Synthesis,spectral characterization and crystal structure of copper(II) complexes of 2-hydroxyacetophenone-N(4)-phenyl semicarbazone

Six new copper(II) complexes of 2-hydroxyacetophenone-N(4)-phenyl semicarbazone have been synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is inferred from IR spectra. Based on EPR studies, the spin Hamiltonian and bonding parameters have been calculated. The g   values, calculated for all the complexes in frozen DMF, indicate the presence of the unpaired electron in the d_x2-y2${\text{d}}_{x^2-y^2}$ orbital. The metal–ligand bonding parameters evaluated showed strong in-plane σ and in-plane π-bonding. The structure of the compound, CuLphen has been resolved using single crystal X-ray diffraction studies. The crystal structure revealed a monoclinic lattice with space group symmetry P2₁/c. The compound adopts a distorted square pyramidal geometry with a N₂O₂ core as the base.