Kinetic assessment of relative counterion penetration into cationic micelles: Effects of inert salt on the rate of piperidinolysis of phenyl salicylate in alkaline cationic micellar medium

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="metricconverter"> Pseudo-first order rate constants for piperidinolysis of ionized phenyl salicylate, obtained at 0.1 <i style="">M</i> piperidine, constant concentration of CTABr micelles and varying values of [NaOC₆H₄CO₂Na], follow the empirical relationship: <i>k</i>_obs = (<i>k</i>₀ + q <i>K</i>^X/S[MX])/(1 + <i>K</i>^X/S[MX]), where q and <i>K</i>^X/S are empirical constants, MX = NaOC₆H₄CO₂Na and <i>k</i>₀ = <i>k</i>_obs at [MX] = 0. The values of q and <i>K</i>^X/S are explained in terms of pseudophase micellar model coupled with an empirical relationship: <i>K</i>_S = <i>K</i>_S⁰/(1 + <i>K</i>_X/S[MX]), where <i>K</i>_X/S is an empirical constant and <i>K</i>_S and <i>K</i>_S⁰ are CTABr micellar binding constants of PS^- (i.e., S = PS^-) in the presence and absence of MX, respectively. </smarttagtype>