Estudo de síntese, coordenação e propriedade antitumoral de complexos de níquel (II) e ligante oxalato

Abstract

In this study the optimization of syntheses was carried out, such as: in open atmosphere: at room temperature and under heating, at reflux and by microwaves at the times of: 30 s, 1 min, 2 min and 3 min, for the complexation of the following compounds: [Ni(ox)3]4-, [Ni(N3)2(ox)2]4-, [NiBr2(ox)2]4-, [Ni(ox)2(SCN)2]4- and [NiCl2(ox)2]4-. The complexed compounds were identified by the vibrational absorption spectroscopy in the infrared region. It was inferred that the coordination of the nickel(II) complexes was coordinated to the oxalate binders in a chelating way, distinctly coordinated azide binders, and for the syntheses carried out at ambient temperature and under heating, the nitrogen atom was coordinated in a terminal manner (N-terminal) and for the syntheses performed under reflux and by microwaves, the coordination occurred in a bridge by a nitrogen atom. For the thiocyanate ligand the coordination was by an N-terminal nitrogen atom and the oxalate ligand was coordinated in a chelating way, which suggests compounds of octahedral geometry. The verification of antitumor properties of the same against normal human pulmonary fibroblast (MRC-5) and human lung adenocarcinoma (A549) cell lines and cytotoxicity was verified fluorometrically by the resazurin reduction assay. The tests indicated lower cytotoxicity of the complexes when compared to the reference substance. Thus, it was possible to conclude that the proposed syntheses were successfully obtained, especially to the syntheses performed by microwave, since it allowed to obtain the complexes in a lesser period of time than the others and in front of the biological data obtained, it was noticed that the compounds obtained are promising as potential antitumor agents.