Synthesis and Structural Characterization of a Nickel(II) Complex with Unsymmetrical NNO-Donor Schiff Base Like Hydrazone Ligand

[[abstract]]The nickel(II) complex Ni[C5H4N–C(CH3)=N–N=C(O)–C6H5]2 (1), containing the potentially tridentate Schiff base like hydrazone ligand (LH) which is the 1:1 condensation product of benzhydrazide and 2-acetylpyridine, was prepared and characterized by IR and UV–Vis spectra, thermal analysis and single crystal X-ray diffraction measurements. Structural investigation shows that the molecule prefers a monoclinic lattice, having space group Cc, a = 10.248(6), b = 19.692(11), c = 12.281(7) Å, β = 91.523(10)º, Z = 4. The central Ni atom is in N4O2 coordination sphere developed with the NNO donor sets of the two independently Schiff base like hydrazone ligands with the two Ni–N(pyridine) bonds being significantly longer than the two Ni–N(imino) bonds, 2.096(6), 2.105(6) versus 1.972(6), 2.008(6) Å. The two Ni(II) amide-O bond distances of the chelating ligands are 2.090(6) and 2.092(6) Å respectively