N-甲基二乙醇胺-Ce^(3+)配合物催化水解双(对硝基苯酚)磷酸酯的动力学研究

Kinetic Investigation on the Hydrolysis of BNPP Catalysedby N-Methyl diethanolamine-Ce^(3+ )Complex

作者研究了在(30±0.1)℃,pH7.20的条件下,N 甲基二乙醇胺与Ce3+形成的配合物对双(对硝基苯酚)磷酸酯(BNPP)的催化水解反应及阳离子表面活性剂CTAB和非离子表面活性剂Brij35对催化水解反应的影响,获得了配合物的配位比,并用所建立的MmLlS型三元复合物催化反应的数学模型,得到了催化水解反应相应的热力学和动力学参数.结果表明,配合物中活化的羟基作为亲核物种对磷酸酯有强的亲核反应能力,能有效地促进BNPP的水解,在Brij35存在下,其表观一级速率常数可达到2.5×10-2s-1.

The mathematical model of the catalytic reaction of the ternery complex as M_(m)L_(l)S was proposed in this paper. The thermodynamic and kinetic parameters of the catalytic reaction can be obtained by this method. The hydrolysis of phosphate diester(BNPP) catalyzed by Ce^(3+)complexes was studied kinetically at pH7.20,T=(30±0.1)℃.The effect of Brij35and CTAB surfactants on the hydrolysis of phosphate diester(BNPP) catalyzed by Ce^(3+)complexes was also studied in this paper. The thermodynamic and kinetic parameters of the above-mentioned catalytic reactions were obtained by the mathematical model presented in the paper. The results indicated that the activated hydroxyl group of the ligand is effective nucleophilic species in the hydrolytic reactions. The results showed that the rate for the hydrolysis of phosphate diesterwereincreased 70 ～150 folds, which was caused by metal complex and the concentration effect of surfactant micelle is greater catalyst for the hydrohytic cleavage of phosphate diester