Structural and spectral studies of nickel(II) complexes of di-2-pyridyl ketone N4, N4-(butane-1,4-diyl) thiosemicarbazone

An interesting series of three Ni(II) complexes with the general formula [NiLX] . 1/2 H2O (X = Cl, N-3 and NCS) were synthesized using di-2-pyridxl ketone N-4,N-4-(butane-1,4-diyl) thiosemicarbazone (HL). The structures of the compounds NiLCl (1) and NiL(N-3) (2) have been solved by single crystal X-ray crystallography with P (1) over bar and Pbca space groups, respectively. Electronic spectral data suggests a square planar geometry around nickel(II) in all the complexes. X-ray diffraction studies reveal that the thiosemicarbazone is bonded to the nickel(II) centre as an NNS donor ligand coordinating through one of the pyridine nitrogens, azomethine nitrogen and thiolate sulfur. Magnetic susceptibility measurements at room temperature indicate the diamagnetic nature of all the complexes. H-1 NMR, UV/Vis and IR spectroscopic data are consistent with the structures of compounds I and 2 derived from the crystallographic results and the spectral data for compound NiL(NCS) (3) suggest a structure similar to the chloro and azido derivatives. (C) 2004 Elsevier Ltd. All rights reserved.