Desenvolvimento de hidrogéis superporosos contendo nanopartículas de cobre: potenciais catalisadores na síntese de 1,2,3-triazóis

Abstract

This dissertation is focused on the synthesis of a hydrogel based on chitosan and poly(vinyl alcohol) embedded with copper nanoparticles (labeled as QT/PVA- CuNP) to act as catalysts in the synthesis of 1,2,3-triazoles. Using different analytic characterization techniques it was demonstrated the hydrogel synthesis as well as entrapment of copper nanoparticles (CuNP) in the hydrogel matrix. Moreover, macro and microscopic analysis evidenced the formation of a hydrogel with high porosity (i.e. a superporous hydrogel). As assessed, the CuNP embedded in the QT/PVA matrix influenced several properties of the resulting material. Catalytic activity of the QT/PVA-CuNP superporous hydrogels was examined in the synthesis of 1,4-diphenyl-1H-1,2,3-triazole (3). From this reaction, it was found that the catalyzed reaction showed considerable triazole yield, which ranged from 50 to 92%. The phenylazides (1) and phenylacetylenes (2) were used as starting chemicals and a mixture of water and ethanol was used as the solvent. In addition, a series of additional 1,2,3-triazoles compounds were also synthesized using QT/PVA-CuNP as the catalyst. Reuse studies allow noticing that these original catalysts can be used for at least 5 consecutive reaction cycles. Therefore, the methodology described and rationalized in this dissertation showed was efficient in the synthesis of superporous hydrogels embedded with CuNP. Moreover, these CuNP-containing hydrogels presented remarked catalytic activity in the synthesis of 1,2,3-triazole.