An empirical approach to study the occurrence of ion exchange in the ionic micellar‐mediated semi‐ionic reactions: Kinetics of the rate of reaction of piperidine with ionized phenyl salicylate in the presence of cationic micelles

Pseudo‐first‐order rate constants ( k obs )—obtained for the cleavage of ionized phenyl salicylate (PS − ) at constant [NaOH], [MeCN], [CTAZ] T (total concentration of cetyltrimethylammonium chloride and bromide), [Pip] T (total concentration of piperidine), and varying concentrations of sodium cinnamate, acetate, and butanoate ([NaX])—follow the relationship: k obs = ( k 0 + θ K [NaX])/(1 + K [NaX]), where θ and K are empirical parameters. The values of θ are almost independent of [CTAZ] T , while K values decrease with the increase in [CTAZ] T within its range 0.006–0.020 M. The values of θ and K are explained in terms of pseudophase model of micelle coupled with an empirical relationship: K S = K S 0 /(1 + Ψ X/S [NaX]), where K S is the CTAZ micellar binding constant of PS − in the presence of NaX. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 288–294, 2001