Oxidation of Aliphatic Ketone Semicarbazones by Acid Bromate: A Kinetic and Mechanistic Study

Abstract

Kinetics of oxidation of semicarbazones by acid bromate in 25% aqueous acetic acid medium in the presence of perchloric acid has been investigated. The rate has first order dependence in [oxidant], fractional order in [substrate] and inverse fractional order in [H₃O⁺]. Addition of the reaction product, potassium bromide and variation of ionic strength of the medium have no effect on the rate. The rate increases with decrease in dielectric constant of the medium. Activation parameters have been evaluated from the Eyring plots. The stoichiometric studies reveal that the reactants react in 1 : 1 mole ratio via the formation of a complex. Mechanism consistent with the observed kinetics has been proposed and the related rate law derived.