【作者】 臧蓉蓉；

【导师】 孟祥光；

【作者基本信息】 四川大学 ， 物理化学， 2005， 硕士

【摘要】 水解金属酶的化学模拟是当前化学与仿生学研究的前沿之一。用胶束尤其是金属胶束模拟水解酶的研究已成为近年来十分活跃的研究领域。本论文围绕胶束、金属配合物及其金属胶束催化对硝基苯基吡啶甲酸酯(PNPP)水解反应的动力学等进行了较深入系统的研究。研究结果对了解酶的催化作用的机理以及设计高效的人工酶模型提供了一定的理论依据和有用的信息。为研究配合物立体构型对酯水解过程的影响,本论文以开环的二氧环胺二价过渡金属Ni(II)配合物作为羧酸酯水解酶的模拟酶模型,研究其与不同表面活性剂形成的金属胶束催化PNPP 水解的动力学,探讨金属配合物空间结构以及表面活性剂胶束对反应的影响。动力学结果表明,配合物几何构型对PNPP 水解有较大的影响,配体空间位阻越小越有利于PNPP 的水解;配合物在阳离子表面活性剂形成的胶束溶液中对PNPP 水解催化作用不如在两性离子表面活性剂LSS 和非离子表面活性剂Brij35 胶束溶液中对PNPP 水解的催化作用,　这可能是由于底物和CTAB 的阳离子极性头之间产生静电吸引作用造成的。　为探索不同金属离子在酯水解过程中的作用,本论文合成了两种Schiff 碱类的的铜(II)和镍(II)配合物,并系统研究了两种配合物与阳离子表面活性剂CTAB 形成的金属胶束催化羧酸酯PNPP 的催化水解动力学和机理。实验结果表更多还原

【Abstract】 The chemical functional mimicry of hydrolytic metalloenzyme is one of frontier research fields in chemistry and bionics. Recently, micelle, metal complex, especially metallomicelle made of metal complex and micelle as model systems for artificial hydrolytic enzyme are the very active research fields. This dissertation focuses on the following aspect: the hydrolysis of p-nitrophenyl picolinate (PNPP) catalyzed by metal complex and metallomicelle. The results obtained may provide theoretical basis and significative information for finding out the hydrolytic mechanism of enzymes and for designing highly efficient artificial enzyme model systems. For the purpose of studying the influence of the geometry of metal ion coordination on the hydrolysis of the carboxylic ester, the hydrolysis of PNPP catalyzed by metallomicelles made of Ni(II) complexes of bis(dioxocyclam) and three kinds of surfactants(CTAB, Brij35 and LSS) have been investigated kinetically, respectively. The results suggested that the open ring Ni(II)complex exhibited a greater catalytic activity in LSS micellar solutions than that in CTAB and Brij35 micellar solutions, which may be due to the different coordinating ability of substrates to complexes and the electrostatic interaction between micelle and complexes or substrates. Moreover, it is worth noting that the catalytic activity in the Ni(II) complex on the hydrolysis of PNPP also depends on the space hindrance of complex. Small space hindrance of complex is favorable for the catalytic hydrolysis of the substrate . In order to elucidate the effects of different metal ions on hydrolysis of esters, two Schiff base Cu(II) and Ni(II) complexes were synthesized and characterized. The hydrolysis of PNPP catalyzed by these two complexes was investigated in CTAB micellar systems. The results obtained indicate that Cu(II) complex with open ring ligand exhibited highly catalytic activity on the hydrolysis of PNPP, which may be due to the different coordinating ability of the substrates to complexes and the electrostatic interaction between micelle and complexes or substrates. With the development of surfactant chemistry, researchers have paid much more attention to Gemini surfactant owing to its unique properties. The hydrolysis of PNPP mediated by dimethylene-1,2-bis(dodecyltrimethylammonium bromide)(12-2-12, 2Br-), compared with cationic Gemini dimethylene-1,2-bis(cetyltrimethylammonium bromide)(16-2-16, 2Br-) were investigated kinetically. It was noteworthy that long hydrophobic chain Gemini surfactant micellar system enhanced the hydrolysis of carboxylic acid esters more notably than the short one did, which provide useful information to understand the effect of microenvironment of mimicking esterase.更多还原