HAMMETT EQUATION AND MICELLAR EFFECTS UPON DEACYLATION

Substituent effects upon second order rate constants of reaction of OH - with phenyl p-substituted benzoates at surfaces of micelles of cetyl trialkylammonium bromide (alkyl = Me, Et, Pr and Bu) and tetradecylqui nuclidinium bromide fit the Hammett equation. Values of p increase wit h increasing bulk of the surfactant head group and are considerably la rger than in water, corresponding to decreases in micellar surface pol arity. The effects of substitution of the propyl group into the phenyl and benzoyl groups show that substrate orientation at micellar surfac es plays no significant kinetic role.