Cu(Ⅱ)-正己(辛)烷基亚氨二乙酸-氨基酸体系混配型配合物的研究

来源期刊：中南大学学报(自然科学版)1987年第3期

论文作者：杨天足 陈超球 张祥麟

文章页码：331 - 337

关键词：混合配体络合物； 三元络合物； 铜络合物； 亚胺基； 二元羧酸； 烷基； 氨基酸； 稳定带数； pH测定； 电位测定；正烷基亚氨二乙酸

Key words：mixed-ligand complex； ternary complex； copper complex； imino group； dicarboxylic acid； alkane； amino acid； stability constant； pH determination； potentiometric determination；n-alkyl iminodiacetic acid

摘    要：用pH电位法研究了Cu(Ⅱ)-正己(辛)烷基亚氨二乙酸(H₂A)-氨基酸(氨基乙酸、DL-α-氨基丙酸、DL-α一氨基丁酸、β一氨基丙酸或DL-β-氨基丁酸,统以HB表示)体系的混配型配合物。导出了第一配体(正己(辛)烷基亚氨二乙酸根离子)与Cu(Ⅱ)(1:1)配合完全的[H]计算式。在25±0.1℃,μ=0.1(KNO₃)的条件下,测定了该体系的混配型配合物的稳定常数。结果表明:IgK_CuAB与第一配体的关系不大,而主要与第二配体有关;IgK_CuAB与Igβ_CuB2存在线性关系。

Abstract: The mixed--ligand coordination compoundsin the systems of Cu (Ⅱ)--u--alkyl (hexyl or octyl) iminodiacetic acids (H₂A)--amino acids (glycine, DL--α--alanine, DL--α--amino--butyric acid, β--alanine or DL--β--amino--butyric acid) have been studied pH--potentiometrically. The formula for calculating the hydrogen ion concentration [H] at which the primary ligand, n-hexyl or n--octyl iminodiacetate ion, coordinates practically completely with Cu (Ⅱ) (1: 1) has been derived; it is [H]=1/(σ+1)-T_cu·K₁/σβ^H₁where T_Cu denotes the total concentration of Cu (Ⅱ), K_i, the stability constant of CuA and β₁^H the first protonation constant of A; σ==[CuA]/[Cu] (taken to be, say, 50).At the temperatuse t= 25±0. 1℃ and the ionic sttength μ= 0.1 (KNO₃), the stability constants K_CuAB of the mixed--ligand coordination compounds CuAB (B denotes one of the five amino-carboxylates) in these systems were determined. The vallles obtained are sumarized in the following table. Moreover, it has been found that there exists a linear relationship between lgK_CuAB and lgβ_cuB2 (β being the overall stability consant).