Kinetic Study of Oxidation of Valine by N-bromophthalimide in Presence of Iridium (III) Chloride as Homogenous Catalyst.

The mechanistic study of Ir(III) chloride catalyzed oxidation of Val has been studied by by N-bromophthalimide (NBP) in aqueous perchloric acid medium at 303 K. The reaction followed first order kinetics with respect to [NBP] and zero order kinetics with respect to [Val]. At lower concentration range of Ir(III) chloride, the reaction followed first order kinetics while tending to zero order at its higher concentration. A negative effect was observed for [H+] and [NHP] (phthalimide) whereas variation in [Hg(OAc)2] (mercuric acetate), [Cl-], ionic strength (I) and dielectric constant of the medium did not bring about any significant change on the rate of reaction. The rate constants observed at five different temperatures (298 K-318 K) were used to calculate the activation parameters. A plausible mechanism from the results of kinetic studies, reaction stoichiometry and product analysis has been proposed. [ABSTRACT FROM AUTHOR]