2H4, C,H, < CO < PPh,, SbPh, < NH,, amines C1 < Br < I < CN. The anomalous position of the amines is probably related to the fact that the trans H is only a donor and cannot enter into donor-acceptor interaction^.^'^ The preparation of some related complexes, trun~-[PtHX(PR,)~l(X = C1, Br, I, or NCS; PR, = PMePh, or PMe,Ph), has also been reported. Using a reaction sequence similar to that above, the bromo-member trans-[PtHBr(PMePh,),] has been a useful starting material for the synthesis of other trans-[PtHL(PMePh,),] (Y = 2-Mepy, 2,4,6-Me3py, PMePh,, or p-MeC,H,NC). Detailed 'H n.m.r. studies on these complexes allowed comparison of the relative trans effects of the ligands L.,14 In three related investigations,, 15the broadening of the hydridic 'H n.m.r. resonance in trans-[PtHXL,] [X = NCO, NCS, NCSe. or CN; L = PPh,, PBu,, PEt,, AsEt,, PEtPh,, or P(p-tolyl),] has been shown to be due solely to ligand exchange, and not to quadrupole coupling with N as previously suggested., l 7 Furthermore, linkage isomerism was only observed for the CNS complexes, which again disagrees with the previous study which proposed similar isomerism for the CNO compound. The NCS: SNC ratio increased in the order Et,P Bu,P < Et,As < Ph,EtP < Ph,P, which is probably due to steric crowding favouring the linear N-bonded isomer over the bent Pt-SCN group. Halogenophosphine complexes. Follow a preliminary communication3 '' details have appeared of the preparation of the bridged dinuclear cations (78) and (79). Structures were assigned from i.r., "B n.m.r., 31P n.m.r., and conduct-

-=

-

Pt-

Pt.

Bu,P (78)

X X

=

PBu, I . C'I. Hr

(79) Y

=

C1, Br, NCO, N,

itivity data. The complexes readily decomposed in cold water yielding cis[PtX,(PBu,),] or ~is-[PtY,(PBu,),l.~'' Bridge-splitting reactions of the (R = Et or Ph) have yielded the new related dimers [Pt,Cl,(PR,),](BF,) I. V. Garrilova, M. I. Gel'fman, N. V. Ivannikova,and V. V. Razumovskii, Russ. J . Znorg. Chern., 1971, 16, 596. 3 1 4 H. C. Clark and H. Kurosawa, J . Organometallic Chem., 1972, 36, 399. 3 1 s M. W. Adlard and G. Socrates,J.C.S. Chem. Comm., 1972, 17. 3 1 6 M. W. Adlard and G. Socrates,J . Znorg. Nuclear Chem., 1972, 34,2339. 316aM. W. Adlard and G. Socrates, J.C.S. Dalton, 1972, 797. 31' J. Powell and B. L. Shaw, J . Chem. Soc., 1965,3879. 3 1 8 P. M. Druce, M. F. Lappert, and P. N. K. Riley, Chem. Comm., 1967,486. P. M. Druce, M. F. Lappert, and P. N. K. Riley, J.C.S. Dalton, 1972,438. 313

424


complexes cis-[PtClpy(PEt,),]BF, and [PtCI(PPh,),]. On the other hand, treatment with aldehydes gave the known trans-[PtCl(CO)(PEt,),IBF,, whereas formic acid was catalytically decomposed. These reactions provide the closest reactivity parallel yet observed between the d8 ions of the Pt and Rh groups.266 Similar bridge-splitting processes have been independently used to prepare the new cationic series trans-[PtX(CO)L,]BF, (X = anions: L = PEt,, PPh,, or PMe,Ph), and cis-[PtClYL,] (Y = SCN, NO,, or NO,). The geometries were suggested from their 'H n.m.r. spectra. A detailed study was made of the effect of the trans influence of X on the reactivity of the trans[PtX(CO)L,]BF, complexes.320 A large number of tertiary t-butyl- and o-tolyl-phosphine complexes of the type trans-[PtX,L,] (X = Cl, Br, or I) have been prepared as part of a continuing study of bulky phosphine complexes. The bulky substituents were found to promote internal Pt-4 bond formation, yielding complexes of the type trans-[PtX(P-C)L] (P-C = internally metallated phosphine). It is interesting that the corresponding Pd complexes show no such tendency, perhaps' owing to the reluctance of Pd" compounds to undergo oxidative addition to give Pd" intermediate^.^ '' A preliminary account has appeared.322 Of more theoretical interest, a 31P n.m.r. study of these and related complexes has revealed a linear correlation between the chemical shift of the free . ~ ~ unusual, phosphine and the change in chemical shift on ~ o - o r d i n a t i o nThe temperature-dependent asymmetry of the lowest energy ligand-field band of the trigonal-bipyramidal complexes [PtX(L'L:)]+ [X = C1, Br, I, or CN; L'L: = (Me,AsC,H,),L' (L' = P or As), or (0-MeLC,H,),P (L = S or Se), or (0-Ph,LC6H,),L' (L' = L = P or As)] has been explained in terms of permanent ground-state distortion. Group VZ Donors. Detailed conformational studies have been made on the complexes [PtX(AMe,Ph)(OOCR)], (X = C1, Br, or I; A = P or As; R = Me, CH,Cl. CH,Br, CCl,, CF,, CMe,, or CPh,), which were prepared by addition of Ag0,CR to the appropriate [PtX,(AMe,Ph)],. Their i.r. spectra confirm the presence of bridging carboxylate groups, and their 'H n.m.r. suggest the structure (52a; M = Pt). Variable-temperature 'H n.m.r. measurements showed conformational averaging at higher temperatures. The low E, (3-6 kcal mol-') and large negative A S (-20 to -40 e.u.) were interpreted in terms of an exchange process involving rapid solvolysis of a Pt-0,CR bond to give a mono-p-0,CR intermediate, rather than a simple inversion of the Pt,C,O, ring.268"A study of the reactions of the related complexes [Pt(PPh,),(O,CR),] (R = Me or CF,) with CO and SO, in alcoholic media has suggested a mechanism involving the formation of an intermediate alkoxide complex (Scheme 22).268b A study of the acid properties of the water molecule in the complexes cis320

321

322

W. J . Cherwinskii and H. C. Clark, Inorg. Chem.. 1971, 10, 2263. A. J. Cheney, B. E. Mann, B. L. Shaw, and R. M. Slade, J . Chem. SOC.( A ) , 1971, 3833. A . J. Cheney, B. E. Mann, B. L. Shaw, and R. M. Slade, Chem. Comm., 1970, 1176.

The Noble Metals

425

[Pt(a-alaninate)(H,O)L]+ (L = NH,, py, Et,S, or DMSO) has shown that the acidity varies greatly with the nature of the cis-L. As expected, the n-donor NH, causes the weakest acidic properties, whereas n-accepting ligands produce a marked increase in K , for the water.323Similar studies on trans-[Pt(DMSO)ClL(H,O)]+ indicate that the acid strengths decrease in the order L = NH,OH > acetoxime > a ~ e t a l d o x i m e . ~ ~ ~ [Pt(PPh,),(O,CR'),]

+ R20H(R2= Me or Et)

-[Pt(PPhJ2(0R2)(O2CR1)]

/ co

1SO.

