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-hydroxymethylb enzimidazoles /Zn2+ towards p-nitrophenyl eaters (picolinates and alkanoate s) was investigated in the presence of an amphiphilic polymer, poly(1-hexad ecyl-3 -vinyl-pyridinium bromide), as a macromolecular matrix. The reaction rate constants obtained for the polymer hydrophobic microdomains were comp ared with those observed for the new conventional surfactant, 3-ethyl-1 -he xadecylpyridinium bromide, chosen as the model of the repeat unit of the ho mopolymer. In both cases, the kinetic analysis indicated that the esterolys is reaction proceeds through the formation of an initial binary complex Lig and-Zn2+, the stoichiometry of which is 2/1 type. (C) 1999 Elsevier Science B.V. All rights reserved.