论文部分内容阅读
前文曾报导用离子选择电极研究铜(Ⅱ)-α-氨基酸体系的稳定常数logK_(CuL),但此法不能测定第二级稳定常数logK_(CuL_2)。为深入研究其线性热力学函数关系,本文用PH电位法测定铜(Ⅱ)-α-氨基酸体系配合物在25、35及45℃logK_(CuL)~t和logK_(CuL_2)并分别求得在上述温度时配合物的自由能变化(△G_(CuL)和G_(CuL_2))、生成焓(△H_(CuL)和△H_(CuL_2))及生成熵(△S_(CuL)和△S_(CuL_2))研究结果表明,上述氨基酸配合物(CuL和CuL_2)的稳定性与配位体碱性强度之间均成线性自由能关系;配合物的生成焓与配位体的加质子焓△H_L~之间也存在着线性关系。
Previously reported ion selective electrode copper (Ⅱ) -α-amino acid system stability constant logK_ (CuL), but this method can not determine the second level of stability constant logK_ (CuL_2). In order to further study the linear thermodynamic function, we determined the logK_ (CuL) ~ t and logK_ (CuL_2) of Cu (Ⅱ) -α-amino acid complexes at pH 25, (△ G_ (CuL) and G_ (CuL_2)), enthalpy of formation (ΔH_ (CuL) and ΔH_ (CuL_2)) and entropy generation of ΔS_ (CuL) and ΔS_ )) The results show that the stability of the amino acid complexes (CuL and CuL_2) and the ligand basic strength linear relationship between the free energy; complex formation enthalpy and ligand plus proton enthalpy △ H_L ~ There is also a linear relationship between.