Transition metal complexes with thiosemicarbazide-based ligand – PartLV: Synthesis and X-ray structural study of novel Ni(II) complexeswith pyridoxal semicarbazone and pyridoxal thiosemicarbazone

Reaction of aqueous solutions of Ni(NO3)2 and pyridoxal semicarbazone (PLSC) in the presence of NaN3 afforded two complexes, viz. green, paramagnetic binuclear octahedral [Ni-2,(PLSC)2(41,,-N-3)2(N-3)(2)] 2H(2)O (1) and, as admixture, red, octahedral [Ni(PLSCH)21 - 2H(2),O (2) complex. Under the same reaction conditions, pyridoxal thiosemicarbazone (PLTSC) gave only one diamagnetic square-planar, red complex (Ni(PLTSC-H)N-3]center dot H,0 (3). In the absence of NaN3, the reaction of PLTSC and Ni(NO3)2 yielded brown paramagnetic octahedral complex [Ni(PLTSC)21(NO3)2 - H2O (4). The complexes were characterized by elemental analysis, conductometric and magnetochemical measurements, IR and UV-Vis spectra, and the octahedral complexes 1, 2 and 4 also by X-ray monocrystal diffraction method