Micellar Catalysis on Supernucleophile (HOO) Assisted Hydrolysis

In order to investigate the micellar catalysis on the hydrolytic cleavages of two important class of insecticides paraoxon (diethyl p-nitrophenyl phosphate) and parathion (diethyl p-nitrophenyl phosphorothioate) in presence of hydroperoxide ions, kinetic runs have been carried out at pH 9.0 at 37°C with and without cetyltrimethylammonium bromide (CTAB). Pseudo-first order rate constants are obtained at different surfactant concentrations. Activation parameters are determined with and without surfactant, their magnitudes are indicative of bimolecular mechanism. It is observed that a larger binding constant for parathion is not realized in to its enhanced hydrolysis reactivity.