Chapter 13. Transition-metal carbonyls and organometallic complexes

Abstract

THE pattern of this year's review has not been changed from that adopted last year. The task of the reviewers in selecting reference becomes, however more difficult from year to year as the volume of published work increases. We hope we have included most of the more striking advances but there is certainly much interesting work which we have had to omit through lack of space. The most notable increase in effort has been in the field of platinum metal chemistry, and this has undoubtedly been stimulated by the ability of many of these complexes to act as homogenous catalysts in organic reactions. Although, as predicted last year, several new complexes of molecular nitrogen have been prepared, the problem of the catalytic fixation of nitrogen under mild conditions remains unsolved.Among the topics which have been reviewed are: metal carbony1s;l kinetics and mechanism of substitution reactions of metal carbonyls;2 the activation of molecular iiitrogen;3 the chemistry of the rarer platinum metal^;^ metal-metal bonds in transition-metal compounds ;5 organometallic derivatives from metal carbonyls and acetylene compounds;6 catalysis by cobalt carbonyl~;~ and mass spectra of organometallic compounds.* Volume 4 of the 'Annual Surveys of Organoinetallic Chemistry' has appeared,g also a useful comprehensive text book.lO Carbonyls and Hydridocarbony1s.-(a) Mononuclear. The electronic spectra of several neutral and ionic metal hexacarbonyls in the vapour and solution states have been recorded at room temperature. Some of the solution spectra have also been recorded at 7 7 " ~. Calculated molecular orbitals have been used for the purpose of transition assignments and also for a discussion of