氮杂-12-冠-4取代的单Schiff碱锰(Ⅲ)配合物对羧酸酯水解的催化作用

Carboxylic Ester (PNPP) Hydrolysis Catalyzed by Magnesium(III) Complex with Monoaza-12-Crown-4 Substituted Salicylaldimine Schiff Base Ligand

合成了N [4 ( 2 羟基苯亚甲基亚胺基 )苯甲基 ] 单氮杂 1 2 冠 4锰 (III)配合物 (MnL1 2Cl) .研究了MnL1 2 Cl催化PNPP水解的动力学 ,分析了反应体系的紫外光谱变化 ,提出了催化反应的机理 .结果表明 ,在中性、碱性和室温 ( 2 5℃ )条件下 ,MnL1 2 Cl能够有效地催化水解PNPP .在底物浓度大于配合物浓度 1 0倍以上时 ,PNPP催化水解的表观一级速率常数遵循方程kob=kK[S]/(K + [S]) .

A new magnesium(III) complex (MnL 1_2Cl) with monoaza-12-crown-4 substituted salicylaldimine Schiff base ligand was synthesized. The hydrolytic kinetics of PNPP catalyzed by the complex was studied. The ultraviolet spectrums of the reaction system were also analyzed. The mechanism of PNPP catalytic hydrolysis was proposed according to the results of the spectrums analysis. The results showed that the MnL 1_2Cl can effectively catalyze PNPP hydrolysis under a neutral or basic condition;at the condition of more than 10-fold excess of substrate over the complex concentration,the apparent first order order rate constant of PNPP catalytic hydrolysis can be calculate according to the equation k_ ob= kK/ (K+).