Transition Metal Complexes of Phosphorus, Arsenic and Antimony Ligands

436 Pages·1973·42.51 MB·English

by  C. A. McAuliffe (eds.)

TRANSITION MET AL COMPLEXES OF
PHOSPHORUS, ARSENIC AND
ANTIMONY LIGANDS
ASPECTS OF INORGANIC CHEMISTRY
General Editor: C. A. McAuliffe
Transition Metal Complexes
of Phosphorus, Arsenic and
Antimony Ligands
edited by
c. A. McAULIFFE
University of Manchester Institute of Science and Technology
Macmillan Education
© C. A. McAuliffe 1973
Softcover reprint ofthe hardcover 1st edition 1973 978-0-333-13628-7
All rights reserved. No part of this publication may be
reproduced or transmitted, in any form or by any means,
without permission
First published 1973 by
THE MACMILLAN PRESS LTD
London and Basingstoke
Associated companies in New York
Melboume Dublin Johannesburg and Madras
ISBN 978-1-349-81560-9 ISBN 978-1-349-81558-6 (eBook)
DOI 10.1007/978-1-349-81558-6
This volume is dedicated to
Frederick G. Mann, FR.S.,
to whom the subject owes so much
FOREWORD
by
Professor J. Chatt
University of Sussex
I am very grateful to the Editor for his invitation to write a short introduction to
this book, which is dedicated to Frederick G. Mann, F.R.S. Dr Mann was my Research
Supervisor and mentor from 1937 to 1939. He introduced me to the fascinating
organic-type chemistry of complex compounds containing tertiary phosphines, arsines
and stibines at a time when remarkably little was known about them.
A few organic phosphines and arsines had been prepared during the latter half of
the last century. The chemists who prepared them had investigated their reactions
with various metal salts in analogy with amines, and had reported the formation of
addition compounds. Some were salts, such as the platinichlorides obtained from
acid solution, and others were substances now known as coordination compounds.
The cis and trans isomers ofbis(triethylphosphine)dichloroplatinum(II) were isolated
in 1870 by Cahours and Gal, the yellow isomer being labelled oe and the white one ß.
With the advent in 1893 of Werner's theory of coordination the structures of complex
compounds and the nature of the isomerisation of the platinum(II) complexes
became understandable. Werner was able to assign the cis configuration to the brighter
yellow [PtCI2(NH3hl isomer and the trans to the paler yellow. By analogy all the
other platinum(II) isomers were assigned configurations according to their colours.
The colourless ß-[PtCIlPEt3hl, now known to be cis, was thought until1936 to
have a trans configuration. From the time of their discovery until about 1930 the
complex compounds of the tertiary phosphines, arsines and stibines received scant
investigation and the isomerie platinum(II) complexes, except for the ammines, were
given wrong configurations.
In the early part of this century many organo-arsenicals were found to have marked
therapeutic value, and others to have potential use as 'poison gases', vesicants or
sternutators, in war. Thus there was a great extension of organoarsenic chemistry and
by 1930 many more organoarsenicals were known than organic phosphorus, anti
mony and bismuth compounds added together. During the First World War the
Germans started to use shells containing organoarsenicals. Sampies were sent to
Professor W. J. Pope, a member of the Chemical Warfare Committee, who started an
investigation of the compounds. He had two assistants, E. E. Turner and later F. G.
Mann, both of whom eventually became Fellows of The Royal Society. In this way
organoarsenic work came to Cambridge.
When the war was over Turner emigrated to Sydney in Australia and there he
viii Foreward
continued his study of organoarsenicals. Mann remained in Cambridge, becoming
interested in the semi-polar double bond or coordinate link, whether it occurred in
complex compounds or in organic compounds. There was still some doubt about
the nature of the bond between the metal and ligand in complex compounds and the
parachor, introduced by Sugden in 1924, was then a new and respectable method of
determining bond type. It was thought to be an additive quantity, with each atom
and bond having adefinite parachor. Because its determination involved the
measurement of the surface tension of a substance it was applicable only to liquids
or easily meltable solids. By 1930 parachors of the common elements and of the
common bond types in organic compounds had been estimated. Mann wished to
apply the parachor to determine bond type in co ordination compounds and for
this purpose he needed readily fusible stable coordination compounds. Amongst
those he chose were the tertiary arsine and tertiary phosphine complexes of palladium
and mercury halides. His investigation served mainly to increase greatly the number
of such complexes and to show that the parachor was useless as a method of deter
mining bond type. However, on thermal decomposition some of the palladium com
pounds, [PdCI (AsR hJ, they lost trialkylarsine, so being converted into halogen
2 3
bridged complexes, [Pd CI AsR hJ, for which he developed a better and more
2 4 3
general synthetic method. Then, even the existence of halogen bridging was contro
