Study of Ternary Complexes of Bivalent Metal Ions with Dipyridyl and -Diketones: Investigation of Ternary Complexes of Bivalent Metal Ions

Abstract

Dipyridyl functions as a typical bidentate chelating agent through the N-atoms with the formation of a five-membered ring Figure 1The metal ion chelates of dipyridyl are formed at low pH values and these remain stable at high pH also. So, dipyridyl has been used as a primary ligand in the formation of mixed ligand complexes. The lowering of the potentiometric curve for the mixed system in comparison to the curve for binary complex of the metal with the primary ligand indicates the formation of a mixed ligand complex.The mixed ligand complexes of bivalent metal ions using dipyridyl as the primary ligand and -diketones (p-Bromobenzoylacetone and p-Chlorobenzoylacetone) as the secondary ligands. The stability constants for these systems have been determined potentiometrically. The competition of these ligands in the inner sphere of the bivalent ions has been studied by calculating the reproportionation constants.