Kinetics of the oxidation of ethylbenzene by cobaltic acetate in acetic acid

Abstract

Under nitrogen and in the absence of strong acid, the reduction of cobaltic acetate by oxidation of ethylbenzene in acetic acid obeys kinetics that can be explained by assuming that cobalt are associated in the dinuclear species Co^III–Co^III and Co^III–Co^II, only the former being active for oxidation. In the presence of trichloroacetic acid, similar kinetics are observed except that no inactivation of Co^III by Co^II apparently takes place. In both cases, the experimental data are consistent with a mechanism whereby ethylbenzene is attacked by the cobaltic species to yield reversibly a benzylic radical. This scheme is further confirmed by the kinetics of oxygen uptake determined when the reaction is carried out in air.