The crystal structure of a new symmetrical pentadentate N 2 O 3 Schiff base: di[4-(phenylimino)pentan-2-one] ether (H 2 L) is described. In the solid state, the ligand appears as a keto-imine tautomer, while in DMSO solution, the eneamine form is observed. This ligand coordinates cobalt(II), nickel(II), copper(II) and cadmium(II). The structures of these new complexes are described using infrared and electronic spectroscopy, 1 H-n.m.r. and d.s.c. The cyclic voltammograms of the ligand and the complexes in DMF are discussed.