1′-Phthalazine hydrazone of diacetyl monooxime and its complexes with transition metals: Physicochemical and theoretical study

1′-Phthalazine hydrazone of diacetyl monooxime and its Cu(II) and Ni(II) complexes were synthesized. The acid-base properties of the hydrazone were potentiometrically and spectrophotometrically studied, and quantum-chemical calculations of the ionization constants and the energies of possible tautomeric forms and conformations were performed. Complexes of copper(II) prepared by the reaction of the hydrazone with copper(II) acetate, chloride, and bromide were shown to have the dimeric structure with the bidentatebridging N-O-groups of the oxime fragment, whereas the copper(II) complex prepared from copper(II) nitrate, forms the dimer via the endocyclic nitrogen atoms of the phthalazine fragment.