[Pt(PPh3),(O2CR1)(O,CR2)][Pt(PPh3),(S0,0R),] Scheme 22

Variable-temperature 'H n.m.r. data on the chelates [PtX,(RSC,H,SR)] (X = C1, Br, or I; R = Me, Et, Pr, Pr', or Bu) have been interpreted in terms of inversion at S between the meso and (+)-isomeric forms (59a; M = Pt). The rate of inversion increased with increasing trans influence of X,and was slower A preliminary account has than for the corresponding Pd appeared. 7 9 b A range of alkylsulphoxide complexes of composition [PtL4](C10,), and [PtCl,L,] (L = DMSO, DESO, C,H,SO, dipropylsulphoxide, or di-isoamylsulphoxide) have been prepared via direct reaction between L and K,PtCl,. 1.r. studies show that many of these, including [Pt(DMSO),](C1O4),, contain both S and 0 co-ordination sites. It was further observed that 0-bonded sulphoxides exchanged rapidly with free L, whereas S-bonded ligands were relatively inert.273The thio-oxinato-complex [Pt(C,H,NS),] (54; M = Pt) has been isolated and its N and S co-ordination confirmed from i.r. data.274 Similarly, bidentate bonding of the ligand through both N and S , donors has been confirmed for the quinazoline-2,4-dithione [LH (51)] complex [PtL,]. This red-brown compound was prepared from the action of LH on PtC1, in acetone-butanol solvent.254New 2-benzothiazolethiol [LH (56)] complexes of the type [PtL,]. [PtCl,(LH),], and [Pt(NH,),] have been isolated employing Scheme 19 (M = Pt). In contrast to the preceding complexes, i.r. and 'H n.m.r. studies indicate that the ligand is only bidentate (S, and N bonded) in [Pt L,]? The complex [Pt(Me(SNH,),]Cl, has been synthesized from the reaction between [K,PtCl,] and thioacetamide. Its i.r. spectrum confirms that the ligand is unidentate and co-ordinates uiu the S group.188On the other hand, the ligand thiovanol (CH,SHCHOHCH,OH) forms the diamagnetic [PtL,], whose u.v.-visible and i.r. spectra suggest a square-planar structure with bidentate ligands.' 89 A related study describes the synthesis of the Schiff-base Other new complexes (57) and (58) (M = Pt; X = C1, Br, I, NCS, or complexes prepared are the diamagnetic [Pt(SSeCNR,),] (R = Me or Et) 323 324

Y. N. Kukushkin and G . P. Gur'yanova, Russ. J. Inorg. Chem., 1971, 16, 580. Y. N. Kukushkin, A. I. Stetsenko, V. G . Duibanova, and S. G. Strelin, Russ. J. Inorg. Chem., 1971, 16, 1632.

426


species, via the action of [Me,SnCl(SSeCNR,)] on [PtC1,I2-. These orangered complexes contain both Pt-S and Pt-Se bonds.279 Insertion of SO, into the Pt-C bond of trans-[Pt(Ph)C1L2] has provided the series of S-sulphinate complexes trans-[PtClL,(SO,Ph)] (L = PEt,, AsEt,, SeEt,, or TeEt,). The position of the v(Pt-Cl) frequencies confirms the geometry and indicates a medium trans effect for S0,Ph.325 Carbon disulphide has also been shown to insert into the Pt-F bond of [PtF(PPh,),]+, yielding a complex which has been assigned the structure (80) from X-ray studies (see Table 8).326In view of this result, it is probable that the complex [PtCl(S,CH)(PPh,),], recently obtained by CS2 insertion into a Pt-H bond,327 has an analogous ionic structure.

Ligand-exchange reactions have yielded a series of mixed dithiolene complexes of the type [Pt{S2C2(CN)2)(S,CNR,)]- (R = Et, Bu, or Ph). Voltammetric studies in CH,Cl, revealed that the complexes could undergo oneelectron oxidations, the half-wave potentials of which were intermediate between those of the unmixed complexes.272An interesting new facet of dithiolene chemistry has arisen from an X-ray study (see Table 8) of the complex [Pt(S2C2H2)2]. It was shown to have a dimeric structure (62; M = Pt) containing a very short Pt-Pt bond (2.77 A). This novel arrangement is distinct from the laterally displaced dimeric structures exhibited by several other bis(dithio1ene) complexes where interaction is via M-S bonds., * Coloured, diamagnetic complexes of the type (81) have been isolated from the reaction of l-phenyl-

4-mono- or di-substituted thiosemicarbazides with Pt’” salts. Electrochemical and e.s.r. studies have shown these to be the central species of a rare five325

326

321

F. Faraone. L. Silvestro. S. Sergi. and R. Pietropaolo. J . Organornetallic Chem.. 1972,34, C55, J. A. Evans, M. J . Hacker, R. D. W. Kemmitt, D. R. Russell, and J. Stocks, J.C.S. Chem. Comm., 1972, 72. A. Palazzi, L. Busetto, and M. Graziani, J . Organornetallic Chem.. 1971, 30, 273.

The Noble Metals

427

membered electron-transfer series [PtL,]', whose component species ( z = - 2, - 1, 0, 1 +, 2 +) are interrelated by one-electron transfer reactions.328 The cis- and trans-isomers of [PtX,(R,S),] (X = C1, Br, or I; R,S = Et,S, C4H,S, or C,H,,S) have been prepared and their i.r. Raman spectra recorded, allowing assignment of their fundamental modes.32 9 Group V Donors. Nitrogen donor ligands. A series of complexes of the unusual 1,3-diaryltriazenido ligand (9) has been prepared, including [Pt(PPh,),L,] (L = 1,3-di-p-tolyltriazenido). The i.r. spectrum of this diamagnetic solid indicates unidentate co-ordination of L.62 The metathetical reaction between K(C,N,) and [PtCl,X(PPh,),] (X = Cl or H) has yielded the dicyanoketiminato-complexes [PtX(C,N,)(PPh,),]. A N-bonded structure (33; M = Pt) is ~ u g g e s t e d . An ' ~ ~interesting preparative and spectral study of the complexes trans-[PtX,(Me,N),] and (Pr,N)[PtX,(NMe,)] (X = C1 or Br) has shown that NMe, generates a weaker trans influence than the corresponding phosphine and arsine, and lies below ammonia in the spectrochemical series.284 The treatment of K,[PtCl,] with benzoylhydrazine (LH) has provided the complex [PtCl,(LH),], whose i.r. spectrum and conductivity suggest the structure (82).The corresponding reaction with K2[ Pt(SCN),] gave [Pt(SCN),0

II

PhCNHNH

\,Pt/C1 /

\

c1

PhCNHNH,

II

0 (82)

(LH)], for which a bridging structure (83) was proposed. It was possible to convert [PtCl,(LH),] into [PtL,] (84) in which the ligand is bidentate, by 0

II

PhCNHNH

NCS

\

\ 2 /

NCS

/

Pt

\

/

SCN

Pt

/

SCN

\

0

II

NH,NHCPh

the addition of NaOH. Thus both keto and enol forms of the ligand are observed in its complex.330 The synthesis and characterization of the ethylenediamine-bridged dimers [PtX,(CO),en] (X = C1 or Br) have been reported. Their i.r. spectra support 328 329

330

C. E. Forbes, A. Gold, and R. H. Holm, Znorg. Chem., 1971, 10,2479. E. A. Allen and W. Wilkinson, Spectrochim.Acta, 1972, 28A,725. Y. Y. Kharitonov and R. I. Machkhoshvili, Russ. J . Znorg. Chem.,1971, 16,604.

