Catalytic Carrier Effect of Reversed Micelles in Anhydrous and Hydrous Systems

Abstract

The carrier effect of reversed micelles of sodium or barium 1, 2-bis(2-ethylhexyloxycarbony1)-1-ethanesulfonates (NaOT or BaOT) and didodecyldimethylammonium bromide (DDAB) was studied on aminolysis of p-nitrophenyl acetate (PNPA) by alkylamines and imidazole in anhy-drous apolar solvents. The carrier effect which can be estimated from the difference between the rate constant in micellar solution and that in pure solvent was much marked (Tables 1, 2), The effect by DDAB micelle was higher than by NaOT or BaOT (Table 2). This can be elucidated by higher interaction of alkylamines and imidazole with DDAB than NaOT or BaOT. However, no correlation between the carrier effect and the magnitude of interaction was observed in the reaction systems of primary amines/NaOT and hexylarnine/NaOT or Ba0T.The carrier effect for aminolysis of PNPA by propylamine or histamine and for hydrolysis of PNPA by imidazole was also examined as a function of concentration of water solubilized by NaOT in cyclohexane (Fig. 6). The effect at higher concentration of water was elucidated in relation with the formation of microemulsion.