Regularities in the distribution of metal complexes using 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (BMPP) as chelating ligand

The distribution ciefficients of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (BMPP) and its metal chelates with Co(II). Zn(II) and Eu(III) were determined between an aqueous acetate phase (μ=0.1) and eight ‘inert’ organic solvents at 25°C. On the basis of regular solution theory, the correlation between the distribution coefficients of the ligand (P_HA) and that of the metal chelate (P_M) vas found to be valid satisfactorily in most of the systems. The correlation between the distribution coefficient of the ligand and the solubility parameter of the solvent has been found to conform to regular solution theory.