溶液中镉（Ⅱ）与某些氨基酸配合物稳定性的研究

Study on the stability of ternary complexec of Cadmium(Ⅱ)with some aminoacid in salution

用ｐＨ－电位滴定法测定了镉（Ⅱ）与某些氨基酸（其中包括丙氨酸（ａｌａ￣－）、亮氨酸（ｌｅｕ￣－）、色氨酸（ｔｒｙ￣－）、苯丙氨酸（ｐｈｅ￣－）配合物在离子强度Ｉ＝０．１０（ＫＮＯ＿３）、温度为１５℃、２５℃、３５℃和４５℃条件下的１、２级稳定常数，用温度系数法求出了配合物形成反应的热力学焓变ΔＨ，并进而求出了相应的自由能变化ΔＧ和熵变ΔＳ，发现配合物的稳定性与氨基酸配体的碱性强度之间存在直线自由能关系。

By using pHmethod,the first and second stepwise stability contants of ternary complexes ofCadmium with some aminoacids,ala. leu.try and phe. were determined at temperature 15,25,35. 45℃and ionic strength,I=0. 1(KNO_3)The variation of thermodynamie funetions of abovementioned complexes were obtalned by temperature ceeffient method,From the results same linear freeenergy relationships are found between the stability of the ternary compelexes and the base strengthsof abovenamed aminoaeids.