The oxidation of methionine by oxidants such as imidazolium chlorochromate (ICC) and benzimidazolium chlorochromate (BCC) in aqueous perchlorate medium has been studied spectrophotometrically over the range 3.00≤103 [methionine] ≤ 6.00, 0.01 ≤ [H+] ≤ 0.03 mol dm-3 and 20 oC ≤ T≤ 40 oC. The rate of reaction was found to increase with the increase of total concentration of methionine and total concentration of H+. The reaction was found to exhibit first order dependence in [methionine], [H+] and the oxidants [ICC] and [BCC]. The ΔH≠ (kJ/mol) and ΔS≠ (JK-1mol-1) for the electron transfer reaction were found to be 12.5 and -154.1 in case of ICC and 17.53 and -136.9 in case of BCC respectively. The product of the reaction was found to be methionine sulphoxide. The negative values of ΔS≠ support ordered transition state for both the electron transfer reactions due to ICC and BCC.
Imidazolium chlorochromate, Benzimidazolium chlorochromate, Methionine, Electron transfer