PROMOTED HYDROLYSIS OF SOME ORGANOPHOSPHATE ESTERS USING SUPPORTED [Cu(tmen)OH(OH2)]+

In this study, tetramethylethylenedimine copper(II) complex (Cu(tmen)Cl 2 ) was synthesized and natural clay smectite and synthetic Dowex-50WX8 resin containing Cu(tmen)(OH)(OH 2 ) + were prepared via ion exchange process in aqueous solution. Dowex- and smectite-supported Cu(tmen)(OH)(OH 2 ) + were used as a promoter in the hydrolysis reactions of organophosphate compounds of diethyl- p -nitrophenyl phosphate and p -nitrophenyl diphenyl phosphate at different pH values. Scanning electron microscope attached with energy dispersive X-ray dedector and surface area analyzer were used for the characterization of the promoters. The efficiency of these promoters was evaluated in accordance with pseudo-first-order and Michaelis-Menten enzyme kinetic models. The amount of copper(II) complex in Dowex-supported promoter was higher than that of smectite-supported one (1.36 mmol/g and 0.88 mm ol/g, respectively) and the higher efficiency was obtained when Dowex-supported promoter was employed in all of the hydrolysis reactions. 222 and 114-fold increasing in pseudo-first-order rate constants compared to the reactions without promoter were observed for the hydrolysis of diethyl- p -nitrophenyl phosphate at pH 8.0 in the presence of Dowex-supported and smectite-supported promoters.