论文部分内容阅读
本文提出在水溶液中直接形成CuTPPS络合物,并用极谱、循环伏安、吸收光谱和光谱-电化学等方法研究TPPS和CuTPPS的电还原行为。为了模拟植物体液的pH值,本文在偏酸性的HAc-NaAc底液中(pH4—6)以三种方式快速形成CuTPPS,即溶液加热、室温加维生素C作催化剂以及悬汞电极预吸咐TPPS。实验证明TPPS第一步还原有一对可逆强吸附峰,是2e~-和2H~+电极过程,随后有第二、三步不可逆还原过程,而CuTPPS是不可逆4e~-的还原过程。用自设计长光程汞电极透光电池的光谱-电化学法可求出TPPS和CuTPPS的吸附量和还原电子数,结果与用伏安峰覆盖面积法求得的吸附量相同。并从汞电极上的饱和吸附电量求出吸附的TPPS和CuTPPS的分子面积均为395~2。
In this paper, CuTPPS complex was formed directly in aqueous solution, and the electroreduction behavior of TPPS and CuTPPS was studied by polarography, cyclic voltammetry, absorption spectroscopy and spectroscopic-electrochemical methods. In order to simulate the pH value of plant body fluids, CuTPPS was rapidly formed in acidic HAc-NaAc (pH4-6) in three ways: solution heating, vitamin C as a catalyst at room temperature and pre-adsorption of TPPS . Experiments show that the first step of TPPS reduction has a pair of reversible strong adsorption peaks, which are 2e ~ - and 2H ~ + electrode processes, followed by the second and third step irreversible reduction process, while CuTPPS is an irreversible 4e ~ - reduction process. The adsorption capacity and the number of reduction electrons of TPPS and CuTPPS can be obtained by the spectroscopic-electrochemical method of self-designed long-path mercury electrode cell. The results are the same as those obtained by the voltammetric peak area coverage method. And the molecular area of adsorbed TPPS and CuTPPS was 395 ~ 2 from the saturated adsorption capacity of mercury electrode.