Phase and Coordination Equilibria in Three-Component Systems of the Type MBn-r Pyridine-}-Chlorobenzene (M = Mn, Co, Ni, Cu and Zn)

Abstract

Solubility isotherms for MnBr2, CoBr2, NiBr2, CuBr2 and ZnBr2 in pyridine + chlorobenzene mixtures of varying composition have been determined at 20 and 30°C. Changes in the visible spectra of CoBr2, NiBr2 and CuBr2 with varying solvent composition have been followed. The results are analysed in terms of the nature of the solution complexes, their solvent-dependent activity coefficients and relative stabilities. The activity coefficients are found to be different functions of solvent composition for the [MBr2py2] and [MBr2py4] types of complexes but to a good approximation are independent of the nature of the central metal atom.