During recent years a high level of interest has been maintained in the kinetics and mechanisms of inorganic compounds in solution, and there has also been a notable upsurge of literature concerned with reaction mechanisms of organo­ transition metal compounds. The reviews of the primary literature previously provided by "Inorganic Reaction Mechanisms" (Royal Society of Chemistry) and "Reaction Mechanisms in Inorganic Chemistry" in "MTP International Re­ views of Science" (Butterworths) continue to be of considerable value to those concerned with mechanistic studies, and it is unfortunate they are no longer published. The objective of the present series is to provide a continuing critical review of literature dealing with mechanisms of inorganic and organometallic reactions in solution. The scope of potentially relevant work is very large, particularly in the field of organotransition metal chemistry, and papers for inclusion have been chosen that specifically probe mechanistic aspects, rather than those of a prep­ arative nature. This volume covers the literature published during the period July 1979 to December 1980 inclusive. Material is arranged basically by type of reaction and type of compound along generally accepted lines. Numerical data are usually reported in the units used by the original authors, though the units of some results have been converted in order to make comparisons.