428


trans geometry about the ethylenediamine (85).33 Other complexes prepared include [PtLJI, (L = py. 3-pic. 4-pic, 4-Etpy. or 3,5-Me2py). Pyrolysis of these compounds at 100°C for 24 h has provided a convenient route to the series trans-[PtI,L,], which are otherwise difficult to prepare. Their geometry

/

/

\

\

X H,NCH,CH,NH,

X

was confirmed by the presence of only a single v(Pt---I)frequency between 176 and 196 cm-'.332 Also reported is a series of complexes of the ligand isothiazole (861, including cis[PtCl,L,]. By analogy with its pyridine and thiazole analogues the ligand is assumed to co-ordinate through the N atom.333

c

N

s

A number of substituted propane-1,3-diamine (64) compounds of the type [PtL,I2+ and [PtX,L,] (X = C1, Br, or NH,) have been described. Several of the latter species exhibited polymorphism which was attributed to either different H-bonded linkages or different chelate ring conformations in the two forms.286In solution their 'H n.m.r. spectra are consistent with a preference Similar 'H n.m.r. for a chair-type conformation with the C1 or O H spectral studies have also been reported for some related N-methyl substituted DMSO\

, C1

C1

\

/

DMSO

/ P t \ A /Pt\ C1 HN

wNH

331 332 333

T. Theophanides and P. C. Kong, Inorg. Chim. Acta, 1971, 5, 485. G . W. Watt, L. K. Thompson, and A. J. Pappas, Inorg. Chem., 1972,11, 747. M . E. Peach and K. K. Ramaswamy, Inorg. Chim.Acta, 1971, 5,445.

The Noble Metals

429

ethylenediamine and propane-1,3-diamine complexe~.~ 3 4 The reaction of K[PtCl,(DMSO)] with a variety of secondary heterocyclic amines has been investigated in detail. Morpholine, piperidine, and aminoadamantane yielded the complexes trans-[PtCl,(amine)(DMSO)] ; with piperazine and anabasine, bridged complexes of the type (87) were obtained. The piperazine complex undergoes a series of interesting reactions shown in Scheme 23. Production of the chloroamine complex (89) demonstrates the similarity between piperazine and ethylenediamine.,,

Cl2 \I

Scheme 23

A r e - i n ~ e s t i g a t i o nof~ ~the ~ reaction of K,[Pt(NO,),] with HNO, at room temperature has shown that the product is K,[Pt(NO,),]. Only with prolonged boiling was the previously reported337 product K,[Pt(NO,)(NO,),] obtained. Of these two compounds, only the latter reacted with KX (X = C1, Br, or I) at room temperature, yielding K,[PtX,]. This difference is undoubtedly associated with the greater lability of the NO, (O-bonded) Similar studies of the action of HI on cis- and trans-[Pt(NO,),(NH,),] have indicated the products trans-[PtI,(NO,)(NH,),] and Cs,[PtI,(NO,)(NH,),],, respectively. Oxidation and reduction experiments showed the latter dimer to contain both Pt" and Pt'", and a bridged structure was proposed by analogy with the known bromo analogue.338In contrast to by HCl, which is the splitting of c~~-[P~(NH,),(NH,CH,CO,H)~]~+ 334

335 336

337 338

339

T. G. Appleton and J. R. Hall, Inorg. Chem., 1972, 11, 125. Y. N. Kukushkin and V. A. Yurinov, Rum. J . Inorg. Chem., 1971, 16,601. L. K. Shubochkin, E. F. Shubochkina, M. A. Golubnichaya, and L. D. Sorokina, Russ. J . Inorg. Chem., 1971,16, 877. 1. I. Chernyaev and L. Y. Jenning, Izvest. Sektora Izuch. Platiny, 1933, 11,46. G. S. Muraveiskaya and I. I. Antokol'skaya, Russ. J . Inorg. Chem., 1971, 16, 868. L. M. Volshtein and I. 0. Volodina, Zhur. neorg. Khim., 1960,5, 35.

430


known339to occur in both cis and trans fashion, the corresponding reaction with HBr has been shown to give only trans-[PtBr2(NH,)(NH2CH2C02H)]. This stereospecificity is consistent with the stronger trans influence of Brcompared to C1-. Titration of the new yellow [PtBr,(NH,)(NH,CH,CO,H)] with alkali yielded the chelate [PtBr(NH3)(NH2CH2C0,)].340An interesting example of the reactivity of co-ordinated hydroxylamine has been reported in a study of the reaction of acetaldehyde with [Pt(NH20H),I2+, and cis- and truns-[Pt(NH,OH),X,]"+ (X = C1 or NH,). The complexes [Pt(MeCH= were obtained, whose i.r. spectra NOH),],' and [PtMeCH=NOH),X,]" confirmed the presence of C=N bonds [v(CN) = 1672 cm-']. These aldoxime complexes are relatively stable in acidic solution, which contrasts with the ready hydrolysis of free oxime molecules.341 The polarized single-crystal absorption spectrum of [PtCl,en] has been redetermined at 77 and 300 K with greater accuracy. Theoretical considerations led to the assignment of two of the bands as unusual transitions to ionized exciton states, based on the excitation of an electron into a d,, (antibonding) orbital from the d,, and ligand 7c-orbitals on adjacent molecules.342 Another study reports the u.v.-visible solution spectra of cis- and trans[PtX,L,] (X = Cl, Br, or I; L = py. 2-CNpy, 3-Clpy, 4-Clpy, 4-CNpy, 4pentyl py. 3.5-Cl,py. or NH,) together with a complete band assignment.343 Few mass spectral studies have been made of relatively involatile metal complexes. However, a recent study shows that cis- and trrins-isomers of the type [PtX,(PEt,),] can be distinguished by their fragmentation patterns. In contrast, the corresponding ammine and pyridine isomers gave similar patterns, suggesting excitation to a tetrahedral state by electron impact.344 Two related papers have reported the isolation of a series of electron-exchange type complexes [PtX,L,] [PtX4L,] (X = C1, Br, I, or NO,; L = NH, or ten), and the determination of the stability constant for the bromo member. Qualitative observations suggest that the strength of the cation-anion bonds increases in order C1 c Br c I.345.346 Interest in the electrical conductivity of metal-chain complexes is increasing. Several studies have been made of the mixed valence complex K2Pt(CN),Br0., 2.3H20. One reports that the conductivity in the direction of the Pt-atom chain is 100 times greater than at right angles to the chain.347 However, another study indicated considerable experimental scatter, which was attributed to variable water content from sample to sample. Small amounts of water were shown to increase the conductivity by a factor of up to 104.222It has also +

340

341

342 343 344

345 346

347

L. M. Volshtein and L. F. Krylova, Russ. J . Inorg. Chem., 1971, 16, 731. Y. N. Kukushkin, A. I. Stetsenko, S. G. Strelin, and Z. V. Reshetnikova, Russ. J . Inorg. Chem., 1971, 16, 1790. D. N. Martin, L. D. Hunter, R. Kroening, and R. F. Coley, J . Amer. Chem. SOC.,1971, 93, 5433. M. Texter and W. Ludwig, Helv. Chim. Acta, 1972, 55, 184. P. Haake and S. H. Mastin, J . Amer. Chem. SOC..1971, 93, 6823. Y. A. Makashev, F. Y. Kul'ba, and R. A. Zlotnikova, Russ. J . Inorg. Chem., 1971, 16, 1325. Y. A. Makashev, F. Y. Kul'ba, and R. A. Zlotnikova, Russ. J . Znorg. Chem., 1971, 16, 722. P. S. Gomm and A. E. Underhill, J.C.S. Dalton, 1972, 334.

