Binuclear solvent-dependent nature of some complexes relevant to molecular activation processes

Abstract

A brief account will be given on the ion-pair nature of very well known organometallic species, with regards to their role in the activation of organic substrates and small molecules. Two classes of co-ordination compounds will be discussed in this context; ‘acid–base’ transition metal–alkali cations and dinuclear copper(I) complexes. While the first type includes ion-pair species active in carbon dioxide fixation, the dinuclear copper(I) complexes may play a relevant role in carbon monoxide and dioxygen activation. The attention will be mainly focused on the following points: 1. the co-ordination of alkali cations by transition metal complexes, producing acid–base compounds, and their role in the interaction with carbon dioxide and carbon dioxide-like molecules; 2. some problems related to CO 2 activation, which seems to require ‘acid–base’ complexes; 3. the solvent-dependent synthesis of some dinuclear copper(I) complexes, in which both coppers(I) interact with the same substrate; 4. the problems associated with the high kinetic lability of some copper(I) complexes, to be used in molecular activation.