化学学报 ›› 1965, Vol. 31 ›› Issue (1): 18-28. 上一篇    下一篇

论文

锑(Ⅲ)-乙二胺四乙酸络合物的极谱研究

汪尔康1, 张仁斌2   

  1. 1. 中国科学院应用化学研究所;
    2. 中国科学院药物研究所
  • 投稿日期:1963-09-20 发布日期:2013-06-03

POLAROGRAPHIC STUDY OF ANTIMONY (Ⅲ) COMPLEX WITH ETHYLENEDIAMINETETRA-ACETIC ACID

WANG ER-KANG1, CHANG JEN-PING 2   

  1. 1. Institute of Applied Chemistry;
    2. Institute of Materia Medica, Academia Sinica
  • Received:1963-09-20 Published:2013-06-03

在酸性4M氯化钠溶液中得到一很好的锑(Ⅲ)可逆扩散波.此波随加入乙二胺四乙酸量而减低、且稍向负电位移动,在更负电位处又出现另一不可逆波,二波之和与溶液pH和乙二胺四乙酸的浓度无关.经多种实验的验证,第一波(较正波)为可逆三电子反应动力波,是受络合物SbY的离解速率控制.用Koryta提出的动力波半波电位求络合物稳定常数的方法测定锑(Ⅲ)-乙二胺四乙酸络合物的稳定常数和反应自由能等热力学函数;用Hanus近似法推出动力电流方程式,测定络合物离解速率常数和反应活化能;并探讨各相应的电极过程.

The polarographic behaviour of antimony(Ⅲ) complex with ethylenediaminetetraacetic acid (EDTA), including the calculation of stability constants, thermodynamic functions, and the mechanism of the complex formation, has not yet been studied in detail.In acidic 4 M sodium chloride solution, there is one cathodic diffusion wave corresponding to three electrons reversible electrode reaction of antimony(Ⅲ) at about -0.132 V (vs.S.C.E.) and pH 1.63.If to a strongly acidic solution EDTA is added even in high concentration, it exerts practically no influence on this wave.But if it is added to weakly acidic solutions (e.g.pH>2), there appears another wave which corresponds to the three electrons electrode reaction as before but at more negative potentials (e.g.at about -0.55 V at pH 2).If either the pH or the concentration of EDTA is reduced, the height of the second (more negative) wave decreases, while the first one appears again.The sum of both waves is constant and is independent of the concentration of EDTA and the pH value.