43 1

The Noble Metals

proved impossible to reproduce some high-temperature conductivity experiments on this complex, leading to the suggestion that more attention should be given to characterizing the degree of imperfections in the crystals.348 Similar experimental scatter was observed in conductivity experiments on [Pt(NH,),][PtCl,], varying from sample to sample and with the nature of the preparation. Mass spectral and spectroscopic analysis data showed the presence of small amounts of Pd, Cu, Fe, and Au in the more conducting samples, which suggests that such impurities may substantially alter electrical properties of crystals. These results call for a reassessment of previous assumptions of intrinsic conductivity behaviour in such complexes.349 Electrical conductivity studies have also been reported for K , .,,Pt(ox),,H,O (again with considerable scatter).222This complex was shown to display non-ohmic behaviour in applied electric fields, which was associated with proton injection at the anode. The half-cell reactions associated with this proton migration are of some interest, since they constitute a new solid-state proton battery with a cell potential in the range 0.3-0.5 V.,” Phosphorus and arsenic donor ligands. A general synthesis has been reported for a wide range of cationic phosphite complexes of the noble metals, including [PtL4I2+ and [PtXL,]’ [X = C1 or Br; L = P(OMe), or P(OEt),].82 Reaction of the little-studied ligand diphenylphosphine oxide with K,[PtX,] (X = Cl or Br) has produced the complexes [PtX(PPh,O)(PPh,OH),], [Pt(P Ph O),] n, [Pt X (, PPh O),( P Ph OH),], and [Pt(X(PPh, 0)( PPh 0H)(PEt,)]. 1.r. studies show that the last two complexes have a cis arrangement of one PPh,O and one PPh,OH, giving a symmetrical H-bonded system (67; M = Pt).,’’ Complexes of the type [PtX,L] (X = C1. Br, I, or SCN) and [PtL,Y,] (Y = C1, Br, I, SCN, or C10,) have been prepared with the hybrid ligands (68)-(70). 1.r. data confirm that the [PtX,L] compounds are square planar with bidentate L. However, depending on the nature of Y, the [PtL,Y,] species exhibit a variety of four-, five-, and six-co-ordinate forms containing ,~~ studies both bidentate and unidentate (As bonded) hybrid l i g a n d ~ . Similar with the ligand (90) have produced the complexes trans-[PtX,L,] (X = CI or

,

,

,

Br) and [PtCl,L],. The small shift in v(CN) on co-ordination indicates unidentate bonding uia P for the monomers. However, the i.r. data suggest that L acts as a bidentate bridge in the trimer, for which the structure (91) was 348

349 350

T. W. Thomas, M. M. Labes, P. S. Gomm, and A. E. Underhill, J.C.S. Chem. Comm., 1972,322. L. V. Interrante, J.C.S. Chem. Comm., 1972, 302. F. N . Lecrone and J. H. Perlstein, J.C.S. Chem. Comm., 1972, 75.


432

proposed.351An investigation of the co-ordination behaviour of the potentially terdentate ligand (71) with rPtX,12- has shown that in fact only two As donor atoms bond to the metal. yielding [PtX,L] (X = C1, Br, or I) and [PtL,]-

(c10,),.2 5)8

\

c1 PPh,

\

C1- Pt -NC

A

I

C N

I

CF

Pt-Cl

I

c1

A yellow adduct [Pt(PPh,),CH,I-SO,] has been obtained from the action of sulphur dioxide on [Pt(PPh,),CH,I]. Surprisingly. an X-ray study (see Table 8) revealed an I-SO, bond rather than the expected five-co-ordinate adduct. This result provides a warning that SO, may attach to sites other than the metal in complexes.225 Group ZV Donors. Carbon donor ligands. Several papers have reported the synthesis of new isocyanide complexes. A range of [PtXL,(CNR)]PF, complexes have been prepared by the action of alkyl and aryl isocyanides and AgCl on [Pt,X2L4](PF6), (X = C1, I, or Me; L = PMePh, or PMe,Ph). Direct reaction between ci.s-[PtCl,L,] and RCN, on the other hand. yielded [PtL2(CNR),I2+.Ix., Raman, 'H n.m.r., and Mossbauer studies are reported for these compounds, showing RNC to be a weaker n-acceptor than C O or p h ~ s p h i n e s5 .2 ~The facile replacement of labile acetonitrile in the complex [Pt(PPh,),(CNMe)(NCMe)](BF,), has provided a useful synthetic route to a wide variety of new compounds:353 [Pt(PPh,),(CNMe)(NCMe)l2+ L CHzC'z [Pt(PPh3),(CNMe)Ll2

[L [Pt(PPh,),(CNMeMNCMe)l2

+

=

+

Me,N, py, PPh,, PEt,, P(OMe),, Me,S, or MeNC]

+-'-X

[Pt(PPh,),(CNMe)X (X

=

3'

C1, I, CN, N,, NO,, or OH)

Also reported are the syntheses of the related species [PtX,(CNMe),], [PtX,(CNMe)L]. [PtX(CNMe),L]X, [PtX(CNMe)L,]X [Pt(CNMe),](BF,),, and 351

3s2 3s3

D. H. Payne and H. Frye, Inorg. Nuclear Chem. Letters, 1972, 8, 73. H . C. Clark and L. E. Manzer, Inorg. Chem., 1972, 11, 503. P. M. Treichel and W. J. Knebel, Inorg. Chem., 1972, 11, 1289.

The Noble Metals

433

[Pt(Ph2PC,H,PPh,XCNMe)2]2 +.The reactions of the diphos complex were studied in detail (Scheme 24). Some of these processes involve addition to the C=N bond, and provide further evidence for the similarity between CO and isocyanide l i g a n d ~5 .4~ [Pt(diphos)(CNMe),I2

+

1x-

[ P t ( d i p h o s ) ( C N M e ) X ] + w [Pt(diphos)(CNMe)(CONHMe)]+ (x = I ) N, (x = i ) k

1

[Pt(diphos)(CNMe)(CN,Me)]

+

[Pt(diphos)(CN Me)C(OR)]

+

+ [Pt(diphos)C(OR)=NMe,]

+ [Pt(diphos)(CN,Me),]

Scheme 24

Silicon, germanium, and tin donor. ligands. Following a preliminary details have appeared of the preparation of the complexes (NEt,)[ Pt(C0)Cl(SnCl,),] and (AsPh,)[Pt(C0)C1(ROH)(SnCl3),] (R = Me or Et). It was not established whether the solvent was co-ordinated to the Pt or Sn in the latter complexes. Their substitution reactions with N, P, As, and Sb ligands were also in~estigated.~'~ An interesting paper describes the synthesis of the first compounds containing optically active Si and Ge atoms bonded to Pt, employing the reactions: cis-[PtCl,L,]

+ Me(1-CIoH,)PhSiH

-trans-[PtClL,{SiMe( l-C,,H,)Ph}] Et N

(L = PMe,Ph) trans-[PtHCIL,]

Et N + Et(1- C,,H,)PhGeH C,H,rrans-[PtClL,(GeEt( l-C,,H,)Ph}]

These reactions proceed predominantly with retention of configuration at the Si and Ge centres.3s5 Oxidative addition of HSiC1,Me to [Pt(PPh,),] has provided the new Si-Pt complexes cis-[PtH(PPh,),(SiCI,Me)], cis-[Pt(PPh,),(SiCl,Me),], and (92) which is suggested to be a dimer involving both Pto and Pt" atoms.356 Ph,P

\

/

PhJP

Pt

/

\

SiMeC1,

\

/

SiMeC1,

Pt

/

PPh,

\

PPh,

355

P. M. Treichel and W. J. Knebel, J . Amer. Chem. Soc.. 1971,93, 5424. C. Eaborn, P. N. Kapoor, D. J. Tune, C. L. Turpin, and D. R. M. Walton, J . Organometalfic

356

Chem.. 1972,34, 153. W. Fink and A. Wenger, Helv. Chim. Acta, 1971, 54,2186.

