流动电解池中现场紫外光谱法亚胺醌水解反应动力学的研究  

IN SITU UV SPECTROELECTROCHEMICAL STUDY ON THE CHANNEL CELL KINETICS OF p-BENZOQUINONEIMINE HYDROLYSIS REACTION

作　　者：李勋[1] 唐艳辉[1] 吴义熔[1] 汪正浩[1] 

机构地区：[1]北京师范大学化学系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2001年第6期790-794,共5页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目 (2 96 730 0 6 )

摘　　要：使用流动电解池在波长 2 6 5nm处 ,于H2 SO4 +K2 SO4 缓冲溶液中 ,测定了对氨基酚电化学氧化中间产物亚胺醌的吸光度A随体积流量 qV和入射光位置x的变化 .以x与最大吸光度Amax所对应的体积流量 qVm作图 ,它满足lgqVm对lg(- 4 .4 5 + 4 .72 x/xe)是一条斜率接近 1的直线 .根据数值解结果 ,由直线的截距可求出亚胺醌的水解速率常数k1.比较了所用的固定波长法和在以前工作中采用的吸收谱拟合法 ,分析了 2种方法的优缺点及适用条件 ,给出了使用固定波长法在不同 pH值下测得的亚胺醌的k1.In a spectroelectochemical channel flow cell the change of absorbance of p-benzoquinoneimine is monitored at 265 nm as a function of flow velocity and incident light position, where p-benzoquinoneimine is electogenerated from p-aminophenol oxidation reaction in H 2SO 4+K 2SO 4 buffered solution. Fitting lgq Vm with lg(-4.45+4.72x/x e), where q Vm is the flow velocity corresponding to the maximum absorbance and x is the position of incident light point, x e is the length of the working electrode, a good linear relationship with a slope close to unity is obtained. According to the results of numerical simulation, the rate constant of BQI hydrolysis k 1 is calculated from the intercept of the line. The method of fixed wavelength and the fitting spectra method applied in previous study are compared, and their characteristics and suitable conditions for their application are analyzed. The rate constant of BQI hydrolysis are also determined at various pH values using the method of fixed wavelength.

关 键 词：光谱电化学 EC反应 亚胺酯 水解反应动力学 流动电池解 水解速率 氧极氧化过程 

分 类 号：O625.461[理学—有机化学] O657.13[理学—化学]