高等学校化学学报 ›› 1981, Vol. 2 ›› Issue (3): 265.

• 论文 •    下一篇

HPZL和TBP对金属离子的萃取和协同萃取机理

黎乐民, 徐光宪   

  1. 北京大学化学系
  • 收稿日期:1980-03-20 出版日期:1981-08-24 发布日期:1981-08-24

STUDY OF THE MECHANISM OF CHELATE AND SYNERGISTIC EXTRACTION OF Pb++, Ni++, Mn++, Co++, Cd++, Ca++, Mg++ AND La+++ IONS WITH PYRAZOLONE-TBP-BENZENE

Li Le-min, Hsu Kwang-hsien   

  1. Department of Chemistry, Peking University, Beijing
  • Received:1980-03-20 Online:1981-08-24 Published:1981-08-24

摘要: 本文报导用两相滴定法研究HPZL和TBP的苯溶液对Pb++、Ni++、Mn++、Co++、Ca++、Mg++、Cd++、La+++诸离子的萃取和协同萃取机理得到的结果。 1.确定了有关萃合物和协萃络合物的组成和相应的平衡常数。 2.实验表明,萃取作用比较强的金属离子,协萃效应比较弱;而萃取作用比较弱的金属离子协萃作用则较强。所以,萃取性能比协萃性能更反映出金属离子之间的差异。 3.发现配位数和配位键的共价性之间有以下关系:若配位键的共价性较强,则配位数倾向于取较小的值,协同效应较弱;若配位键的离子性较强,则配位数倾向于取较大的值,协萃效应较强。

Abstract: The mechanism of chelate and synergistic extraction of Pb++,Ni++,Mn++,Co++ Cd+++,Ca++, Mg++ and La+++ ions with l-phenyl-3-methyl-4-benzoyl-pyrazolone-5(HPZL)-benzene and HPZL-TBP-benzene solution were investigated by the two-phase titration method. The composition of the extracted chelates and synergistic complexes and their stability constants have been determined. The experimental results showed that for the metal ions which are extracted strongly the synergistic effects are weaker, while the metal ions extracted weakly exhibit stronger synergistic effect. It was also found that there exist some relation between the coordination number and the cova-lent character of the coordinate bond. If the coordinate bond has more cova-lent character, the coordination number tends to take the smaller value and the synergistic effect is weaker. On the other hand, if the coordinate bond has more ionic character, the coordination number tends to take the larger value and the synergistic effect is stronger.

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