Avaliação e Otimização da Verdura Química de Sínteses de Complexos

Abstract

In this thesis, a model for evaluating and optimizing the greenness of syntheses of coordination compounds was developed, aiming at its practice in the educational context. The greenness and the dangers of the substances involved in the synthesis of twenty-three complexes were analyzed. For this evaluation, the atomic mass metric, the green star holistic metric, and the SHE (safety, healty and environment) tool were used. The protocols were analyzed, and the various aspects and possibilities of greeness improvement were considered, resulting in the selection of three syntheses for optimization: i) cis-di(glycinate)copper(II); ii) potassium dioxalate cuprate(II) dihydrate; and iii) di(saccharinate)copper(II). For the selected syntheses, the greenness was evaluated (using a battery of mass metrics), the substance hazards were evaluated (using the SHE tool), the structural and morphological characterization (using different techniques, including X-Ray Diffraction (DRX), Fourier Transform Infrared Spectroscopy (FTIR), and Electronic Spectroscopy (UV-Vis) for solids), colorimetric analysis and the antibacterial activity of the complexes. It was possible to optimize the initial protocols for the three syntheses in the various aspects that were aimed at: increasing or maintaining the greenness, increasing or maintaining the synthesis yield, reducing the mass of solvents and improving up the mass metrics. The optimization of these syntheses showed the complexity and challenge inherent in the process of increasing the greenness of synthesis processes. No significant changes were observed in the diffractograms and spectra for the complexes synthesized in the original protocol and in the optimized protocols, that is, the optimization did not imply changes in the structures of these complexes. Regarding the antibacterial action, the disaccharinatecopper(II) complex was the only one that showed antibacterial activity for the two tested bacteria, being more effective for the S. aureous bacteria than for the E. coli bacteria.