Nanocomplexos de európio com mesoiônicos 1,3-tiazólio-5-tiolato e bipiridina: avaliação estrutural, térmica e espectrométrica.

Abstract

The study of nanomaterials has become a very important line of research in areas such as solid state physics, solid state chemistry, materials engineering, medical sciences and biotechnology. Research involving the coordination of lanthanide ions are gaining more prominence in science, because their luminescent properties. Conco mitantly, we highlight the scientific study of organic compounds that exhibit biological properties, among which we distinguish the mesoionic compounds that have structural features that have attracted considerable interest from researchers involved in the field of Medicinal Chemistry. In this sense, the ability to coordinate and link the properties of lanthanide ions with mesoionic compounds, in order to preserve the structural characteristics of these have attracted the attention of researchers. In this perspective, the present study aimed to synthesize crystalline powders of europium lanthanide ion coordination with the group mesoionic 1,3-thiazolium -5-thiolate and bipyridine, besides characterizing the complex I (MESO1) 3bipy and I (MESO2) 3bipy 2 - (4-chlorophenyl)-3-methyl-4-(4-methylphenyl) -1,3-thiazolium -5-thiolate (MESO1) and 2 - (4-chlorophenyl)-3-methyl-4-phenyl- 1,3-thiazolium -5-thiolate (MESO2) and 2,2-bipyridine (bipy). Leaving the reaction between europium chloride with organic ligands under reflux for about six hours as the mesoionics second linker, under magnetic stirring and temperature of 60 º C, was obtained a crystalline powder reddish. The results of melting / decomposition of binders compared to the complexes were quite different, indicating the formation of new substances. The nanocomplexos of lantadínicos ions showed satisfactory results of elemental analysis, confirming the stoichiometry (1:3:1). The absorption spectra in the UVvisible region showed displacement and the appearance of new bands, confirming coordination. The coordination of the ligands with landanídicos ions occurred through the exocyclic sulfur atoms (CS-) of mesoionics and nitrogen atoms (CN) of bipyridine observed in the infrared spectra. Emission spectra of the complexes show that the issue was not potentiated by cation. The results of x-ray diffraction patterns of the complexes show the disappearance and appearance of new peaks and the intensity variation. The micrographs confirmed the formation of the complexes and clusters showed the crystallinity of the compounds. Based on the thermogravimetric curves, the decomposition temperatures, among the synthesized complexes, I (MeSO2) 3bipy showed higher thermal stability. The DSC curves of the complexes show a shift of the peaks suggestive of the formation of new species.