This article was published online on 28 April 2014. Errors were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 15 May 2014.
Kinetics and Mechanism of Oxidation of l-Histidine by Permanganate Ions in Sulfuric Acid Medium
Article first published online: 28 APR 2014
© 2014 Wiley Periodicals, Inc.
International Journal of Chemical Kinetics
Volume 46, Issue 7, pages 370–381, July 2014
How to Cite
FAWZY, A., ASHOUR, S. S. and MUSLEH, M. A. (2014), Kinetics and Mechanism of Oxidation of l-Histidine by Permanganate Ions in Sulfuric Acid Medium. Int. J. Chem. Kinet., 46: 370–381. doi: 10.1002/kin.20857
- Issue published online: 28 APR 2014
- Article first published online: 28 APR 2014
- Manuscript Accepted: 3 APR 2014
- Manuscript Revised: 22 FEB 2014
- Manuscript Received: 29 OCT 2013
The reaction kinetics for the oxidation of l-histidine by permanganate ions have been investigated spectrophotometrically in sulfuric acid medium at constant ionic strength and temperature. The order with respect to permanganate ions was found to be unity and second in acid concentration, whereas a fractional order is observed with respect to histidine. The reaction was observed to proceed through formation of a 1:1 intermediate complex between oxidant and substrate. The effect of the acid concentration suggests that the reaction is acid catalyzed. Increasing the ionic strength has no significant effect on the rate. The influence of temperature on the rate of reaction was studied. The presence of metal ion catalysts was found to accelerate the oxidation rate, and the order of effectiveness of the ions was Cu2+ > Ni2+ > Zn2+. The final oxidation products were identified as aldehyde (2-imidazole acetaldehyde), ammonium ion, manganese(II), and carbon dioxide. Based on the kinetic results, a plausible reaction mechanism is proposed. The activation parameters were determined and discussed with respect to a slow reaction step.