3s4

2E

434


Platinum(m).-Unlike the photochemistry of [PtXJ2- (X = Br or I) in which only photoaquation is observed,357 flash photoiysis of [PtC1J2- in its C1 -+ Pt charge-transfer band has been shown to result also in photoreduction. The unusual Pt"' complex [PtCl,]- k produced via the mechanism:358

-

[PtClJ-L

[PtClJ-

+ c1.

[PtcI,]Z-

[PtClJ

+ c1-

Platinum(rv).-Group VII Donors. Simple syntheses of hexafluoro-complexes of some noble metals have been reported, including K,[PtF,]. The method involved the melt reaction between KHF, and K,[PtX,] (X = C1, Br, or I), which has the advantage of not requiring corrosive reagents such as fluorine or BF3.116 The stepwise stability constants K, have been measured for the ( n = 4. 5, or 6) formed in bromoaquo-complexes [PtBr,- ,(H20)7 the aquation of [PtBr,]Z-.359 K and K, values are new, while the K, value indicates that an earlier determination is a factor of 10 An investigation of the room temperature reaction between H,[PtCI,] and DMF in the presence of HC1 has shown that acid decarbonylation of the solvent occurs, leading to [(DMAH)H][PtCl,] (DMA = d i m e t h ~ l a r n i n e ) . ' ~ ~ Group V l Donors. 1.r. spectroscopy has provided the first direct evidence for the existence of PtOH groups on the surface of metallic Pt. Bands at 3497 cm- ' were observed when oxygen reacts with hydrogen-covered Pt, and the alternative reaction of water with reduced Pt oxide produced a v(0H) at 3544 cm-'. These frequencies are in the region expected for Ptlv-hydroxy complexes.361 The treatment of PtCl, with quinazoline-2,4-dithione [LH (5 l)] has yielded the red-brown [PtCl,L,]. Its i.r. spectrum supports bidentate co-ordination of the ligand through both N and S , donors.254Similar spectral studies of the dimethylamino-ethanet hiolato Complex, [PtL2(H20),]C12, also indicate bidentate bonding. Comparison of the M-S force constants for a range of such the stability order Pt'" > Rh"' > Co" > Ni". compounds Group V Donors. Nitrogen donor ligands. Interesting molecular nitrogen complexes of proposed compositions K2[Pt(OH)4(N02)4(NH3)Z(N2)],2H20 and K2[Pt(C10,),(N0,),(NH,),(N2)],2KC104 have been isolated from the reactions of (NH,),SO, and NH4C104, respectively, with K,[Pt(NO,),]. These diamagnetic complexes decomposed in most solvents, liberating nitrogen gas which was determined quantitatively. The presence of linear Pt-N=N-Pt groups was confirmed by the presence of strong Raman bands at 2034 or

"' V. Balzani, F. Mangrin, and L. Moggi, Inorg. Chem., 1967,6, 354. 35B 359

360

"'

R. C. Wright and G . S. Laurence,J.C.S. Chem. Comm., 1972, 132. L. I. Elding and L. Gustafson, Znorg. Chim. Actu, 1971,5, 643. N . M. Nikolaeva and E. D. Pastukhova, Rum. J . Inorg. Chem., 1967,12,650. B. A. Morrow and P. Ramamurthy, Cunud. J . Chem., 1971,49,3409.

The Noble Metals

435

’,

which were absent in the i.r. spectra.362It is interesting that similar reactions do not occur with the Pd analogues.363A series of substituted propane-1,3-diamine (64) compounds of the type trans-[PtCl,(OH),L], trans-[ PtCl,(NH,),L]Cl,, and [PtLCl,] has been prepared.286Other new complexes reported are the series of electron-exchange type species [PtX,L,][PtX,L,] (X = C1, Br, I, or NO,: L = NH, or $en). Qualitative observations suggest that the strength of the cation-anion bonds increases in the order C1 < Br c A study of the photochemistry of tvan~-[PtBr,(NH,),]~+ has shown that photoaquation is the only reaction occurring. However, the observation of transient Br; in the flash photolysis, together with the formation of HCHO when methanol is solvent, suggests that the [PtBr(H,O)(NH,),I3 +.product is formed not only by simple photoaquation but also via the ion-pair mechanism :3 tran~-[PtBr,(NH,),]~’, Br- + H,O hv [PtBr(NH,),]’+ + Br; + €3 + OH2065 cm-

[PtBr(NH3),J3+ + H,O

H

+ CH,OH

-

H,

-

[PtBr(H20)(NH3),l3+

+ *CH,OH ~

H C H O

Similar photochemical investigations of [Pt(N02)(NH2)(NH3)4]2+ indicated that both photoisomerization to [Pt(ONO)(NH,)(NH,),12+ ( @ 2 5 4 = 0.1 1, @, = 0.29) and photoaquation of the NO, group occurred, together with some redox behaviour. The corresponding photochemical and thermal behaviour of the nitrito-isomer [Pt(ONO)(NH,)(NH3)4]2+ was also shown to involve other reactions as well as linkage isomerism.3b’ This resuli w n trasts with previous findings suggesting only linkage isomerism for this complex.366 The ‘H n.m.r. spectrum (220 MHz) of N-deuteriated [Pt(en),I4+ shows small chemical shift differences which were attributed to incomplete conformational averaging. The possibility that these differences may arise from inherent magnetic non-equivalence was excluded on the basis of observed differences in Pt-H coupling constants.367 Comparison of the aqueous spectrum of 2+

c1 (93) 362

363 364

363 366 361

V. M. Volkov and L. S. Volkova, Russ. J. Znorg. Chem., 1971,16, 1382. V. M. Volkov and A. I. Korosteleva, Russ. J . Inorg. Chem., 1971, 16, 1384. P. D. Fleischauer and A. W. Adamson, Inorg. Chim. Acta, 1972,6, 323. N. Sabbatini, L. Moggi, and G. Varani, Znorg. Chim. Acta, 1971,5,469. F. Basolo and G. S. Hammaker, Znorg. Chem., 1962, 1, 1. L. H. Novak and J. K. Beattie, Inorg. Chem., 1971, 10, 2326.

