金属离子副反应系数在配合物稳定常数测定中的直接应用

The direct application of metal ion side reaction coefficient in determining stability constants of coordination compound

提出了利用金属离子副反应系数直接用于测定配合物稳定常数的方法.即使用金属离子副反应系数对数值对自由配体浓度负对数作一阶微分图,找出曲线上r(L)=dlgαM(L)/dpL=-i(i为配离子配位数)对应的pL值,这些pL值处有lgαM(L)︱r(l)=i,=lgβi-ipLr(L)=-i-lgφGM,max,后者被用来测定配合物稳定常数.使用了2个配合物体系用于验证,它们相邻2级稳定常数对数值之差最小仅为0.42,计算结果与真值一致.

A new method for determining stability constants of coordination compound directly by metal ion side reaction coefficient was presented.Firstly,drawing the first-order differential diagram of logarithmic value of metal ion side reaction coefficient against the negative value of free ligand concentration.Secondly,finding these pLpoints which haver（L）=dlgαM（L）/dpL=-i（where i is the coordination number of coordination ion）.At these pL points,the coordination compound has equationslg lgαM（L）︱r（l）=i,=lgβi-ipLr（L）=-i-lgφGM,max.These equations were used for determining stability constants of coordination compound.The imaginary data of two coordination compound systems which the minimum difference of two successive logarithmic stability constants is 0.42 were used for calculation,and their results were the same as pre-set values.