Kinetics of oxidation of sec-butanol and cyclohexanol by aquocerium(IV) ions in aqueous perchlorate media

Abstract

The oxidations of sec-butanol and cyclohexanol by Ce^IV in aqueous perchlorate media are inner-sphere reactions analogous to the oxidation of isopropanol by Ce^IV. The formation equilibrium constants for the Ce⁴⁺R₁R₂CHOH_aq complexes are of the same order as that for the Ce⁴⁺(CH₃)₂CHOH_aq complex. The oxidation involves two rate-determining steps, the first-order decomposition of Ce⁴⁺R₁R₂CHOH_aq and of Ce⁴⁺R₁R₂CHO^–_aq. Energies and entropies of activation for both reactions, and energies and entropies of formation of both complexes are calculated. These data are compared with similar data for isopropanol.