Kinetics and Mechanism of oxidation of Miglitol by Bromamine –T (BAT) in HCl medium using RuCl3 as catalyst

Diwyab, R. Ramachandrappaa* an

Abstract

Kinetics and oxidation of Miglitol (MIG) by sodium -N- bromo - p- toluenesulphonamide (bromamine – T or BAT) in hydrochloric acid medium using RuCl3 as catalyst at 303K have been studied. The rate is first order in [BAT]o, fractional order in [MIG], fractional order in RuCl3, fractional order in [H+] and negative fractional order in [PTS]. Addition of NaCl and NaBr did not affect the rate of the reaction. Variation of ionic strength did not affect the rate of the reaction indicating that non – ionic species are involved in the rate limiting step. The dielectric effect is positive. Rate increased with increase in temperature from 293K to 323K. From the linear Arrhenius plot, activation parameters were computed. Addition of reaction mixture to aqueous acryl amide solution did not initiate polymerization, showing the absence of free radicals species. Oxidation products were identified. Protonated oxidant H2O+Br is the reactive species which reacts with the substrate. Based on kinetic results, reaction stoichiometry and oxidation products, a suitable mechanism have been proposed.