Micellar Effects on Diazo-coupling Reaction

Abstract

Effects of cationic, anionic, and nonionic surfactants on the coupling rate have been investigated kinetically. It has been found that micellar effects are affected by the formal charge of both reactants, i. e., diazonium ion and substrate. For example, the reaction of m-chlorobenzenediazonium ion with N, N-bis(2-hydroxyethyl)aniline was considerably accelerated by anionic surfactants such as sodium dodecyl sulfate, sodium alkylbenzenesulfonate, and sodium laurate. In the reaction of diazoniobenzene-4-sulfonic acid with it, however, no pronounced micellar effects have been observed. Whereas the reaction of diazoniobenzene-2, 5-disulfonic acid, bearing net formal charge of with it, was accelerated by cationic surfactant.
The influence of formal charge of reactant on micellar effect has also been investigated by using 1-naphthylamine-4-sulfonic acid as a substrate. The results obtained have been interpreted in terms of electrostatic interaction between micelles and reactants.