高等学校化学学报

高等学校化学学报 ›› 1995, Vol. 16 ›› Issue (4): 495.

• 论文 •    下一篇

介质对配合物稳定性的影响(Ⅵ)──Fe(CTS)-NaClO4-C2HOH-H2O

刘魁道, 何成凤, 刘祁涛   

  1. 辽宁大学化学系, 沈阳 110036
  • 收稿日期:1994-04-18 修回日期:1994-11-10 出版日期:1995-04-24 发布日期:1995-04-24
  • 通讯作者: 刘魁道,男,56岁,副教授.
  • 作者简介:刘魁道,男,56岁,副教授.
  • 基金资助:

    国家自然科学基金

The Influence of Medium on the Stability of Coordination Compounds(Ⅵ)──The System of Fe (CTS)--NaClO4-C2H5OH-H2O

LIU Kui-Dao, HE Cheng-Feng, LIU Qi-Tao   

  1. Department of Chemistry, Liaoning University, Shenyang, 110036
  • Received:1994-04-18 Revised:1994-11-10 Online:1995-04-24 Published:1995-04-24

PDF (PC)

摘要： 用分光光度法在293±1K温度下测定了由高价阳离子Fe3+和高价阴离子(CTS)4-(3,6-二磺酸钠-1,8-二羟基萘酚)形成配阴离子Fe(CTS)-在乙醇-水混合溶剂中的稳定常数随离子强度的变化。用推广的Debye-Hckel方程和Pitzer方程计算了配位离子的热力学稳定常数,发现De-bye-Hckel方程完全不能适用本体系,而基于Pitzer方程的多项式逼近法则可得到满意的结果。讨论了介质效应和络合反应的标准迁移自由能。

关键词: 配合物的稳定性, Pitzer方程, 介质效应

Abstract: The stability of compfex anion Fe(CTS)--composed of cation Fe3+and anion (CTS)4-in mixed solvents of ethanol-water with weight percentage of ethanol 0, 10, 20,30,40 and 50 was measured spectrophotometrically at 293 ± 1 Kby using NaClO4 as the supporting electrolyte with ionic strength ranging from 0.1～3. 0 mol/L. The thermodynamic stability constants of Fe(CTS)-in various mixed solvents have been obtained by a polynomial approximation equation based on Pitzer's theory. As a comparison, the traditional De bye-Hckel equation was used to treat the same data. The results show that this polynomial approximate method is obviously superior to the Debye-Hckel equation. It was discovered that there is a linear relation between the thermodynamic stability constants of Fe(CTS)-and the mole fraction of organic component in mixed solvents or the reciprocal of dielectric constants of the solvents. The medium effect and the standard free energy of transfer for the coordination reaction:Fe3++(CTS)4-=Fe(CTS)-is also discussed.

Key words: Stability of complexes, Pitzer's equation, Medium effect

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