Effect of microemulsion-like polysoap on the catalysed esterolysis of hydrophobic p-nitrophenyl esters

The esterolytic activity of metal ion complexes of n-alkyl-2-hydroxymethylbenzimidazoles /Zn2+ towards p-nitrophenyl eaters (picolinates and alkanoates) was investigated in the presence of an amphiphilic polymer, poly(1-hexadecyl-3 -vinyl-pyridinium bromide), as a macromolecular matrix. The reaction rate constants obtained for the polymer hydrophobic microdomains were compared with those observed for the new conventional surfactant, 3-ethyl-1 -hexadecylpyridinium bromide, chosen as the model of the repeat unit of the homopolymer. In both cases, the kinetic analysis indicated that the esterolysis reaction proceeds through the formation of an initial binary complex Ligand-Zn2+, the stoichiometry of which is 2/1 type. (C) 1999 Elsevier Science B.V. All rights reserved.