物理化学学报 >> 1994, Vol. 10 >> Issue (09): 785-789.doi: 10.3866/PKU.WHXB19940904

研究论文 上一篇    下一篇

氨三乙酸稀土络合物配体交换反应的NMR研究

任吉民, 景凤英, 裴奉奎, 王文韵, 倪嘉缵   

  1. 中国科学院长春应用化学研究所,长春 130022
  • 收稿日期:1993-04-02 修回日期:1993-07-31 发布日期:1994-09-15
  • 通讯作者: 裴奉奎

Ligand Exchange Reactions of Lanthanide Complexes with Nitrilotriacetate Ln(NTA)2 by 13C and 1H NMR

Ren Ji-Min, Jing Feng-Ying, Pei Feng-Kui, Wang Wen-Yun, Ni Jia-Zuan   

  1. Changchun Institute of Applied Chemistry,Changchun 130022
  • Received:1993-04-02 Revised:1993-07-31 Published:1994-09-15
  • Contact: Pei Feng-Kui

摘要:

利用变温13C、1H-NMR研究了过量配体存在下,氨三乙酸稀土络合物Ln(NTA)2(Ln=Ce,Pr和Nd)配体交换反应,在中性水溶液中,分子间的配体交换过程按如下机制进行:
Ln(NTA)23- ×H*NTA2-↔ Ln(*NTA)(NTA)3+ + HNTA2-
由溶液中自由NTA信号线宽分析了交换速率,确定了反应的活化能.结果表明,分子间配体交换反应的活化能与相应稀土络合物的热力学稳定性有一定关系.

关键词: 氨三乙酸, 核磁共振, 稀土络合物

Abstract:

 Ligand exchange reactions were studied by VT 13C and 1H NMR for lanthanide complexes with nitrilotriacetate Ln(NTA)2 in neutral aqueous solution in the presence of an excess of ligand (Ln=Ce, Pr and Nd). The intermolecular ligand exchange occurs by the following mechanism
Ln(NTA)23- ×H*NTA2-↔ Ln(*NTA)(NTA)3+ + HNTA2-
The exchange rates were analysed from the line-width values of free NTA and it is found that the activation energy values of the ligand exchange are related to the thermodynamic stability of the corresponding lanthanide complexes with NTA.

Key words: Nitrilotriacetate, Lanthanide cmplex, NMR