Aminolysis reactions by glycine in AOT-based water-in-oil microemulsions

A kinetic study was carried out on the aminolysis of p-nitrophenyl acetate (NPA) by glycine (GLY) in AOT/isooctane/water (w/o) microemulsions. The experimental results show that the reaction by GLY occurs mostly in the aqueous microdroplet. On the basis of the analysis of the kinetic data, we have calculated the rate constants in the aqueous microdroplet, k(2)(w), and it can be observed that these increase as the water content of the system decreases. In the aqueous microdroplet, the predominant interaction Na+...OH2 causes a decrease in the strength of the hydrogen bonds and therefore facilitates the desolvation of the reagents as W decreases. This desolvation of the reagents causes the increase of k(2)(w) as W decreases. (c) 2005 Elsevier B.V. All rights reserved.