高等学校化学学报 ›› 1989, Vol. 10 ›› Issue (12): 1189.

• 研究论文 • 上一篇    下一篇

铬(Ⅵ)-邻菲咯啉-亚硝酸钠的氨性缓冲体系中极谱催化波机理的研究

韩吉林, 陈洪渊, 高鸿   

  1. 南京大学化学系
  • 收稿日期:1988-06-14 出版日期:1989-12-24 发布日期:1989-12-24
  • 通讯作者: 陈洪渊
  • 基金资助:

    国家自然科学基金

Studies on the Mechanism of the Polarographic Catalytic Wave of Chromium(Ⅵ) in the Buffer System of (o-Phen)-NaNO2-NH3-NH4Cl

Han Jilin, Chen Hongyuan, Gao Hong   

  1. Department of Chemistry, Nanjing University, Nanjing
  • Received:1988-06-14 Online:1989-12-24 Published:1989-12-24

摘要: 本文报道了Cr(Ⅵ)-C12H8N2-NaNO2-NH3-NH4Cl(pH9.4)体系极谱催化波机制的研究.阐明它不是氢催化波.而是Cr(Ⅲ)的多元配合物中NO2-被催化还原,同时溶液中的NO2-又参与了平行电极反应的催化反应.活性多元配合物的组成为:Cr(Ⅲ)·(C12H8N2)·(NO2-)2·(NH3).

关键词: 铬, 催化波, 条件形成常数, 混配化合物

Abstract: Anew viewpoint elucidating the mechanism of a highly sensitive polarographic catalytic wave of Cr(Ⅵ) in the medium of 1,10-phenanthroline-nitrite-NH3-NH4Cl (pH 9.4) is presented.This wave is not a catalytic hydrogen wave, but a catalytic (EC-EC') reaction in which Cr(Ⅵ) is firstly reduced to Cr(Ⅲ), then it forms a multi-coordination compound A (as electroactive species) in the following chemical reaction.In the second step of the electrode reaction, the ligand NO2- in the compound Ais reduced, then the product of Ais oxidized by NO2- in solution to regenerate the starting material Aagain.The composition of the multi-coordination compound and the conditional formation constant for various ligands are determined.

Key words: Chromium, Catalytic wave, Conditional formation constant, Multi-complex

TrendMD: