Kinetic evidence for near irreversible nonionic micellar entrapment of N-(2'-Methoxyphenyl)phthalimide (1) under the typical alkaline reaction conditions

The values of pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 1, obtained at 1.0 mM NaOH and within [C(m)E(n)]T (total concentration of C(m)E(n)) range of 3.0-5.0 mM for C(12)E(23) and 10-20 mM for C(18)E(20), fail to obey pseudophase micellar (PM) model. The values of the fraction of near irreversible C m E n micellar trapped 1 molecules (F(IT1)) vary in the range ~0-0.75 for C(12)E(23) and ~0-0.83 for C(18)E(20) under such conditions. The values of F(IT1) become 1.0 at ≥ 10 mM C(12)E(23) and 50 mM C(18)E(20). Kinetic analysis of the observed data at ≥ 10 mM C(12)E(23) shows near irreversible micellar entrapment of 1 molecules under such conditions.