Are the Interfacial Basicities of Aqueous Cationic Micelles and Cationic Reverse Microemulsions Different by Orders of Magnitude?

Formation of 5-hexadecyl-7-methylindazole (16-Ind) from 2,6-dimethyl-4-hexadecylbenzenediazonium tetrafluoroborate (16-ArN 2 + ) bound to aqueous cationic micelles (prepared in aqueous buffers of pH 7.0) has been shown to originate from the remarkably high interfacial basicity of aqueous cationic micelles. The rationale behind our conclusion is that formation of indazole from o -methylarenediazonium salts has never been observed if the medium of the diazonium salts is not basic. On the same ground, the absence of any 16-Ind product from 16-ArN 2 + in cationic reverse microemulsions is consistent with the interfacial basicities of cationic reverse microemulsions being significantly lower than that of cationic micelles.