| Abstract
| - The hydrolysis reactions of 4-nitrophenyl diphenyl phosphate, 4-nitrophenyl di-4-tolyl phosphate, anddiethyl 4-nitrophenyl phosphate (paraoxon) have been studied in hexadecyltrimethylammonium anti-pyruvaldehyde 1-oximate (C16TAOx) buffer solutions prepared by 1:2 mixing of hexadecyltrimethylammonium hydroxide with anti-pyruvaldehyde 1-oxime, thus allowing the avoidance of counterion inhibitioneffects observed when using conventional cationic surfactants. The reactions are strongly accelerated bythe C16TAOx micelles, and the half-life for the persistent insecticide paraoxon is as low as 2 min at [C16TAOx] = 10-2 M. The data are discussed in terms of the pseudophase ion-exchange (PIE) model. However,this model is not sufficient to explain that the rate constants increase significantly when sodium oximateis added and that KCl and NaOAc salt effects exhibit S-shaped curves. Conductivity data suggest someminor variations in the degree of counterion association, β, but these variations are too small to accountfor the deviations from the PIE theory.
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