A Comparative Analysis of Pseudophase Ion-Exchange (PIE) Model and Berezin Pseudophase (BPP) Model: Analysis of Kinetic Data for Ionic Micellar-mediated Semi-ionic Bimolecular Reaction

Abstract

Pseudo-first-order rate constants (kobs) for the reaction of N-benzylphthalimide (NBPT) with HO − have been determined at 2.0 × 10 −4 M NBPT, 1.0 × 10 −3 and 2.0 × 10 −3 M NaOH as well as varying concentrations of cetyltrimethylammonium bromide ([CTABr]T = 0.0-1.7 × 10 −1 M). The effects of [CTABr]T – CMC (with CMC representing the critical micelle concentration of CTABr) on kobs have been analyzed in terms of Berezin’s pseudophase (BPP) model and pseudophase ion-exchange (PIE) model. Although both models give the best observed data fit with least-squares values not significantly different from each other, the calculated values of KS from BPP model appear to be more reliable compared to those from PIE model because the values of KS from BPP model are similar to the corresponding KS values determined spectrophotometrically.