溶液中钴（Ⅱ）、镍（Ⅲ）的某些三元配合物中的直线自由能关系

Linear Free Energy Relationship in some Ternary Complexes of Cobalt(Ⅱ)and Nickel(Ⅱ)

用ｐＨ－电位滴定法测定了三元配合物ＭＡＢ（其中Ｍ＝Ｃｏ￣（２＋）、Ｎｉ￣（２＋），Ａ为２，２＇－联吡啶（ｂｉｐｙ）、邻菲咯啉（ｐｈｅｎ），Ｂ为顺丁烯二酸根（ｍａｌｅ￣（２－））、丁二酸根（ｓｕｃｃ￣（２－））、邻苯二甲酸根（ｐｈｔｈ￣（２－））、４－硝基邻苯二甲酸根（ｎｐｈｔ￣（２－）））在２５℃、离子强度为０．１ｍｏｌ·ｄｍ￣（－３）（ＫＮＯ＿３）条件下的稳定常数、相应的二元配合物稳定常数和配体的质子化常数，实验结果表明，三元配合物的稳定常数与二元羧酸配体的碱性强度之间存在良好的线性关系．从配体间相互作用等方面对配合物的稳定性进行了讨论。

The stability constants of some ternary co mplexes MAB were determined by potentio-metric pH-titratlon technique at temperature 25℃and ionic strength I=0.1 mol·dm￣(-3)KNO_3(where M = Co￣(2+) or Ni￣(2+);A=2,2'-bipyridyl or 1,10-phenanthroline;B=maleate,succinate,phthalate and 4-nitrophthalate),the stability constants of binary complexes and protonatlon constants of corresponding ligands were also determined similarly.The results showed that some linear free energy relationships are found to exist between the stability constants of ternary complexes and base strengths of the dlcarboxyllc ligands. Considering the ligand-ligand interaction , the stability of ternary complexes was discussed.