合成了5种不同结构的席夫碱(N-苯基苯甲亚胺、具有-OH基团的N-苯基-2-羟基苯甲亚胺和N-(2-羟基)苯基苯甲亚胺、具有-NO2基团的N-苯基-4-硝基苯甲亚胺和N-(4-硝基)苯基苯甲亚胺).利用循环伏安法对5种席夫碱水溶液在玻碳电极上的电化学氧化还原行为进行了研究.同时考察了pH对席夫碱-CH=N-基团的电化学氧化还原反应的影响.结果表明:这5种席夫碱的-CH=N基团都可以在玻碳电极上被还原,且是一个电化学上不可逆的过程;席夫碱结构上具有不同的取代基团(-OH和-NO2)和同一取代基团在席夫碱不同的位置上(与碳端相连苯环、与氮端相连苯环)对-CH=N-基团的电化学还原都有较大的影响;而在不同pH缓冲溶液中,H+浓度对5种席夫碱的-CH=N-基团还原也有一定的影响;进而推断出席夫碱在玻碳电极上的电化学还原机理是-CH=N-基团上先在N原子上先得到一个电子,后在C原子上得到一个电子,再得到两个H+的过程.%Five kinds of Schiff bases with different structures were synthesized (N-phenyl benzoylimine, N-phenyl-2-hydroxyl benzoylimine and N-(2-hydroxyl) phenyl benzoylimine which possessed -OH, N-phenyl-4-nitryl benzoylimine and N-(4-nitryl) phenyl benzoylimine which possessed -NO2). Cyclic voltammetry technique was used to investigate electrochemical redox behavior of these Schiff bases at glassy carbon electrode. Meanwhile, effect of pH on electrochemical redox reaction of Schiff bases was studied. The results demonstrated that these Schiff bases at glassy carbon electrode could be deoxidized and electrochemical reduction was an irreversible process; both different substituting groups (-OH and -NO2) in benzene and the same substituting group in different positions(benzene joined with carbon, benzene joined with nitrogen) had effects on electrochemical deoxidization of -CH ＝ N- group; in a buffer solution with varying pH, the concentration of H+ affected electrochemical deoxidization of -CH ＝ N- group; it was deduced that the mechanism for the electrochemical reduction process of -CH ＝ N- group was that firstly one electron was acquired in nitrogen, secondly one electron was acquired in carbon, and at last two protons were acquired.
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