四苯卟啉及其第一过渡金属配合物推动H^+通过水/硝基苯界面的机理研究

Mechanism Study of H^+ Ion Transfer across Water/Nitrobenzene Interface Assisted by Tetraphenylporphyrin and Its First Transition Metal Coordination Compounds

应用具有以正反馈技术补偿溶液电阻降功能的微机联用四电极恒电位测试系统研究了四苯卟啉(H_2TPP)及其第一过渡金属配合物(MTPP)对H^+在水/硝基苯界面转移的影响.结果表明,H_2TPP和MTPP对上述H^+转移过程均表现出一定程度的活性.当水相H^+浓度甚低于NB相的H_2TPP浓度时,后者推动H^+在W/NB界面的转移呈可逆并受扩散步骤控制.各MTPP对推动H^+通过W/NB界面的相对活性表现为NiTPP>MnTPP>CoTPP,CuTPP>ZnTPP,FeClTPP,与金属卟啉配合物的热稳定性一致. 根据实验事实,提出有关H同_2TPP推动H^+迁过W/NB界面的微观动力学机理.

The effects of tetraphenylporphyrin (H_2TPP) and its first transition-metal coordination compounds (MTPP) on H^+ ion transferring across the water/nitrobenzene (NB) interface had been investigated by using the system of microcomputer controlled four-electrode potentiostat with the positive feedback. The results showed that H_2TPP and MTPP did assist the H^+ ion transferring across the W/NB interface to different extent. Under the condition of H^+ concentration (W) being lesser than the H_2TPP concentration (NB), the process of H^+ ion transferring across the W/NB interface faciliated by H_2TPP was reversible and diffusion-controtted. As far as the MTPP was concerned, the sequence of their relative activities is: NiTPP>MnTPP>CoTPP, CuTPP>ZnTPP, FeClTPP, this order consisted with the sequence of their stabitity. Based on the experimental results, an apparent kinetic mechanism of H^+,ion transferring across the W/NB interface facilitated by H_2TPP was proposed.