PROMOTED HYDROLYSIS OF SOME ORGANOPHOSPHATE ESTERS USING SUPPORTED [Cu(tmen)OH(OH2)]+
Abstract
In this study, tetramethylethylenedimine copper(II) complex (Cu(tmen)Cl2) was synthesized and natural clay smectite and synthetic Dowex-50WX8 resin containing Cu(tmen)(OH)(OH2)+ were prepared via ion exchange process in aqueous solution. Dowex- and smectite-supported Cu(tmen)(OH)(OH2)+ 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 mmol/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.
Keywords
Dowex-50WX8,Smectite,Tetramethylethylenedimine copper(II) complex,Diethyl-p-nitrophenyl phosphate
References
- Toy ADF, Walsh EN. Phosphorus Chemistry in Everyday Living. 2nd ed. Washington, DC, USA: American Chemical Society, 1987.
- Morales-Rojas H, Moss RA. Phosphorolytic reactivity of o-iodosylcarboxylates and related nucleophile. Chem Rev 2002; 102: 2497-2521.
- Quin LD. A Guide to Organophosphorus Chemistry. New York, NY, USA: Wiley, 2000.
- Yang YC, Baker JA, Ward JR. Decontamination of chemical warfare agents. Chem Rev 1992; 92: 1729-1743.
- Munro NB, Ambrose KR, Watson AP. Toxicity of the organophosphate chemical warfare agents GA, GB, and VX-implications for public protection. Environ Health Perspect 1994;102: 18-38.
- Gallo MA, Lawryk NJ. Organic Phosphorus Pesticides. The Handbook of Pesticide Toxicology. San Diego, CA, USA: Academic Press, 1991.
- Mersal GAM, Ibrahim MM. Solution studies of tris(2-benzylaminoethyl)amine complexes of zinc(II) and copper(II): The catalytic hydrolysis of toxic organophosphate. Cr Chim 2012; 15: 336-345.
- Tafesse F. Hydrolysis of nerve agent simulants by synergistic effects of tetraminecobalt(III) and microemulsions. Inorg Chim Acta 1998; 269: 287-291.
- Scrimin P, Ghirlanda G, Tecilla P, Moss RA. Comparative reactivities of phosphate ester cleavages by metallomicelles. Langmuir 1996; 12: 6235-6241.
- Hafiz, AA. Metallosurfactants of Cu(II) and Fe(III) complexes as catalysts for the destruction of paraoxon. J Surfactants Deterg 2005; 8: 359-363. Hay RW, Govan N. The [CoN4(OH)(OH2)]2+ (N4 = trpn, cyclen and tren) promoted hydrolysis of the phosphotriester 2,4-dinitrophenyl diethyl phosphate. Transit Metal Chem 1998; 23: 721-725.