Reactions of betaine esters with hydroxide ion in reactive and unreactive counterion surfactant

Abstract

The reaction of hydroxide ion with methyl N-alkyl-N, N-dimethylglycinate(1) is catalysed by cationic micelles. The variation of the first-order constant, kψ, with the concentration of CTAC1 can be fitted to the pseudophase ion-exchange model, but this model fails when the counterion of the surfactant is OH-. The variations of kψ with counterion of CTAOH fit a kinetic model in which the distribution of the [OH-] between the aqueous and micellar pseudophase depends upon [OH-]. The value for the second-order rate constant in the micellar pseudophase predicted by both models is similar and it is smaller than the second-order rate constants in water. © 1987.