Kinetics of Cetyltrimethylammonium Bromide Catalysed Oxidation of Cyclopentanone by N-Bromophthalimide in Acidic Medium

Abstract

Abstract The effect of cationic micelles of cetyltrimethylammonium bromide (CTAB) and anionic micelles of sodium dodecyl sulphate (SDS) on the kinetics of oxidation of cyclopentanone by N-bromophthalimide (NBP) was studied iodometrically at 308 K. In addition to the kinetic experiments, conductivity measurements have also been done to obtain critical micelle concentration and other thermodynamic properties. The kinetic observations indicate fractional order and first order dependence with respect to [cyclopentanone] and [NBP] respectively. Cationic surfactant (CTAB) strongly catalyses the oxidation of Cyclopentanone in aqueous acetic acid medium. Typical kobs and [CTAB] profile were observed i. e. with the progressive increase in [CTAB], the reaction rate increased and at higher concentration of CTAB, constancy in kobs was observed. Anionic surfactant (sodium dodecylsulphate, SDS), mercuric acetate and phthalimide did not influence the reaction rate. The presence of inorganic salts (KCl, KBr) exhibits a severe hike in the reaction rate. The various activation parameters in the presence of CTAB have been also evaluated. A suitable mechanism consistent with the experimental findings has been proposed.