Kinetic studies of oxidation–reduction of cobalt–ethylenediaminetetra-acetic acid complexes. Part IV. The reduction of ethylenediaminetetra-acetatocobaltate(III) and related complexes by chromous ion

Abstract

The nature of the chromium(III) products in the reduction of various polycarboxylatocobalt(III) complexes by chromous ion in dilute perchloric acid solution has been studied and the approximate rates of these reactions found by a competition method. These reactions, of the inner-sphere type, appear to be similar in mechanism to the previously studied reductions of the same complexes by ferrous ion.In the reductions of ethylenediaminetetra-acetatocobaltate(III) and trioxalatocobaltate(III) in weakly acid solutions the chromium(III) product contains three carboxylato-groups. However, it is probable that not more than two carboxylato-groups are transferred in the reduction of the cobalt(III) complex.