Kinetics of oxidation of pinacol by aquocerium(IV) ions in aqueous perchlorate media
Abstract
The rapid oxidation of pinacol by CeIVaq in aqueous perchlorate media has been followed using stopped-flow spectrophotometry. The oscilloscope traces and the kinetics show that the oxidation is inner-sphere, involving Ce4+(CH3)2COH˙(CH3)2COHaq and Ce4+(CH3)2COH˙(CH3),CO–aq in the rate-determining steps. This is compared with the oxidation of alcohols by CeIVaq which involves analogous reactions and is similar to the inner-sphere oxidation of pinacol by MnIIIaq in aqueous perchlorate media. Energies and entropies of activation are compared.