436


Table 8 X-Ray datafor platinum compounds Comments Ref R a 0.015 Determined with improved accuracy. Powder pattern only. h Isostructural with a-PtI, and PtBr,. Therefore assumed to have a [PtC1,,,C12], structure. Shows previous assignment of tetrahedral Sn1,-type structure incorrect. 0.099 rrans square-planar structure, with NO, groups co-ordinating through N. d 0.042 Roughly tetrahedral co-ordination about Pt'. e 0.066 Planar structure with 0-0 distance of 1.505 A. I

cis-[ PtCl,(CNEt)(PEt 2 Ph)] cis-[PtCl,(CNPh)2]

f 0.062 Square planar. Pt-C distances 0.046 indicate that isonitrile is a stronger R acceptor than carbene, but weaker than CO. trans influence of isonitrile is comparable to CO. Cluster contains square-planar g Pt. Contains only terminal CO groups. h Preliminary data. Square-planar co-ordination. Bond lengths suggest extensive delocalization in cyanoacetylido-group. trans square-planar structure i with bidentate thiol. Pt-As distance (2.354A) indicated (d4)a-bonding. j 0.042 Distorted from planar towards approximate tetrahedral structure. k 0.059 Distorted square plane. Shown to be a complex of fluorodithioformic acid. I 0.099 Approximate square antiprism of s atoms containing Pt" atoms in the two square faces. Involves a Pt-Pt bond (2.87 A), and two bridging and two terminal ligands.

The Noble Metals

Compound trans-[Pt(NH,),(N,C4H,),IC1,,2H,0

c~s-[P~,C~,(PP~,),(SE~)~]

[Pt(PPh,),MeISO,] (a) R. H.

43 7

R Comments Ref. 0.049 Square-planar structure m stabilized by H-bonds. 0.05 Dimer containing ethanethiolato n bridges. Each Pt is approx. square planar, but a dihedral angle of 130" between two co-ordination planes. (d-d)noverlap allowed in Pt,S, bridge. 0.092 Contains novel arrangement of o two square-planar Pt-bis(ethylene-1,2-dithiolene)units joined by a direct Pt-Pt bond (2.77 A). Square planar, with SO, P co-ordinated to the I.

B. Mais, P. G. Owston, and A. M. Wood, Acta Cryst., 1972,B28,393;(b) M. F. Pilbrow,

J. C. S. Chem. Comm., 1972,270;(c) R. Graziani, G: Bombieri, and E. Forsellini, Inorg. Nuclear Chem. Letters, 1972,8, 701;(d)V. G . Albano, P. L. Bellon, and M. Manassero, J. Organometallic Chem.,

1972,35,423;(e) ref. 303;(f)B. JovanoviC, L. ManojloviC-Muir, and K. W. Muir, J. Organometallic Chem., 1971,33,C75;B. JovanoviC and L. Manojlovik-Muir, J. C. S. Dalton, 1972,1176;(8) ref. 302; (h) W. H.Baddley, C. Panattoni, G. Bandoli, D. A. Clemente, and U. Belluco, J. Amer. Chem. SOC., 1971,93,5590;(i) J. P.Beale, L. F. Lindsay, S. E. Livingstone, and N. C. Stephenson, Inorg. Nuclear Chem. Letters, 1971, 7 , 851 ; C,H,SAsMe, = dimethyl-0-thionophenylarsine;(j] W. A. Spofford, E. L. Amma, and C. V.Senoff, Inorg. Chem., 1971,10,2309; S(p-ClC,H,), = 4,4'-dichlorodiphenylsulphide; (k) ref. 326;( I ) J. P. Fackler, J . Amer. Chem. SOC., 1972,94,1009; (m)J. W. Carmichael, N. Chan, A. W. Cordes, C. K. Fair, and D. A. Johnson, Inorg. Chem., 1972, 11, 1117;N,C,H, = Nmethylimidazole; (n) M. C. Hall, J. A. J. Jarvis, B. T. Kilbourn, and P. G. Owston, J. C. S. Dalton, 1972,1544;(0)rev. 282;(p) ref. 220.

(+)-[PtCl,(NH,),(en)]Cl, with that of its (+)-Co"' analogue of known configuration, has suggested the absolute configuration (93). The five observed optically active bands have been assigned to d - 4 and charge-transfer electron transitions.368 From a potentiometric titration study of the complexes [Pt(en)(pn),14 +, [Pt(en),(pn)14 +, [Pt(en),(NH ,I,]" +, and [Pt(en)(NH,),Cl] , it has been shown that the acid strength of the co-ordinated amines decreases in the order pn 1: en > NH,. Two different samples of the pentamine gave K values varying by a factor of ten, confirming their isomerism.369An i.r. spectral examination of [PtCl,L,]H20 and [Pt(OH),L,] (LH = 8-amino-7-hydroxy4-methylcoumarin), together with a range of other metal complexes of this ?). ligand. suggests a correlation between certain vibration bands [ e . g . vaC,,,,fNH v(M-N)] and the stability of the complexes.40 Phosphorus donor ligands. The yellow-green complexes cis-[PtCl,{ P(iOC,H,),},] and cis-[PtCl,{P(OEt),),] have been prepared by bubbling chlorine through chloroform solutions of their Pt"-dichloro analogues. +

369

0. N. Adrianova and T. N. Fedotova, Russ. J . Inorg. Chem., 1971,16,586. K. I. Gil'dengershel, S. I. Pechenyuk, A. I. Stetsenko, and V. F. Budanova, Russ. J. Znorg. Chem., 1971,16,1084.

[Pt(en)J4+, X-

?

C1, Br ?

r

Studied replacement of one X by H 2 0 . d This is the most strongly held of three halide ions. e Measured outer-sphere association constants. Bromide interacts with [Pt(en)J4+ less strongly than C1-. Values higher than an earlier estimation

Comments R elf: a Aspartate chelates are slightly more stable than corresponding glutamate chelates Studied replacement of one Br- by H,O. h Results show that thermodynamic cis effect is small. Order of increasing cis influence parallels trans influence order. c Studied replacement of one C1 by H,O.

3

%

2

2 3

2 . 0

2 3

x

(b

3

s

3

$.

(a) M. K. Singh and M. N. Srivastava, J . Inorg. Nuclear Chem., 1972,34,2067; (b)V. I. Dubinskii and E. A. Ranneva, Russ. J . Inorg. Chem., 1972,16, 1451; (c) Y.N. Kukushkin and K. M. Trusova, Russ. J . Inorg. Chem., 1971,16,750; (d) Y. N. Kukushkin, K. M. Trusova, V. N. Tolstousov, and V. V. Bardin, Russ. J . Inorg. Chem., 1972,16, 1330: (e) V. E. Mironov and L. A. Nikulina, Russ. J . Inorg. Chem., 1972,16, 1797: (f)C. J. Nyman and R. A. Plane, J . Amer. Chem. SOC.,1960,82,5781. 8-

[PtXJDMSO)] -

H20

C1, Br

potentiometric titration, and pH studies. poten tiomet ric

Method of Studv potent iomet ric tit ration

c1

Complex Pt'"L PtL,

potentiometric

Soluent H,O

Br

Aspartic acid Cilutamic acid

Ligand

Table 9 Stability constant data for platinum compounds

00

w P

The Noble Metals

439

Table 10 1.r. structural studies of platinum complexes Complex Other studies trans-[ PtX,py,] Also Pd truns-[PtX2(4-Mepy),] (X = C1 or I) ~ ~ u ~ s-[P~C~,(NX,CX,)~] (X = H or D) [Pt(tn),(NHd,]C12 [Pt(tnOH),]Cl, [Pt(tnCl),]Cl, [Pt(tnOH)(NH3),CI2]C1,

'H n.m.r.

[Pt(NO)XA,IX,

(X = C1, Br, HSO,, or NO,; A = NH,, MeNH,, PrNH,, or +en)

[Pt(MeCONHNH,),][PtCl,]

[Pt(MeCONHNH,),]Cl,

Cu, Cd

Results and Conclusions Assigned v(M.---X)and v(M-N) bands.

