Deprotonation of 5-nitroindole and its 2-carboxylate ion in twin-tailed surfactants

Deprotonations of 5-nitroindole (1) and its 2-carboxylate ion (2) at high pH are increased by selfassemblies of didodecyldimethylammonium chloride and hydroxide (DDDACl and DDDAOH). The increased deprotonation can be accounted for quantitatively in terms of binding of OH– and the indicatiors to the colloidal self-assemblies. Basicity constants in the self-assemblies are similar to those in micelles of cetyltrimethylammonium chloride, bromide, and hydroxide (CTACl, CTABr, and CTAOH) and are slightly smaller than in water.