溶液中铅(Ⅱ)的某些氮杂芳香碱配合物形成的热力学研究

Thermodynamic Study on the Complex Formation of Lead(Ⅱ)with Bipyridyl and Phenanthroline in Solution

本文用 pH-电位滴定法在以 KNO_3为支持电解质、离子强度为0.1 mol/dm^3,温度为15,25,35和45℃条件下,测定了Pb(Ⅱ)的α,α′-联吡啶(bipy)和邻二氮菲(phen)配合物的稳定常数.应用温度系数法求出了各配合物形成反应的热力学函数变化.着重讨论了配体的碱性与配合物稳定性的关系.

The stability constants of the complexes Pb(Ⅱ)with bipyridyl(bipy)and phenanthro- line(phen)were determined potentiometrieally at 15,25,35,and 45℃ with an ionic strength of 0. 10 mol·dm^(-3)(KNO_3)in solution.The variation of thermodynamic func- tions of the formation reaction of abovementioned complexes were obtained by tempera- ture coeffient method.It was justified that there were linear free energy relation between the stability of the complexes and the base strength of the ligands.Finally,the driving force for the complex formation has also been discussed briefly.