叶绿素的电化学行为研究Ⅲ锌－去镁叶绿素的伏安行为

在文Ⅰ、Ⅱ中报道了叶绿素（Ch1）的一种电化学分析方法，讨论了叶绿素a，b电还原的机理以及去镁叶绿素（pheophytin）和它的一种金属叶绿素（MCh1）CuCh1的伏安特性。本文报道锌－去镁叶绿素（ZnCh1或ZnPheo）的伏安行为，并与CuCh1的行为相比较，用以观察植物生长必需的另一重要微量元素锌在置换叶绿素中镁离子后的电化学氧化－还原性能，并指出它们的异同。

Studies on the Electrochemical Behaviors of Chlorophyll III Voltammatric Behaviors of Zn-Chla

The magnesium ion in chlorophyll(Chl) can be displaced by Zincion to form Zn-Chl. Since the porphyrin ring part of Chl is hydrophillic and the phytol chain part of Chl is hydrop-hobic, so the electro-reduction behavior of Zn-Chl is somewhat similar to the water-soluble Zn-TPPS, but not exactly the same. The voltammetric behaviors of Zn-Chla and Cu-Chla are different, the former is reduced with 2e^-, while the latter with 4e^-. The reduction product of Zn-Chla may be in the form of ZnChla·2H, which can be observed at high scan rate above 1.5 V/s. By the method of kinetic analysis, the surface reaction constant of the product, k⁰, has beenfound to be 8.1 s^-1.