Kinetic studies on the oxidation of cellulose and its model compounds by Mn(III)

Oxidation of cellulose and model compounds, including d-glucose, ethanol, 2,3-butanediol, and propanal in HClO4 solutions with Mn(III) as an oxidant found to be of first order with respect to Mn(III). A general rate expression was derived to explain the effects of the reactant concentrations and the acidity, with the roles played by Mn3+, MnOH2+, and their complexes being taken into account. Rate and equilibrium constants were determined under simplified experimental conditions. From the relative rate constants of oxidation for the model compounds, the reaction sites of glucose have been deduced. Cellulose was oxidized by electrogenerated Mn(III), which acts as an electron transfer mediator for the reaction. Its oxidation products show a new IR band at 1729 cm−1, which was assigned primarily to the ketone group produced during the oxidation.