Oxidation of Aspirin by a New Oxidant Diperiodatoargentate(III) in Aqueous Alkaline Medium

The kinetics of oxidation of aspirin by diperiodatoargentate(III) (DPA) in alkaline medium at a constant ionic strength of 1.0 mol dm −3 has been studied spectrophotometrically. The reaction between DPA and aspirin in alkaline medium exhibits 1: 2 stoichiometry (aspirin: DPA). The reaction is of first order in [DPA] and has less than unit order in both [ASP] and [alkali]. However, the order in [ASP] and [alkali] changes from first order to zero order as the concentration changes from lower to higher concentration. A decrease in the dielectric constant of the medium increases the rate of the reaction. The effect of added products and ionic strength of the reaction medium have been investigated and a mechanism is proposed.