Preparation and characterization of some ternary complexes of copper(II) with o-phenanthroline and oxygen donor ligands

A series of eight ternary complexes, viz. [Cu(phen)(acac)] Cl and Cu(phen)L(H2O)n(phen = o-phenanthroline; L = a bidentate oxygen donor ligand; n = 0, 1 or 2), have been prepared and characterized by microanalysis, infrared spectral and electronic spectral measurements. The results indicate that the Cu(phen)2+ species has a great affinity for oxygen donor ligands resulting in chelate rings of varying sizes. Infrared spectral data indicate that the Cu-O bond weakens as the oxygen donor chelate ring increases in size; the Cu-N bond appears to be less sensitive to ring size. Tentative assignments for the electronic absorption bands have also been made.