卟啉配位剂meso－四（对－羧基苯基）卟啉（H_2TCPP）极谱行为的研究

Polarographic Study on the Behavior of meso-Tetra(p-carboxyphenyl) Porphyrin(H_2TCPP)

采用直流极谱和循环伏安等多种手段研究了卟啉配位剂（Ｈ２ＴＣＰＰ）在汞电极上的极谱性质，在碱性介质中，Ｈ２ＴＣＰＰ的电极反应具有以下三个特性：（１）第一步为受扩散控制的２ｅ并有２Ｈ＾＋参与的可逆还原过程，第二和第三步为不可逆各为２ｅ的还原反应：（２）Ｈ２ＴＣＰＰ在汞电极上存在强吸附性；（３）第一步电极反应产物可发生随后的化学反应，即前两步还原经由ＥＣＥ机理进行。

The electrochemical reduction of meso-tetra-(p-carboxyphenyl)porphyrin(H2TCPP)has been investigated by polarography and cyclic voltammetry,In alkaline solutions,the electrode reaction of H2TCPP has the following three characteristics:(i)the first step of reduction is a 2e reversible electrode process,involving 2H+,while the second and third steps might be 2e irreversible reduction waves:(ii)H2TCPP was firmly adsorbed on the mercury electrode;and (iii)the first two steps of H2TCPP have been shown to be involved in an ECE mechanism.