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

使用流动电池池在波长265nm处，于H2SO4 K2SO4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(-4.45 4.72x/xc)是一条斜率接近1的直线。根据数值解结构，由直线的截距可求出亚胺酯的水解速率常数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 SITU UV SPECTROELECTROCHEMICAL STUDY ON THE CHANNEL CELL KINETICS OF p-BENZOQUINONEIMINE HYDROLYSIS REACTION

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.