Ref: a

Performed a normal co-ordinate h analysis of vibrations of the PtNX,CX3 model. Calculated force constants. C Assigned v(0--H) in tnOH complex. 'H N.m.r. indicates chelate ring is in chair conformation with OH (or C1) axial. d Investigated influence of X on v(N0). Replacement of C1- or Br- by HSO, or NO, leads to an increase in v(NO), and in ease of hydrolysis. Suggest marked differences to Ru-NO complexes are due to fact that NO is a one-electron donor in Pt. e Data show that ligand is chelated O=C-Me Pt'

\

I

in bis complex, but is

H,N-NH unidentate in tetrakis compound. f Ni, Cu, Pd" Low-frequency i.r. shows that mta ligand co-ordinates only through NH, group. Square plane about Pt is completed by co-ordinated X. Assigned all bands. Performed a g Ni, Pd normal co-ordinate analysis. v(M-N) decreases in order Pt > Pd > Ni, suggesting same trend for strength of co-ordinate bonds. Thermogravi- Shows absence of co-ordinated h water, and presence of bound metric OH. Also Pt-OH band assigned. Thus confirmed structure as hexahydroxide rather than PtO,,xH,O. i Assigned v(Pt-Pt) and v(Pt-Sn) stretching bands of cluster as part of a normal co-ordinate analysis. Force constant for Pt-Pt is somewhat


440

Table 10-continued Complex

Other studies

tranS-[PtM,(PY),l trans-[ PtM2(3-Mepy),] trans-[ PtM2(4-Mepy),] [M = Mn(CO),, Co(CO),, CPMo(CO),]

Pd

Results and Conclusions Re$ lower than expected for normal single bond. Obtained stretching frequencies j for Pt-M bonds. These are stronger than corresponding Pd-M bonds.

Pfeffer, P. Braunstein, and J. Dehand, Inorg. Nuclear Chern. Lerrers, 1972, 8, 497; (6) Y. Y. Kharitonov and I. K. Kireeva, Russ. J . Inorg. Chem.. 1971,16, 733: (c) T. G. Appleton and J. R. Hall, Inorg. Chem., 1972, 11, 117; tn = H,NCH,CH,CH,NH,: tnX = H,NCH,CHXCH,NH,; (d)A. I. Stetsenko, N. V. Ivannikova, and V. M. Kiseleva, Russ. J . Inorg. Chem., 1971, 16, 865; (e) Y. Y. Kharitonov and R. I. Machkhoshvili, Russ. J . Inorg. Chem., 1971, 16. 847; (.J) M. Ikram and D. B. Powell, Spectrochim. Actn, 1971, 27A, 1845; mta = 2-methylthioaniline; (9) A. Bigotto, V . Galasso, and G. DeAlti, Spectrochim. A c t 4 1971,27A, 1659; GM = glyoximate; (h) B. N. Ivanov-Emin, L. D. Borzova, N. U. Venskovskii, B. E. Zaitsev, and V. I. Portil'ya, Russ. J . Inorg. Chem., 1971, 16, 723: (i)A.Perzis,T. C. Strekas, and T. G. Spiro, Inorg. Chem., 1971,10,2617; C,H,, = 1,5-cyclo-octadiene; (j)P. Braunstein and J. Dehand, J . C. S. Chem. Comm.. 1972, 164.

(a) M.

These compounds in turn reacted with thiourea (tu) to yield [PtCl,{P(i-OC,H7),0H}(P(i-OC,H7)(OH),)(tu)]C1 and [PtC1,(P(OEt),O)(tu),]Cl. respectively, which suggests370 that P(OEt), has a stronger trans effect than P(i-OC3H7), when attached to Pt". In contrast to the thiourea reaction, treatment of the [PtCl,(P(OR),J,] species with excess P(OR), results in reduction and the formation of [Pt(P(OR),}4]2+ (R = Et or i-C,H,). Since Grinberg has suggested a correlation between trans influence and reducing ability, the extended trans effect order P(OEt), > P(i-OC,H,), > t u is indicated.371 7 Silver Silver(~).-Group VII Donors. A mass spectral investigation of AgCl indicated that the species Ag2+,Ag+, AgCl+, Agl. Ag,CI+, Agi, Ag,Cl+. Ag,Cll, and Ag,Cl,' are formed during electron-impact ionization. The vapour was believed to consist of AgCl and Ag3Cl, molecules.372 Group VVI Donors. Oxygefi donor ligands. From the observed diamagnetism of silver picrate it has been concluded that it contains tetrahedral Ag' ions.373 1.r. spectral studies of solutions of AgNO, or AgCIO, in DMSO have suggested the presence of the species [Ag(DMSO),]+. Since the v(S=O) band shifted to lower frequency while v(C-S) increased, co-ordination of DMSO via an 0 atom is indicated.374The complex [Ag(Te0,),13- has been reported to be present in aqueous solutions of Ag2Te0, at pH 8-12. This is of some interest

370 37'

2'3 373 374

A. D. Troitskaya and 2.I . Shmakova. Russ. J . Inorg. Chem., 1971, Id, 590. A. D. Troitskaya and Z . 1. Shmakova. Russ. J . Inorg. Chem., 1971,16,87?.

P . Graber and K. G. Weil. Ber. Bunsengesellschafi Phys. Chem., 1972,76, 410. J. P. Agrawal, IndianJ. Chem.. 1971, 9, 585. R . C. Paul, P. Singh, and S. L. Chadha, Indian J . Chem., 1971,9, 1160.

The Noble Metals

44 I

in view of the absence of previous information concerning the complexation behaviour of the tellurite ion.375 Sulphur and selenium donor ligands. The reaction between AgNO, and the series of thiocarbazide derivatives RCONHNHC(S)NHNH, (R = Me, Ph, or C6H4N) has produced white diamagnetic solids for which the polymeric structures (94) are proposed. Support for these structures comes from their low solubility, and i.r. data suggesting terdentate co-ordination via the terminal N, the amido N, and the S atom. The Ag' ion attains its usual co-ordination

number of four.376Coloured complexes of the type [AgLiIClO, and [Ag,Li](ClO,), (L1= dithio-oxamide, NN'-dimethyldithio-oxamide, or "'-tetraethyldithio-oxamide; L2 = NN'-tetramethyldithio-oxamide or "'-hydroxyethyldithio-oxamide) have been prepared by treating Ag+ with HClO, and free ligand. Conductivity and i.r. data confirm that the ClO, groups are not co-ordinated in solution or in the solid state. In addition the co-ordination behaviour of the ligands was shown to depend on the degree of substitution, the tetrasubstituted ligands showing tetrahedral bidentate (S,S) bonding, repbrt has appeared of AgI-Ag" whereas the other ligands are ~ n i d e n t a t e . ~A' ~ 78 equilibria with the ligand NN-di-n-b~tyldithiocarbamate.~ A study of the reaction between AgNO, and the ligands (95) has led to a more thorough characterization of AgNO,,(C,H,N,Se), and the isolation of the new complex AgN03,(C6H4N2S).379

(95)

X

=

S or Se

Group V Donors. A general synthesis has been reported for cationic trialkyl phosphite complexes of a range of noble metals, including [Ag{P(OR),},] +

3"

376 377

37' 379

2F

M. C. Mehra and S. M. Kahn, Canad. J . Chem., 1972,W. 1788. N. K. Dutt and N. C. Chakder, Znorg. Chim. Acta, 1971,5, 536. G. C. Pellacani and T. Feltri, Inorg. Nuclear Chem. Letters, 1972,8, 325. T. J. Bergendahl and E. M. Bergendahl, Inorg. Chem., 1972, 11, 638. R. H. Hanson and C. E. Meloan, Inorg. Nuclear Chem. Letters, 1971, 7,461.


