金属胶束催化VIII:肟基铜(Ⅱ)配合物催化羧酸酯水解反应研究  

Metallomicellar Catalysis VIII: Hydrolyses of Carboxyl Acid Esters Catalyzed by Copper (Ⅱ) Oximato Complexes

作　　者：蒋炳英[1] 黄忠[1] 蒋维东[1] 谢飞[1] 胡常伟[1] 曾宪诚[1] 

机构地区：[1]四川大学化学学院,四川成都610064

出　　处：《四川大学学报（自然科学版）》2004年第1期148-154,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(29873031;20173038)

摘　　要：合成并表征了单核和双核肟基铜(Ⅱ)配合物,研究了这两种配合物在不同胶束体系中催化羧酸酯水解的动力学,用相应的动力学模型处理得到了相关的动力学和热力学参数.研究结果表明,两种配合物在阳离子表面活性剂CTAB(十六烷基三甲基溴化铵)所生成的胶束溶液中催化PNPP(对硝基苯基α 吡啶甲酸酯)和PNPA(对硝基苯基乙酸酯)水解的活性高于在非离子表面活性剂胶束Brij35(聚氧乙烯(23)十二烷基醚)中的催化作用;单核Cu(II)配合物在金属胶束相中催化PNPP水解和双核Cu(II)配合物在金属胶束相中催化PNPA水解的一级速率常数与它们在缓冲溶液中自发水解的速率常数相比,kN分别提高了大约20747倍和32014倍.Two copper(II) oximato complexes, mononuclear Hd and binuclear ClO_(4)H_(2)O (H_(2)dmg: Dimethylglyoxime), were synthesized and characterized. And hydrolyses of carboxyl acid esters, p-nitrophenyl picolinate (PNPP) and p-nitrophenyl acetate (PNPA), catalyzed by these two complexes were investigated in different micellar systems in the pH range from 6.58～8.65 at 25℃. The results obtained in this paper suggested that, both complexes accelerate the hydrolytic cleavage of PNPP and PNPA in cationic CTAB micellar solution faster than that in nonionic Brij35 micellar solution.In addition, the interesting phenomenon observed was that, for binuclear Cu(II) complex, the rate constant (k_(N)) for the hydrolysis of PNPA was about two times larger than that for PNPP in CTAB micellar solution, while in Brij35 micellar solution, the k_(N) values for PNPA and PNPP are roughly the same, and which may be due to the combination of configuration of intermediate formed during the reaction process and electrostatic interaction between micelle and reactants.

关 键 词：肟基配合物 羧酸酯 水解 动力学处理 

分 类 号：O643.32[理学—物理化学]