【摘要】 合成了不对称氮氧杂链型配体Ｎ－（２′－羟基）苄基乙醇胺（ＨＬ），通过元素分析、ＩＲ和１ＨＮＭＲ等手段进行了表征。用ｐＨ电位滴定法，在２５±０．１℃，Ｉ＝０．１０（ＫＮＯ３）条件下，研究了该配体质子化及其与Ｃｕ（Ⅱ）离子配位热力学。在２５±０．１℃，Ｉ＝０．１０（ＫＮＯ３），ｐＨ＝７～９（５０ｍｏｌ·Ｌ－１缓冲溶液）范围内，通过分光光度法测定了配合物对ｐ－硝基苯酚乙酸酯（ＮＡ）水解催化动力学，得到了ＮＡ酯催化水解二级反应速率常数ｋＮＰ（（ｍｏｌ·Ｌ－１）－１·ｓ－１）。结果表明：Ｃｕ（Ⅱ）离子与醇羟基配位作用较强，并且还与一个水分子有较弱的配位。配位醇羟基和水分子的离解常数ｐＫａ分别为７．６２和１１．２２。在中性ｐＨ值可以产生具有有很强亲核能力的配位烷氧负离子Ｃｕ（Ⅱ）…－ＯＲ，配合物对酯的水解有金属离子Ｌｅｗｉｓ酸活化和亲核试剂进攻双重催化作用，与碱性磷酸酯催化作用比较类似，在ｐＨ中性和弱碱性条件下对ＮＡ酯水解有很好的催化效果，当ｐＨ为９．０时，ｋＮＰ达到０．１２（ｍｏｌ·Ｌ－１）－１·ｓ－１。更多还原

【Abstract】 A new unsymmetrical ONO tridentate chain ligand N (2′ hydroxyl) benzyl ethanolamine has been synthesized and characterized by elemental analysis, IR and 1NMR. Thermodynamics of its protonation and complexation with Cu(Ⅱ) ion has been investigated by potentiometric pH titration at 25±0.1℃, and I =0.10 (KNO 3). Kinetics of p nitrophenyl acetate (NA) hydrolysis catalyzed by the complexes has been studied spectrophotometrically at 25±0.1℃, and I =0.10 (KNO 3) in 10% ( V/V ) CH 3CN aqueous solution at pH 7￣9 (50 mmol·L -1 buffers), and the second order rate constants k NP were obtained. The experimental results indicate that Cu(Ⅱ) coordinates strongly with the alcoholic hydroxyl in the ligand and also coordinates weakly with a water molecule with p K a values of 7.62 and 11.22 for them respectively. the complexes effectively catalyze NA hydrolysis at neutral and weak alkaline pH with a k NP value of 0.12 (mol·L -1 ) -1 ·s -1 at pH 9.0. According to a double catalysis mechanism, Lewis acid activation by metal ion and nucleophilic attack by Cu(Ⅱ) bound alkoxide, is somewhat similar to that of alkaline phosphatase catalyzed ester hydrolysis.更多还原