The alpha-effect in micelles: Nucleophilic substitution reaction of p-nitrophenyl acetate with N-phenylbenzohydroxamate ion

Pseudo-first-order rate constants have been determined for the nucleophilic substitution reactions of p-nitrophenyl acetate with p-chlorophenoxide (4-ClC6H4O-) and N-phenylbenzohydroxamate (C6H5CON(C6H5)O-) ions in phosphate buffer (pH 7.7) at 27 degrees C. The effect of cationic, (CTAB, TTAB, DTAB), anionic (SDS), and nonionic (Brij-35) surfactants has been studied. The kobs value increases upon addition of CTAB and TTAB. The effect of DTAB and other surfactants on the reaction is not very significant. The micellar catalysis and alpha-effect shown by hydroxamate ion have been explained. (c) 2005 Wiley Periodicals, Inc.