化学学报 ›› 1988, Vol. 46 ›› Issue (8): 808-811. 上一篇    下一篇

研究论文

配合物的稳定性与配位体碱强度之间的直线自由能关系 X.铜(II)-乙酰甘氨酸-α-氨基酸三元配合物竞争体系

陈荣悌;林华宽   

  1. 南开大学化学系
  • 发布日期:1988-08-15

Linear free energy relationships between stability of complex compounds and strengths of acid and base of ligands X. The copper(II)-N-acetylglycine-α-amino acid competitive ternary systems

CHEN RONGTI;LIN HUAKUAN   

  • Published:1988-08-15

报道了铜(II)-乙酰甘氨酸-α-氨基酸三元配合物体系的直线自由能关系. 以研究竞争性三元混配型配合物稳定性. 为认识生物体内所进行的生化反应的实质、用pH法测定了铜(II)-乙酰甘氨酸-α-氨基酸的竞争三元配合物的络合物生成常数.此处应用的α-氨基酸为L-脯氨酸, D,L-α-氨基异丁酸, L-异亮氨酸, L-缬氨酸,甘氨酸、L-丝氨酸、L-苏氨酸, 结果发现, 三元混配合物的稳定性与α-氨基酸的碱性强度间以及与原来的二元络合物间存在有线性自由能关系.

关键词: 氨基酸, 稳定性, 数据处理, 计算方法, 三元体系, 铜络合物, 三元络合物, 甘氨酸, 离解平衡, 酸碱平衡

The formation constants of the competitive ternary mixed-ligand complex compounds Cu(II)-N-acetylglycine-a-amino acids were determine by pH method at 25?in the presence of 0.1 mol/dm3 NaClO4. The a-amino acids used were L-proline, D,L-a-aminoisobutyric acid, L-isoleucine, L-valine, glycine, L-serine, L-threonine. Linear free energy relationships exist between the stability of the ternary mixed ligand complex compounds and the base strengths of the a-amino acids and with the stability of the parent binary complex compounds as well. The relevant correlation expressions are as follows: log b111 = 6.79 + 0.391pK2, r = 0.980; log b111 = 0.931 + 1.176 log b101, r = 0.999; log b111 = 2.06 + 0.565 log b102, r = 0.997, where b111 is the overall stability constant of the ternary complex compounds, b101 and b102 are the overall stability constants of the parent binary complex compounds, pk2 is the dissociation constant of the amino acid.

Key words: AMINO ACID, STABILITY, DATA HANDLING, COMPUTATIONAL METHOD, TERNARY SYSTEM, COPPER COMPLEX, TERNARY COMPLEX, GLYCINE, DISSOCIATION EQUILIBRIUM, ACID-BASE EQUILIBRIUM

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