Comparative Reactivities of Metal Cation‐Catalyzed Hydrolysis of p‐Nitrophenyl Picolinate in Micellar Solutions

Abstract

Comparative reactivities of different metal ions in different micellar solutions (cationic, anionic, nonionic micelle) for the hydrolysis of p‐nitrophenyl picolinate (PNPP) were investigated spectrophotometrically at pH 7.0 and 25°C. The kinetics analysis was carried out by invoking a model of micellar catalysis. The results show that compared with metal ions in aqueous solution, cationic micelles inhibit metal ion catalyzed hydrolysis of PNPP, anionic micelles accelerate metal ion catalyzed hydrolysis of PNPP and nonionic micelles show no appreciable effect on metal ion catalyzed hydrolysis of PNPP. The higher the electron charge of metal ions, the greater these effects are, indicating electrostatic interactions are the major reason for metal ion catalyzed hydrolysis of PNPP in micellar solution.

Keywords:

• Catalysis
• Hydrolysis of PNPP
• Metal ion micelle

Acknowledgment

This work is supported by the National Natural Science Foundation of China (Grant No. 273098031 and 20173038).