COUNTERION INFLUENCE UPON THE BASIC DEHYDROBROMINATION REACTION IN FUNCTIONAL MICELLES

The basic dehydrobromination reaction of 2-(p-nitrophenyl)ethyl bromide has been studied in aqueous micelles of N-hexadecyl-N,N-dimethyl-N-(2-hydroxyethyl)ammonium salts (CDHAX; X = Cl, Br, NO3) in the presence and absence of univalent salts NaX. The added salts inhibit the reaction in hydroxyfunctional micelles CDHAX, and the anion order is similar to that for reaction in micelles of nonfunctional N-hexadecyl-N,N,N-trimethylammonium ion surfactants (CTAX). The reaction kinetics only in the absence of added salts can be described quantitatively in terms of ion-exchange and acid-base equilibria and the micellar effects of the cationic micelle upon the bimolecular reaction.