Synthesis, crystal structure, spectroscopic and superoxide dismutase activity of copper(II) and nickel(II) complex of N '-[phenyl(pyridin-2-yl)methylidene]benzohydrazone

Abstract

Two binary copper(II) and nickel(II) complexes viz., [Cu(L)(HL)]NO₃.H₂O (<b style="mso-bidi-font-weight:normal">1</b>)<b style="mso-bidi-font-weight: normal"> </b>and [Ni(L)(HL)]NO₃.H₂O (<b style="mso-bidi-font-weight: normal">2</b>)<b style="mso-bidi-font-weight:normal"> </b>of hydrazone Schiff base ligand (where L/HL = <i>N</i>'-[phenyl(pyridin-2-yl)methylidene]benzohydrazone) have been synthesized and characterized. Both the complexes (<b style="mso-bidi-font-weight:normal">1</b>) and (<b style="mso-bidi-font-weight: normal">2</b>) and ligand (HL) are structurally characterized using single crystal X-ray diffraction technique. They crystallize in monoclinic crystal system in the space group <i style="mso-bidi-font-style:normal">P2₁/n</i>. The observed trends in spin-Hamiltonian parameters <i style="mso-bidi-font-style: normal">g</i>_║><i style="mso-bidi-font-style:normal">g</i>_┴>2.03 indicates a <i style="mso-bidi-font-style:normal">d</i>_x2-y2 ground state in complex (<b style="mso-bidi-font-weight: normal">1</b>). In<b style="mso-bidi-font-weight:normal"> </b>the absorption spectra in 100% DMSO, complex (<b style="mso-bidi-font-weight:normal">2</b>)<b style="mso-bidi-font-weight:normal"> </b>exhibits a <i style="mso-bidi-font-style: normal">d</i>-<i style="mso-bidi-font-style:normal">d</i> transition at ~900 nm, which is assigned to ν₁ band (³<i style="mso-bidi-font-style: normal">A</i>_2g→³<i style="mso-bidi-font-style:normal">T</i>_2g in octahedral parentage). Superoxide dismutase activities of both complexes reveal the dismutation of superoxide (O^2-).