【作者】 蒋维东； 徐斌； 刘富安；

【Author】 Weidong Jiang;Bin Xu;Fuan Liu;Key Laboratory of Green Catalysis of Sichuan Institute of High Education;School of Chemical and Pharmaceutical Engineering,Sichuan University of Science & Engineering;

【机构】 绿色催化四川省高校重点实验室； 四川理工学院化学与制药工程学院；

【摘要】 天然水解金属酶大多拥有双金属或多金属活性中心,兼具疏水微环境,其具有高效、高选择催化酯键水解的功能[1]。金属胶束作为一类模拟水解金属酶配位、疏水、静电作用方式的优良体系而广受关注[2]。本文研究了一种烷氧/氢氧桥联的水杨醛类Schiff碱双核铜(II)配合物(Cu2L)在Gemini 16-6-16、16-2-16、CTAB、DHAB以及LSS胶束中催化α-吡啶甲酸对硝基苯酯(PNPP)水解的反应性。研究发现,在四种阳离子胶束体系中均获得4个数量级以上的速率增加,16-6-16胶束中PNPP水解反应获得更为明显的加速。此配合物优异的催化活性主要源于其双金属活性中心的协同活化作用,同时,氢氧桥通过其与底物PNPP分子中羰基间的氢键作用协同活化底物,增强底物的亲电活性,从而有利于底物的水解。另外通过对比研究,在可比条件下(pH 7.00,[Catalyst]=0.01mM),16-6-16胶束中PNPP催化水解速率是其它四种胶束体系中的水解速率的2.6-25倍左右(Fig.1),这与16-6-16自身更为优越的表面活性有关[3]。更多还原

【Abstract】 This study reports that effects of five kinds of micelles, i.e., 16-6-16, 16-2-16, CTAB, DHAB and LSS, on the catalytic hydrolysis of p-nitrophenyl picolinate(PNPP) by an alkoxo/hydroxo-bridged dinuclear copper(II) complex(Cu2L) with salicylaldehyde-type Schiff base. The results reveal that the as-prepared dinuclear Cu2L exhibited good reactivity arousing excess four order of magnitude rate enhancement in these micellar media except LSS. The remarkable activity of Cu2L probably results from bimetallic synergistic effect and a hydrogen bond activation of Cu2L. Moreover, a micellar solution of 16-6-16 provided the best reaction medium for the PNPP hydrolysis in contrast with the other media, representing about 2.6~25-folds kinetic advantage under comparable conditions, which is probably contributed to its more dominative properties of 16-6-16.更多还原