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化学学报
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化学学报 ›› 1993, Vol. 51 ›› Issue (7): 646-651. 上一篇    下一篇

研究论文

溶液中非过渡金属混合配体配合物形成的热力学研究2:某些镉(Ⅱ)-联吡啶(邻菲咯啉)-氨基酸混配配合物中配体间疏水缔合作用的热力学

高恩君;王魁;刘祁涛   

  1. 沈阳化工学院精细化工系;辽阳石油化工专科学校化工系;辽宁大学化学系
  • 发布日期:1993-07-15

Thermodynamical study on theformation of some mixed ligand complexes of non-transition metal ions in solution pt. 2:thermodynamics of hy drophobic interaction between ligands in some cadmium (Ⅱ)-2,2'-bipyridyl(1,10- phenanthroline)-aminoacids ternary com

GAO ENJUN;WANG KUI;LIU QITAO   

  • Published:1993-07-15

PDF

354

被引次数

33

应用pH电位法测定水溶液中CdLA型混合配体配合物和相应的单配体配合物CdL,CdL~2,CdA,CdA~2在离子强度为(0.10(KNO~3)、温度分别为15℃, 25℃, 35℃和45℃时的稳定常数,其中L为联吡啶或邻菲咯啉;A为丙氨酸、亮氨酸、苯丙氨酸和色氨酸,稳定性数据结合配体的结构表明,在含有亮氨酸、苯丙氨酸和色氨酸的混配配合物中存在着按上述配体顺序逐渐增强的配合物分子内的配体间疏水缔合作用.用温度系数法求出上述混配配合物形成反应的焓变ΔH,并进一步求出反应的自由能变化ΔG 和熵变ΔS.热力学函数数据表明,较大的熵增加是上述混配配合物中配体间疏水缔合作用的主要推动力.

关键词: 氨基酸, 色氨酸, 亮氨酸, 苯丙氨酸, 热力学函数, 丙氨酸, 二氮杂菲 P, 联吡啶 P, 镉络合物

The stability constants of the complexes of type CdA, CdA2, CdL and CdL2, and the mixed-ligands complexes of type CdLA were studied by potentiometric pH titration technique at ionic strength I = 0.10 (KNO3) at temperature 15, 25, 35 and 45? resp., (where L = 2, 2'-bipyridyl (bipy), or 1,10-phenanthroline (phen); A = alanine (ala), leucine (leu), phenylalanine (phe), and tryptophan (trp). The thermodn. functions for the reactions of formation were calculated by the temperature coefficient method. The results show that the hydrophobic interaction between ligands obviously presents in those ternary complexes containing leu., phe. and trp., and gradually intensifies along this order, and that the principal driving force of the hydrophobic interaction more entropy than enthalpy dependent.

Key words: AMINO ACID, TRYPTOPHAN, LEUCINE, PHENYLALANINE, THERMODYNAMIC FUNCTION, ALANINE, PHENANTHROLINE P, BIPYRIDINE P, CADMIUM COMPLEX

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