Oxidation of Valine by N-Bromophthalimide in Presence of Chloro- Complex of Pd(II) as Homogenous Catalyst: A Kinetic and Mechanistic Study

Abstract

Kinetics of Pd(II) catalyzed oxidation of valine has been studied by N-bromophthalimide (NBP) in acidic me- dium at 303 K. The reaction follows first order kinetics with respect to (Pd(II)) while negative effect was observed for the variation of (H + ) on the rate of reaction. The reaction exhibits first order kinetics with respect to (NBP) at its lower con- centrations and tends towards zero order at its higher concentrations. Rate of reaction exhibits zero order and fractional order kinetics with respect to (valine) and (Cl - ) respectively. (Hg(OAc)2), (phthalimide), 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 utilized to calculate the activation parameters. A plausible mechanism has been proposed from the results of kinetic studies, reaction stoichiometry and product analysis.