Kinetics and Mechanism of Rhodium(III) Catalyzed Oxidation of Ethylene Glycol by Acidified Sodium Periodate

Abstract

The kinetics of the Rh(III) catalyzed oxidation of ethylene glycol in an acidified solution of NaIO₄ in the presence of Hg(OAc)₂ as a scavenger, have been studied in the temperature range 30-45 ºC. The rate shows first order kinetics in [IO₄^–] and [Rh(III)]. The order of reaction with respect to the substrate is zero. Increase in [H⁺] and [Cl^–] show no effect. Negligible effects of mercuric acetate [Hg(OAc)₂] and ionic strength of the medium were observed. The effect of varying percentage of AcOH on the reaction rate was also observed. A suitable mechanism in conformity with the kinetic observations has been proposed. Various activation parameters were calculated from rate measurement and the rate law is derived on the basis of obtained data.