Role of trinuclear Zn(II) complexes in promoting the hydrolysis of 4-nitrophenyl acetate
作者:Qing-Chun Ge、Yan-He Guo、Hai Lin、Dong-Zhao Gao、Hua-Kuan Lin、Shou-Rong Zhu
DOI:10.1139/v03-190
日期:2004.3.1
volume fraction) were studied for the catalyzing hydrolysis of p-nitrophenyl acetate (NA, 0.5~2 × 103 mol·dm3), at 298 K, in the 6.58.2 pH range. The observed rate constants, kobs, fit the equilibrium equation kobs = kcom [3Zn:L]T + kOH[OH] + k0. The sigmoid pH~kcom profiles for NA hydrolysis suggest that either the Zn(II)-bound hydroxyl or the Zn(II)-bound water forms of the catalysts can be the
电位测定表明,四个三脚架的三核 Zn(II) 络合物 1,3,5-tri(2',5'-diazahexyl)benzo (L1), 1,3,5-tri(2',5'-diazaheptyl) )苯 (L2)、1,3,5-三(2',5'-二氮杂辛基)苯 (L3) 和 1,3,5-三(2',5'-二氮杂辛基)苯 (L4) 可以是潜在的水解催化剂。研究了含有 [3Zn:L]T (0.5~2 × 10??3 mol·dm??3) 的 CH3CN 溶液,其中 I = 0.10 mol·dm??3 KNO3 和 Good 缓冲液(10% 体积分数)催化水解对硝基苯乙酸酯 (NA, 0.5~2 × 10??3 mol·dm??3),在 298 K,在 6.5??8.2 pH 范围内。观察到的速率常数 kobs 符合平衡方程 kobs = kcom [3Zn:L]T + kOH[OH??] + k0。NA 水解的