A new mathematical treatment of spectrophotometric data for differentiating mononuclear and polynuclear complexes

A new mathematical approach to the treatment of spectrophotometric data for differentiation between mononuclear and polynuclear metal complexes in solution is presented. The slope of a straight line yields the total number of units in the complex, from which the true molecular formula can be obtained if the empirical formula is known. The formation constant is also given by the slope of a straight line. The method can be applied to complexes with any number of different ligands. Solutions are prepared in which the ratio of total concentrations of the reacting species is equal to the combining ratio. Spectrophotometric data must be obtained under conditions where only one complex is formed and the degree of dissociation is significant. The molar absorptivity must be obtained by direct measurement.