versial, but the presence of such bridges was established by X-ray analysis and the
basis of a whole new and interesting chemistry was opened up. In about a dozen
papers in the 1930s, Mann and his coworkers described more new tertiary phosphine
and arsine complexes than had been prepared in the whole previous history of
complex chemistry.
A parallelline was developed in Copenhagen by K. A. Jensen, who prepared a
great number of simple tertiary phosphine, tertiary arsine and dialkylsulphide com
plexes of platinum and determined their dipole moments, showing that all the
isomers that were previously thought to be trans were cis, and vice versa. He also
showed that tertiary phosphines would stabilise unusual oxidation states by preparing
[NiBr3(PEt3)2]. In the meantime another line stemming from Pope in Cambridge
had slowly taken root in Australia. E. E. Turner handed on his techniques and
interests to G. J. Burrows of Sydney before he returned to England in 1921 and
Burrows turned to the study of arsine complexes. This interest was handed on to
F. P. J. Dwyer and through Dwyer to R. S. Nyholm. Nyholm emigrated to London
after the Se co nd World War, where he developed a very flourishing school of arsine
complex chemistry at University College, based mainly on the famous diarsine,
o-C6H4(AsMe~2' first prepared in Mann's laboratory in the late 1930s.
The early parachor work of F. G. Mann was done in collaboration with a young
student named Donald Purdie. He was killed in the Second World War in Malaya, but
not before he had prepared with Mann many series of complexes of various elements,
palladium, mercury, cadmium, zinc etc., with tertiary phosphines and arsines and
more than doubled the total number of such complexes known. I was brought into
the study of Mann's bridged complexes in 1937, and realised the enormous value of
tertiary phosphine and arsine ligands in bringing complex chemistry out of aqueous
Foreword ix
solution into organie solvents. In these ways the fusion of complex chemistry with
organic chemistry started to grow, and after the war this fusion caught the imagination
of young co ordination chemists everywhere. These old, but nevertheless newly re
discovered, complex compounds were found to be fine material for the study of the
behaviour of metal atoms in a non-aqueous environment. Out of this grew polymerisa
tion, hydrogenation and carbonylation catalysts, the development of alkyl and aryl
derivatives of the transition met als, the study of unusual stereochemistries and the
rnagnetic properties of asymmetrically coordinated transition metal ions, and much
of the vast new organometallic chemistry of the transition metals. This book is con
cerned with the chemistry that has led to these developments.
From the third quarter of the last century a small selection of tertiary phosphines
and their complexes had been known, but their chemistry had failed to stir the
imagination of chemists. I t was F. G. Mann, K. A. Jensen and G. J. Burrows (mainly
through his pupil Dwyer) who showed that they had a chemistry of great interest,
and it was they who handed on this interest to their disciples and followers, until
now we have the vast new knowledge that fills this volume.
J. CHATT
January 1973
PREFACE
There are few areas of inorganic chemistry in which research activity is as great as
in the study of transition metal complexes containing Group VB ligands. There is a
continuous increase in the number of papers which academic and industrial
laboratories produce in this field.
Apart from a review of the whole area by Booth in 1964, and a review of metal
complexes of diphosphines by Levason and McAuliffe in 1972, there have been no
other specific contributions to the review literature of this field. The authors of
this volume have thus reviewed transition metal complexes containing monodentate
phosphines, monodentate arsines and stibines, bidentate arsines, and multidentate
Group VB ligands. A section on the nature of the bond formed between transition
metals and Group VB ligands has also been included, since this topic has been the
subject of much discussion recently, and a reassessment of the nature of this
interaction seems timely. In general, complexes containing organometallic ligands
have been excluded, although carbonyls have been included. We have thus treated
the general area of coordination chemistry and not of organometallic chemistry.
The literature has been reviewed up to the end of June 1972.
As Editor I have attempted to produce uniformity in symbolism, nomenclature,
etc., and any shortcomings in this respect are directly attributable to me.
The aim of the book is to provide a reference text for workers in this field,
especially for workers new to the field who may fmd the literature already
bewilderingly large. It is also hoped that undergraduates may find this book useful.
In putting this volume together I have been valuably assisted at all stages by my
graduate student, William Levason. I wish also to thank my wife, Margaret, for her
assistance, encouragement and forbearance.
c. A. McAuLIFFE