A hydrazone oxime (H2L) has been prepared in EtOH by reacting 2-hydrazine hydrate (2) with 2,3-butanedione monoxime (1). Homodinuclear copper(II), nickel(II), homotetranuclear copper(II), and heterotetranuclear copper(II)–nickel(II) complexes of H2L have been prepared. The metal complexes have been characterized by elemental analyses, magnetic moments, infrared (IR), ultraviolet–visible (UV-vis), and mass and thermal analyses studies. The dinuclear copper(II) and nickel(II) complexes of H2L were found to have a 1:1 metal:ligand ratio. In addition, total energy and heat formation for ligands (H2L and DHyLH2) by semiempirical PM3 calculations have shown that H2L is more stable than DHyLH2. [ABSTRACT FROM AUTHOR]