Effects of Cationic Micelles on the Rate of Alkaline Hydrolysis of N-(2-methoxyphenyl)phthalimide

Abstract

Pseudo-first-order rate constants (kobs), obtained for the reaction of N-(2-methoxyphenyl)phthalimide (1) with HO− at a constant [NaOH] and varying concentrations of cetyltrimethylammonium bromide ([CTABr]T = 0.0–0.20 M), have been analyzed in terms of both pseudophase ion-exchange (PIE) model and Berezin's pseudophase (BPP) model. Although both models give the best observed data fit with least-squares values not significantly different from each other, the calculated values of KS from BPP model appear to be more reliable compared to those from PIE model. The nonlinear decrease of kobs with the increase of [NaBr] at the constant [NaOH] and [CTABr]T is explained in terms of pseudophase micellar model coupled with an empirical equation which could indirectly give the measure of the ion-exchange Br−/HO−.