Kinetics and Mechanism of Oxidation of Malic Acid by Morpholinium Fluorochromate in Aqueous Acetonitrile Medium

Abstract

Kinetics of oxidation of malic acid by morpholinium fluorochromate (MFC) in 50% (v/v) acetonitrile-water solvent mixture at 298 K in the presence of perchloric acid has been studied spectrophotometrically. The reaction is first order each with respect to malic acid, MFC and H + ion. Variation of ionic strength of the reaction medium or addition of acrylonitrile does not influence the reaction. However, the rate of reaction decreases significantly on addition of manganese sulphate. The reaction is favoured by lowering of solvent polarity. Activation parameters, E a , ∆H ‡ , ∆S ‡ and ∆G ‡ have been evaluated from the rate constant values measured at four different temperatures using Arrhenius and Eyring equations. Based on these findings, a suitable mechanism has been proposed.