计时电量法测定4,5-二氮芴-9-酮的扩散系数和反应速率常数  

Determination of 4,5-Diazafluorene-9-One Diffusion Coefficients and Rate Constants by Chronocoulometry

作　　者：吕桂琴[1] 马淑贤[1] 

机构地区：[1]北京理工大学化学学院,北京100081

出　　处：《北京理工大学学报》2014年第6期650-654,共5页Transactions of Beijing Institute of Technology

摘　　要：运用循环伏安法测定4,5-二氮芴-9-酮(DAFO)在DMF溶液中不同扫描速率时的循环伏安图,出现2对峰形良好的氧化还原峰;采用计时电量法通过控制阶跃电位,测得不同温度下DAFO在DMF溶液中的扩散系数和反应速率常数,293 K时扩散系数为5.39×10^(—6)cm^2·s^(—1);当选择阶跃电位使电极过程处于扩散和电化学混合控制时,测得不同电位的反应速率常数κ_f.根据不同温度下的标准速率常数κ_0,得到表观活化能E_a为10.5 kJ·mol^(—1).The effect of scan rate on the electrochemical behavior of 4,5-diazafluorene-9-one（DAFO） in DMF solution was studied using cyclic voltammetry method and two pairs of good redox peak were observed.Chronocoulometry was applied to determine the diffusion coefficients and the rate constants（k_f and k_0） of DAFO at different temperatures.The diffusion coefficient was 5.39×10～（-6） cm～2 · s～（-1） at 293 K.The forward rate constants（k_f） at different potentials were obtained when the electrode process was controlled by diffusion and electrochemistry.According to the standard rate constants（k_0）,the activation energy（E_a） of the electron transfer could be calculated as 10.5 kJ·mol～（-1）.

关 键 词：4 5-二氮芴-9-酮 循环伏安 计时电量 扩散系数 反应速率常数 

分 类 号：O646[理学—物理化学]