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The removal of PSa− from bulk aqueous phase to the pseudo‐micellar phase by halobenzoate counterion X is responsible for the monotonic increase in kobs (pseudo first‐order rate constants) with the increase in the values of [MX] where MX = sodium salts of 2‐, and 4‐halobenzoic acids. The values of ion exchange constants, KnormalXBr or RnormalXBr for X = 2‐ and 4‐halobenzoate ions in the presence of tetradecyltrimethylammonium bromide (TTABr) were calculated from the apparent catalytic rate constants, Xkcat which represent the catalytic effect of CFN. Larger values of KnormalXBr or RnormalXBr were observed for X = 4‐halobenzoate ions than that for X = 2‐halobenzoate ions due to isomeric factors. The values of KnormalXBr or RnormalXBr determined in the presence of TTABr were compared with previously determined KnormalXBr or RnormalXBr values in the presence of cetyltrimethylammonium bromide (CTABr). The values of KnormalXBr or RnormalXBr are nearly 8 ~ 9‐fold larger for 4‐IBz−, 4‐BrBz− and 4‐ClBz− compared to the respective values of X = 2‐IBz−, 2‐BrBz− and 2‐ClBz−. The values of KnormalXBr or RnormalXBr for X = 4‐FBz− is nearly 3‐fold larger than that for X = 2‐FBz−. The values of KnormalXBr or RnormalXBr for X = 2‐ and 4‐halobenzoates are significantly smaller in the presence of TTABr than these in the presence of CTABr nanoparticles.

The efficiency of counterion affinity towards ionic micelles is often described in terms of the degree of counterion binding (β ) to ionic micelles or the conventional ion-exchange constant ([Formula: see text]) or relative binding constant ([Formula: see text]) of X and Br counterions. This review describes the use of ionized phenyl salicylate ions, PSa, as a new probe to determine [Formula: see text] values using a semiempirical spectrophotometric method. The value of [Formula: see text] is found to be comparable to reported values obtained using different probes by the semiempirical kinetic method as well as different physical methods. Application of semiempirical methods for calculation of [Formula: see text] or [Formula: see text] values involves an inherent assumption that these values are independent of the physicochemical characteristics of the probe molecule.

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