The influence of amphiphilic compounds on ionic organic reactions in aqueous solution

The effects of a cationic amphiphilic compound on the rates of a proton- and an hydroxyl ion-catalysed reaction have been investigated. Even at very low concentrations, such a compound retards the proton-catalysed hydrolysis of benzylidene aniline, and this effect increases with increasing concentration of the cationic compound. Conversely, the hydroxyl ion-catalysed hydrolysis of benzylidene acetophenone is accelerated at low concentrations of cationic compound; however, at higher cationic concentrations, the reaction is retarded. These effects are qualitatively explained by considering the effect of a cationic compound on the electrostatic forces between the reactant ions and on the steric shielding of the reaction site.