抄録
In order to examine the catalytic action of imidazole in nonaqueous solutions of nonionic surfactants, the pseudo-first-order rate constants (kobs) for the reaction between p-nitrophenyl acetate and imidazole in carbon tetrachloride was measured as a function of the concentration of imidazole at fixed molar ratios (0.5, 1.0, 2.0) of imidazole to surfactants. By analyzing of kobs-[Imidazole] profile obtained, the second and third rate constants (k2, m and k3, m) for imidazole monomer and the catalytic rate constant (kA) for imidazole aggregates were obtained. Both k2, m and kA values increase with the increase in the molar ratio or the oxyethylene chain length of surfactants, but the increase is small for k2, m. The catalytic action of imidazole in water solubilized into the imidazole/surfactant/CCl4 systems is enhanced with decrease in polarity of the interior of aggregates.
