Optically active co-ordination compounds. Part XXXI. Stereoselective autoxidations of dimeric vanadium(IV) tartrate complexes

Abstract

The varying rates and products of uptake of dioxygen by solutions of vanadium(IV) tartrate complexes have been studied, using manometry arid electronic spectra, as a function of the particular isomeric (i.e.D, L or meso) of tartaric acid which is present. Effects of pH are described.

In the systems containing D(or L) or a racemic mixture of D- and L-tartaric acid a deep orange complex is formed in the range pH 2·5–6·5, but not in that containing meso-tartaric acid. Circular dichroism and Raman spectra of the orange complex have been measured and a Job's plot made on the system in an attempt to determine the stoicheiometry. A possible structure for this complex is discussed.