2，3—二氨基吩嗪的薄层光谱电化学研究

研究了2，3—二氨基吩嗪(DAP)在金圆盘电极、金超微电极上的循环伏安行为 和在金网栅电极上的薄层循环伏安行为．在pH2．0的B—R缓冲溶液中的2，3—二氨 基吩嗪在金圆盘电极上为准可逆氧还过程；以超微电极法求得了2，3—二氨基吩嗪 在pH2．0的B—R缓冲溶液中的扩散系数，由耗竭性库仑电解和循环伏安法求得其电 极反应电子转移数和H+反应级数均为2，实验说明参与电极反应的H+也为2，并用循 环伏安法求得其标准电极反应速率常数．采用紫外—可见薄层光谱电化学方法测得 2，3—二氨基吩嗪的克式量电位和电子转移数，与电化学实验结果一致；双电位阶 跃—计时吸收紫外—可见薄层光谱电化学实验说明，2，3—二氨基吩嗪电还原无随 后化学反应，其在电极上经历了H+eH+e的两步一电子过程，生成产物2，3—二氨基 -5，10-二氢吩嗪．

An Electrochemical and Thin-layer Spectroelectrochemical Study of 2, 3-Diaminophenazine

Cyclic voltammetry with a gold disc electrode and thin layer cyclic voltammetry with a gold minigrid electrode of 2,3 diaminophenazine (DAP) solutions in Britton Robinson (B R) buffer appear a pair of quasi reversible redox peak. The diffusion coefficient and the standard rate constant of the electrode reaction of DAP in pH 2.0 B R buffer are determined respectively, by cyclic voltammetry on a gold ultra microelectrode and on a gold disc electrode. The electron transfer number as well as H + order of the reaction is 2 from the results of the bulk electrolysis with coulometry and cyclic voltammetry. The formal potential of DAP is determined by UV vis thin layer spectroelectrochemistry. The electron transfer number from UV vis thin layer spectroelectrochemistry is in accordance with the result of above electrochemical experiment. The double potential step UV vis thin layer chronoabsorptiometry indicates that the electroreduction of DAP is not followed by chemical reaction. The reduction of DAP occurs via an H +eH +e electrochemical mechanism and leads to 2,3 diamino 5,10 dihydrophenazine as product.