A Specialist Periodical Report Inorganic Reaction Mechanisms Volume 6 A Review of the Literature Published between July 1976 and December 1977 Senior Reporter A. McAuley, Department of Chemistry, University of Victoria, British Columbia, Canada Reporters J. Burgess, University of feicester R. D. Cannon, University of East Anglia J. L. Davidson, Heriof- Watf University, Edinburgh D. N. Hague, University ofKent A. G. Lappin, University of Glasgow W. E. Lindsell, Heriot- Watt University, Edinburgh P. Moore, University of Warwick G. Stedman, University College of Swansea The Chemical Society Burlington House, London WiV OBN British Library Cataloguing in Publication Data Inorganic reaction mechanisms.- (Chemical Society, Specialist periodical reports), Vol. 6 1. Chemistry, Inorganic 2. Chemical reactions I. McAuley, Alexander 11. Series 541’.39 QD151.2 73-642977 ISBN 0-85186-305-1 ISSN 0305-8255 Copyright 0 1979 The Chemical Society All Rights Reserved No part of this book may be reproduced or transmitted in any form or by any means - graphic, electronic, including photocopying, recording, taping or information storage and retrieval systems - without written permission from The Chemical Society Printed in Great Britain by Adlard & Son Ltd, Bartholomew Press, Dorking Fore word The format, coverage, and approach to this Sixth Volume dealing with Inorganic Reaction Mechanisms are similar to those for the previous volumes in this series. In view of the enormous scope for selection of materials, we have chosen (with an eye to cost and volume size) to concentrate on papers where kinetics and mechanisms in solution are the subjects of principal interest. Inevitably, in some papers where there is reference to mechanisms the treatment is somewhat more cursory with a consequent loss of subtlety. We hope, however, that any resultant oversimplification or misrepresentation is minimal. Review articles cited are those which should be accessible to the great majority of readers. Additional bibliography has been pro- vided in the organometallic sections. The period of coverage is from June 1976 to December 1977. The boundaries at both ends are somewhat vague since not all libraries have journal issues available at the same time. Care has been taken, however, to ensure that an overlap with Volume 5 is maintained in all areas. Where material has been derived from Chemical Abstracts rather than the original source a Chem. Abs. citation has been included in the reference quoted. References to the Russian literature derived from this source quote the page number of the original article whereas those giving the title of the English translation quote the page number of the translation. As in previous volumes, kinetic data are reported in the form and units used in the original articles (Ea,l og A or AH* and AS*). Some conversions have been made both in the text and in the tables where comparisons are required. The Reporters are grateful to many of their colleagues for helpful comments and for the critical reading of many of the chapters in this volume. A. MCAULEY Cont ents ~~ Part I Electron Transfer Processes Introduction 3 Chapter 1 Reactions Between Two Metal Complexes 5 By R. D. Cannon 1 General and Theoretical 5 Non-adiabaticity 5 Tunnelling 9 The Inverted Region 10 The Cross Relation 11 Other Theoretical Work 12 Related Areas 14 2 Intramolecular Electron Transfer 15 Precursor Complexes of Known Structure 15 Labile Dinuclear Intermediates- Direct Observation 16 Labile Dinuclear Intermediates- Indirect Evidence 18 Optical Electron Transfer 19 Mixed-valence Compounds 20 3 Intermolecular Electron Transfer 22 Inner- and Outer-sphere Mechanisms 22 Organic Bridging Ligands 24 Excited States 31 Non-complement a r y Reacti ons 32 Chapter 2 Metal Ion-Ligand Redox Reactions 69 By A. G. Lappin and A. McAuley 1 Iron(m) 69 2 CObalt(III) 78 3 Chromium(w) 82 4 Manganese(m) and Manganese(vni) 84 5 Copper(I1) and Copper (111) 85 vi Contents 6 Cerium(1v) 90 7 ThalliumOzI) 92 8 Nickel(1n) 94 9 Peroxodisulsphate 95 10 Peroxodiphosph a t e 97 11 Other Redox Reactions 98 Platinum(1v) 98 Octacyanometallate(v) Ions 98 Actinides 99 Gold (111) 100 Hexachloroirida te(rv) 100 Periodate and Iodate 101 Pal ladium(r1) Complexes 102 Vanadium(v) 102 Osmium(v1Ir) 102 Ruthenium(1v) 103 12 Metal-ion Reductions 103 13 Pulse Radiolysis 109 Chapter 3 Reactions involving Oxygen and Hydrogen Peroxide 115 By A. McAuley 1 Cobalt Complexes 115 2 Iron(u) Complexes 117 3 Other Metal Complexes 118 4 Hydrogen Peroxide Reactions 121 ___ Part /I Substitution and Related Reactions Chapter 1 Non-metallic Elements 129 By G. Stedman 1 Group 111 129 Boron 129 Tetrahedral Anions and Related Species 129 Boron-Hydrogen Compounds 130 Boron-Oxygen Compounds 130 Contents vii Aluminium 130 Gallium 131 Indium 131 Thallium 132 2 GroupIV 132 Carbon 132 Silicon 133 Germanium 137 Tin 137 Lead 138 3 Group V 139 Nitrogen 139 Phosphorus 142 Oxoanions and Related Species 142 Phosphorus-Oxygen-Nitrogen Compounds 144 Phosphazenes 144 Miscellaneous Compounds 145 Intramolecular Processes 146 Arsenic 147 Antimony 147 Bismuth 147 4 GroupVI 148 Sulphur 148 Selenium 149 Tellurium 149 5 GroupVII 150 Fluorine 150 Chlorine 150 Bromine 151 Iodine 151 Astatine 151 6 Group VIII 151 Xenon 151 Chapter 2 Inert Metal Complexes: Co-ordination Numbers Four and Five 153 By J. Burgess 1 Square-planar Complexes 153 Plat inum(I1) 155 Aquation, Solvolysis, and Anation 155 viii Contents Ligand Exchange 156 Entering Groups 156 Ring Closure 156 Ring Opening 157 Isomerization, Symmetrization, and Inversion 158 Effects of Non-leaving Ligands 160 Photochemistry 161 Reactions of Co-ordinated Ligands 161 Palladium(I1) 162 Solvolysis and Anation 162 Substitution 162 Isomerization and Inversion 163 Polynuclear Complexes 163 Reactions of Co-ordinated Ligands 164 Gold@) 164 Substitution 164 Isomerization 165 Redox and Substitution 165 Nickel(@ 165 Copper(d 166 2 Tetrahedral Complexes 167 sp-Block Metals 1 67 Transition Metals : Nickel(@ Complexes 168 Transition Metals : Oxoanions and Polynuclear Species 168 3 Five-co-ordinate Complexes 171 Chapter 3 Inert Metal Complexes: Co-ordination Number Six and Higher 1 74 By P. Moore 1 Introduction 174 2 Aquation: Cobalt(n1) Complexes 183 Unidentate Leaving Groups 183 Multidentate Leaving Groups 186 Effects of Non-leaving Ligands 187 [C~(en),xY]~C+o mplexes 187 [Co(LL),(L)X]n+ and [CO(LLL)(LL)X]~+C omplexes 189 [Co(LLLL) (L)X]n+ and [Co(LLLL)(LL)ln+ Complexes 189 Dioximato-complexes 193 Bridged Dicobalt Complexes 196 Solvent Variation 198 Catalysed Aquation 198 Photochemistry 1 99