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| Author(s): |
Bruno Henrique Sacoman Torquato da Silva
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Bauru. 2018-04-05. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru |
| Defense date: | 2018-02-23 |
| Advisor: | Luiz Carlos da Silva Filho |
| Abstract | |
The Friedel-Crafts acylation reaction is one of the most important reactions for the formation of carbon-carbon bonds. The Fridel-Crafts acylation reaction occurs basically by a reaction between aromatic compounds with acyl halides or anhydrides in the presence of a Lewis acid. Thus, in this work it was studied the use of niobium pentachloride as Lewis acid in Friedel-Crafts acylation reaction, aiming the synthesis of sensitizing dyes. The fluorescein derivatives were synthesized from phenolic derivatives and anhydride derivatives, in the presence of NbCl5 and under heating. The products of interest where obtained in yields of 54 to 90% and in short reaction times ranging from 50 to 200 minutes. The fluorescein derivatives presented absorption and emission within the range of visible and with high intensity and high fluorescence quantum yield (0,60 to 0,93) when dissolved in alkaline pH. Due to these good results obtained in the photophysical study, the fluorescein derivatives were applied in Gratzel solar cells, presenting convertion efficiencies that ranging from 0.11 to 0.23%. It has also been studied the application of fluorescein derivatives as initiator dyes in photopolymerization reactions of dimethacrylated resins. This resins have been widely used in dentistry, due this properties as, low toxicity, low solubility in water and high mechanical resistance. The fluoresceins promoted the photopolymerization of dimethacrylated resins with conversion values ranging from 1.21 to 78.7%, depending on the fluorescein derivative used as initiator dye. The NbCl5 also promoted the Friedel-Crafts acylation reaction of polycyclic aromatic hydrocarbon (PAHs). The best results were obtained for the acylation of truxene, with high yields (63 to 95%) and in short reaction times (30 to 100 min). The acylation reaction of decacyclene was obtained with 36% of yield and in 20 hours of reaction. However, the acylation reactions of the decaciclene and the graphite require additional studies to find the best synthetic conditions, since the products were obtained in low yields and long reaction times. Keywords: Friedel-Crafts acylation reaction; (AU) | |
| FAPESP's process: | 14/01337-1 - Studies about the use of Niobium pentachloride, as Lewis acid, in Friedel Crafts acylation reactions, aiming the synthesis of compounds with potential application as sensitized dyes in organic eletronic devices. |
| Grantee: | Bruno Henrique Sacoman Torquato da Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate |