Síntese e caracterização de complexos de cobre (II) com ligantes vanilóides

Abstract

The objective of this work is to contribute to the development of coordination chemistry of copper-phenanthroline system, through the synthesis and characterization of new metal complexes of the type [Cu(phen)(L)2] where L refers to vanillin derivatives ligands. Through characterization of the complex [Cu(phen)(asv)2], [Cu(phen)(asvred)2] and [Cu(phen)(dhz)2], by infrared, it was identified that the binders derived from vanillin are coordinated to the metal center bidentately through the vanilloid groups and the phenanthroline is maintained in the coordinating sphere of the metal. The electron spectra of the complexes, obtained in acetonitrile, presented intraligant bands of phenanthroline with high molar absorptivity, intraligant bands typical of the vanilloid ligand L, with hypochromic and bathochromic displacements in relation to the uncoordinated ligand and also d-d transitions, which reaffirm the formation of the complex. The fluorescence identification of the ligand of the asv ligand was performed both in the solid state and in acetonitrile solution. The fluorescence spectrum of this compound had an emission band at 506 nm, which corresponds to the green color region, when excited in the ultraviolet region. The potential for reducing the Cu2+/1+ in the complex, [Cu(phen)(asv)2], [Cu(phen)(asvred)2] and [Cu(phen)(dhz)2], were observed, respectively, - 62, - 45 and - 126 mV vs. Ag / AgCl. The values obtained are in a potential range considered appropriate (261 to -523 mV) for the covers, when reduced to Cu1+, is capable of generating reactive oxygen species in a biological environment.