N-烷基二乙醇胺-Ce(Ⅲ)配合物对双(对硝基苯)酚磷酸酯的快速水解研究

Rapid Bis(p-nitrophenyl)phosphate Hydrolysis by N-Alkyl Diethanolamine-Ce(Ⅲ) Complexes

合成了N-正丁基二乙醇胺和长链N-十二烷基二乙醇胺两种配体,在30℃和pH7.20的条件下,研究了这些配体与CeⅢ形成的金属配合物对双对硝基苯酚磷酸酯(BNPP)的催化水解作用,实验发现,这些金属配合物对BNPP有高效快速的催化水解作用,由长链N-十二烷基二乙醇胺-CeⅢ形成的多核功能金属胶束对BNPP的水解作用大于短链的N-正丁基二乙醇胺-CeⅢ金属配合物。在pH7.2时,其水解的表观一级速率常数分别为8.77×10-3s-1和1.62×10-2s-1,为BNPP自发水解的108和109倍,接近于天然酶的活性水平。提出了催化反应的机理,建立了金属胶束和金属配合物催化通用的三元复合物动力学模型,获得了相关的热力学和动力学参数。

N-n-butyldiethanolamine and N-dodecyldiethanolamine were synthesized and characterized by 1H NMR and element analysis in this paper. The hydrolysis of bis(nitrophenyl)phosphate(BNPP) catalyzed by the metal complexes formed between the N-n-butyl diethanolamine and N-dodecyl diethanolamine and Ce(Ⅲ) was studied. The experimental results indicated that N-n-butyldiethanolamine-Ce(Ⅲ) and N-dodecyl diethanolamine-Ce(Ⅲ) functional complexes dramatically accelerated the hydrolysis of BNPP. The functional metallomicelles formed from N-dodecyldiethanolamine-Ce(Ⅲ) with a long chain had a more strong effect on the hydrolysis of BNPP than the N-n-butyl diethanolamine-Ce(Ⅲ) complex which does not form metallomicelles. The observed first order rate constants of the hydrolysis of BNPP catalyzed by N-n-butyl diethanolamine-Ce(Ⅲ) and N-dodecyldiethanolamine-Ce(Ⅲ) functional complexes are 8.77×10-3s-1 and 1.62×10-2s-1,respectively, which are 108 and 109 times of that of spontaneous hydrolysis of BNPP at pH7.They are close to the activity of natural enzyme. A general quantitative treatment of the catalytic reaction involved the ternary complex as MmLlS was also proposed in this paper. With this method the thermodynamic and kinetic parameters of the above catalytic reactions were obtained.