Synthesis and spectral characterisation of hydrazone based 14-membered octaaza macrocyclic Ni(II) complexes

Schiff base condensation of benzil bis(hydrazone) with formaldehyde, acetone and benzaldehyde and its nickel(II) complexes were synthesised. Preparation of the free ligands was accomplished by refluxing benzil with hydrazine derivatives in 1:10 mole ratios in ethylene glycol. The spectral characterisation of hydrazone based 14-membered octaaza macrocyclic complexes of nickel(II) was undertaken. The ligand, benzil bis(hydrazone) and complexes were characterized by FTIR, UV-visible, 1H NMR, Mass spectroscopy. The results of the investigations support the formulation of each of the complexes as a metal ion surrounded by a planar, quadradentate ligand. Thus, the data provide strong support for the conclusion that the macrocyclic complexes were actually prepared.