Reactions of co-ordinated ligands. Part V. The mechanisms of the hydrolyses, ester-exchange reactions, deuteriations, and racemisation of the copper(II), zinc(II), magnesium(II), and palladium(II) complexes of N-(alkoxycarbonylalkyl)salicylideneimines

Abstract

It is suggested that neutral complexes, in which one or both ester groups are co-ordinated to the metal, are involved in the ester-exchange reactions, hydrolyses, deuteriations, and racemisations which have been reported for the copper(II) and other divalent metal complexes of N-(alkoxycarbonylalkyl)salicylideneimines. This suggestion is supported by the failure of the palladium(II) complexes to undergo the ester-exchange reactions and deuteriations.

The hydrolysis and ester-exchange reactions of carboxylic esters which have a nitrogen atom in the β- or γ-position, and which can function as bidentate chelating agents by using both the nitrogen atom and the ester group, are catalysed by metal complexes which are able to add the esters reversibly.