Kinetics and mechanism CF oxidation of DL-methionine by mangenese(III) in sulfuric acid medium

Abstract

The kinetics of oxidation of DL-methionine by manganesei(III) have been studied at 30°C in aqueous sulfuric acid medium. The reaction is first order each in managanese (III) and methionine. A suitable mechanism is proposed which leads to the rarte law. $$ - \frac{{d[Mn(III)]}}{{dt}} = \frac{{k_l [H^ + ][Mn(III)][Met]}}{{[H^ + ] + K_h }}$$ The oxidation of methione, a sulfur containing, optically active essential amino acid, has been studied from the mechanistic point of view only by a few oxidants like iodine [1, 2], chloramine-B [3], bromamine-B [4], chromium(VI) [5, 6], cerium(IV) [7] vanadium(V) [7] and hexacyanoferrate(III) (Os(VIII) catalyzed and uncatalyzed) [8, 9]. The present kinetic study on the oxidation of methionine by manganese (III) has been under-taken in aqueous sulfuric acid medium, since the reaction is very fast in aqueous perchloric acid medium.