高等学校化学学报 ›› 1998, Vol. 19 ›› Issue (12): 1992.

• 论文 • 上一篇    下一篇

ⅡB族金属离子-α-氨基酸-二酮肟配体三元体系稳定性研究

张耀山, 汪中明, 林华宽, 朱守荣, 孙宏伟, 王登国, 陈荣悌   

  1. 南开大学化学系, 天津, 300071
  • 收稿日期:1997-01-31 出版日期:1998-12-24 发布日期:1998-12-24
  • 通讯作者: 林华宽
  • 作者简介:张耀山,男,55岁,副教授,四川三峡学院访问学者.
  • 基金资助:

    国家自然科学基金(批准号:29671020)资助课题.

Studies On the Stability of Group Ⅱ B Metal Ion-α-amino Acids-diketooxime Ternary Systems

ZHANG Yao-Shan, WANG Zhong-Ming, LIN Hua-Kuan, ZHU Shou-Rong, SUN Hong-Wei, WANG Deng-Guo, CHEN Rong-Ti   

  1. Department of Chemistry, Nankai University, Tianjin, 300071
  • Received:1997-01-31 Online:1998-12-24 Published:1998-12-24

摘要: 在(35.0±0.1)℃, I=0.1mol/LKNO3条件下,用pH法测定了3,3,9,9-四甲基-4,8-二氮杂十一烷-2,10-二酮肟配体(PnAO)和α-氨基酸(AA)的质子化常数,Zn(Ⅱ)、Cd(Ⅱ)和Hg(Ⅱ)分别与PnAO和α-氨基酸二元体系的稳定常数以及Zn(Ⅱ)-、Cd(Ⅱ)-和Hg(Ⅱ)-PnAO-α-氨基酸三元体系的稳定常数.实验结果表明:在上述三元体系中均存在良好的直线自由能关系,并从三元配合物构型上讨论了存在线性关系的原因.发现标题体系的稳定性趋势为Zn(Ⅱ)>Cd(Ⅱ)<Hg(Ⅱ),并从金属离子的角度讨论了这种趋势的内在原因.

关键词: ⅡB族金属离子, &alpha, -氨基酸, 二酮肟配体, 稳定性

Abstract: The protonation constants of 3,3,9,9-tetramethyl-4,8-diazaundecane-2,10-dioxime(PnAO) and six α-amino acids, the stability constants of Zn(Ⅱ), Cd(Ⅱ), Hg(Ⅱ) PnAO, Zn(Ⅱ), Cd(Ⅱ), Hg(Ⅱ)-α-amino acids binary complexes and Zn(Ⅱ), Cd(Ⅱ), Hg(Ⅱ)-PnAO-α-amino acids ternary complexes have been determined by pHtitration method at (35±0.1) ℃, I =0.1 mol/L KNO3. The results show that the Linear Free Energy Relationship(LFER) has been found to exist between the protonation constants of α-amino acids and the corresponding stability constants of Zn(Ⅱ), Cd(Ⅱ), Hg(Ⅱ) PnAO-α-amino acids ternary system. The cause of existence of LFERhas been discussed by means of the stereo structures of the ternary complexes. The trend of change of the stability for the title systems is governed by the sequence Zn(Ⅱ)>Cd(Ⅱ)<Hg(Ⅱ), and the internal cause has been discussed in terms of the charge/radius effect and ionization potential of the metal ions.

Key words: Group ⅡB metal ion, α-Amino acids, Diketooxime ligand, Stability

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