4,4-Diaminobiphenyl reacts with 2,4-pentanedione in absolute ethanol in a molar ratio 1 : 2 to form mainly the product of [1 + 2] condensation, 4,4-(biphenyl-4,4-diyldinitrilo)dipentan-2-one (H 2 L). The Schiff base was used as tetradentate chelating ligand to coordinate Co II and Ni II chlorides leading to complexes where the ratio of metal ligand was found to be 2 : 1 or 2 : 2. All the synthesized products were characterized by elemental analysis, infrared, electronic, and mass spectroscopy, 1 H NMR, and DSC. The electrochemical behaviour of the ligand and its complexes in DMF is also investigated.