Accelerated cleavage of P-nitrophenyl picolinate catalyzed by copper(II) and zinc(II) complexes of D-glucosamine schiff base in micellar solution

摘要

The hydrolysis of p-nitrophenyl picolinate (PNPP) catalyzed by the Cu(II) and Zn(II) complexes of d-glucosamine schiff base was investigated kinetically by observing the rates of the release of p-nitrophenol in the buffered micellar solution at different pH and 25 degreesC. The scheme for reaction acting mode involving a ternary complex contain ligand, metal ion and substrate in micelle was establish and the reaction mechanisms were discussed. The experimental results indicated that the complexes catalyzed efficiently the hydrolysis of PNPP, especially Zn(II) complex. The rate constant k(N), which shows the catalytic reactivity of complexes, was determined to be 0.4251 s(-1) for Cu(II) complex at pH 7.60 in micellar solution. The catalytic reactivity of Zn(II) complex were much larger than Cu(II) complex, the k(N) was determined to be 3.1914 s(-1) at same pH value. [References: 18]