Nickel(II) complex with (E)-4-(4-methoxyphenyl)-2-(2-(2-pyridylmethylidene)hydrazinyl)thiazole:synthesis, characterization and antiproliferative activity

Abstract

(1,3-Thiazol-2-yl)hydrazones are known to have significant biological activity [1]. This property can be enhanced if these compounds are used as ligands in transition metal complexes. A complex of Ni(II) with (E)-4-(4-methoxyphenyl)-2-(2-(2-pyridylmethylidene)hydrazinyl)thiazole (HL) was synthesized from Ni(ClO4)2×6H2O and methanol solution of the ligand. Its crystal structure was determined by X-ray structural analysis. The complex was characterized by IR and UV/Vis spectroscopy, magnetic and conductivity measurements. It was found that the complex has general formula [Ni(HL)2](ClO4)2 and a distorted octahedral geometry, with the ligand tridentately coordinated through the imine, pyridine and thiazole nitrogen atoms in neutral form (Fig. 1). In vitro antiproliferative activity of the ligand and Ni(II) complex was evaluated against six human solid tumor cell lines. The activity of the complex was comparable or even better than that of the positive control 5-fluorouracil, the blockbuster anticancer drug.