Abstract:

       To avoid the complexity of existing stability constant determination methods for polynuclear complexes, we presented a new determination method by using the maximum distribution coefficients of polynuclear complex ions. This method works with simple principle and calculation, needs no programming, and can determine the stoichiometry of polynuclear complex ions existing in solution. We employed the firstorder partial differentials, logarithmic value of total metal concentration in solution against negative logarithmic values of free metal concentration and that against free ligand concentration, and the factor alternation method to obtain experimental conditions for determining the stability constant.Computational results of two polynuclear complexes, which were used to verify the acquired formula, are in accordance with real values.

Key words: polynuclear complex, stability constant, distribution coefficient, maximum, slope