442

Salts of (R = Me or Et). The Ag complexes readily dissociate in [Ag(CN),] - have been isolated with several bulky quaternary ammonium cations using the double decomposition reaction : K[Ag(CN),]

HO + AmCl 2 Am[Ag(CN),] + KCI

Their solubilities in organic solvents were measured to determine their suitability in solvent-extraction procedures.380 Silver(II).-Interest in this oxidation state continues to grow, so much so that it should no longer be regarded as rare.

Group V I I Donors. The hitherto unknown BaLAgF,], Cd[AgF,], and HgCAgF,] have been prepared, and shown to be isostructural with tetragonal K[BrF,] from X-ray powder pattern data. These highly coloured compounds are paramagnetic (p = 1.9 BM) and obey the Curie-Weiss law.381 Diffuse reflectance and e.s.r. measurements of the series of complexes Ag[MF,] (M = Sn, Pb, Zr, or Hf) are consistent with an elongated tetragonally distorted [AgF6I4This is the first example of such geometry in a Ag'I-F complex, although similar distortion has been observed in systems with Ag" doped into suitable crystal lattices.383 Group V I Donors. The thio-oxinato-complex Ag(C,H,NS), (54; M = Ag) has been prepared, and its N and S co-ordination confirmed from i.r. data.274 Solution and powder e.s.r. studies of the compound isolated from the reaction between Ag' acetate and the NN-di-n-butyldiselenocarbamate anion confirm that it is a Ag" complex of structure (96).384A subsequent single-crystal e.s.r.

Bu /

Bu

N-C

\

/

Se

Ag

\

/

Se

\

Bu

study indicated significant deviation from the expected square-planar geometry about Ag towards C2,,.The low g value suggested strong n-covalence in the Ag-Se bond, while observation of the 77Sehyperfine interaction gave a measure of the covalency of the bond.385 Reaction of peroxydisulphuryl difluoride (S,O,F,) with metal salts has yielded a series of relatively rare oxyfluorosulphate complexes, including the black Ag,O(SO,F),. This complex, for 380

3RL

382

383 385

V. A. Petrova, V. P. Kurbatov, 0. A. Osipov, G. N. Shivrin, and G . V. Nemirov, Russ. J. Inorg. Chem., 1971, 16, 1352. V. R. H. Odenthal and R. Hoppe, Z . anorg. Chem., 1971,385,92. G. C. Allen, R. F. McMeeking, R. Hoppe, and B. Muller, J.C.S. Chem. Comm., 1972, 291. J. Sierro, J. Phys. Chem. Solids,1967, 28,417. V. R. Kirmse, B. Lorenz, W. Windsch, and E. Hoyer, 2. anorg. Chem., 1971,384, 160. V. R. Kirmse, W. Windsch, and E. Hoyer, 2. anorg. Chem., 1971,386,213.

The Noble Metals

443

Table 11 X-Ray data for silver compounds Compound

(NH4LCI2[Ag(S203)41 [Ag(NH:CH2C0;)]2(N03)2

R

Comments Ref: Ag is in a chloro-bridged planar a Ag2Cl: - structure, in which Ag has an approximate trigonal environment. 0.084 Approximate tetrahedral array of S b atoms around Ag. Dimer with Ag-Ag bond (2.88A) 0.1 1 C similar to metallic Ag. Silver atoms bridge centrosymmetric pairs of carboxy-groups forming dimers of glycine. Linear co-ordination of imidazole d N atoms about Ag. Each ligand co-ordinated to Ag via e N atom, and the 0 atom of the 2carboxy-group. Weak bonds to other 0 atoms complete tetragonally distorted octahedron about Ag. 0.070 Twinned crystals. Bipy and two unidentate NO3 groups form distorted square plane about Ag. (Inclusion of long bonds to NO, groups of neighbouring molecules gives distorted octahedral co-ordination). 0.117 Very distorted octahedron. Ag-Ag 9 bond significantly less than in metallic silver. Ag atoms bridged by two carboxylate ligands, and also co-ordinated to hydroxy 0 atoms of neighbours, and two water molecules. 0.050 Silver has distorted tetrahedral h co-ordination. Involves a unidentate tetrazole bonding via N(4), and two bridging tetrazoles linked to Ag via N(3) and N(4).

( a ) J. C. Bowles and D. Hall, Chem. Comm., 1971,1523: (b) F.Bigoli, A. Tiripicchio, and M. Tiripicchio Camellini, Actu Cryst., 1972,B28, 2079;( c ) J. K.M. Rao and M. A. Viswamitra, Actu Cryst., 1972,B28, 1484;(d) C. J. Antti and B. K. S. Lundberg, Actu Chem. Scund., 1971,25,1758;(e) ref. 389; (A ref. 388; (g) P. Coggon and A. T. McPhail, J . C. S. Chem. Comm.,1972,91: C1,H,,O3 = 3hydroxy-4-phenyl-2,2,3-trimethylcyclohexane-carboxylate; (h) R. L. Bodner and A. I. Popov, Inorg. Chem., 1972,11, 1410;C,,H,,N, = pentamethylenetetrazole.

C’oin p le.x

AgLi AgL

H2 0

H2O

75 $: EtOH

SCN-, I -

Diethyldithiocarbamate

R d

.s

‘s’

4\

Ag

f

Potentiometric, e.m.f.

Et,N-C

e

Solubility method Only one stability constant obtained indicating that L is bidentate. Unusual for Ag’.

L is bidentate, co-ordinating through hydroxyl and carboxylate 0 atoms.

pH titration

d

Complexes most stable in MeNO, and c sulpholan where Ag+ is weakly solvated, and no H-bonding between solvent and D M F is possible.

Potentiometric

h

a

More stable than corresponding DMSO and D M F complexes.

Comments Ligand co-ordinates through N. Also determined the four acid dissociation constants of L.

Potentiometric

and pH methods

Method of study Pot en t iome t ric

j

P.

(a) M. I. Gel’fman and N. A. Kustova, Russ. J . Inorg. Chem., 1971, 16. 1245; (b) D. C. Luehrs, J . Inorg. Nudear Chcm., 1972,34, 791; (c) D. C. Luehrs, ibid., p. 2701; (d) C. Tripathi and S. Paul, Indian J . Chem., 1972,10, 113; (e)V. A. P’yankov and 0. M . Brazovskaya, Russ. J . Inorg. C h e w 1971,16,815; (f)1. M . Bhatt and K. P. Soni, J . Indian Chem. SOC.,1972,49, 19.

AgL

(n = 1-4)

AgL,

o-Coumaric acid

Dimethylformamide (DMF)

H 2 0 , MeOH MeCN MeNO, Acetone and others MeNO,, MeOH, acetone, sulpholan, bu tan-2-01

AgL AgL2 AgL, AgL,

Ag( L-H 1

Hexamethylphosphoramide

H2O

II

s olvrt1 t

8-Azaguanine 0

Table 12 Stability constant data for silver compounds

Ligand

$

2

P

3

2 z.g.

$

%

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