Estudos sobre a síntese e caracterização fotoquímica e fotofísica de derivados quinolínicos com estrutura doador-pi-aceptor, para utilização como corantes sensibilizadores de dispositivos eletrônicos orgânicos
Data
2019-09-20
Autores
Santos, Giovanny Carvalho dos
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Universidade Estadual Paulista (Unesp)
Resumo
Nas duas últimas décadas, muitos grupos de pesquisa têm concentrado seus esforços em otimizar os processos e materiais que constituem dispositivos eletrônicos orgânicos, entre eles as DSSCs (dye-sensitized solar cells – células solares sensibilizadas por corante). O desenvolvimento de novas estratégias sintéticas para uma eficiente produção de novos compostos orgânicos tem auxiliado nesses objetivos. Os derivados quinolínicos mostram uma variedade de aplicações em diversas áreas, assim neste trabalho foi estudada a síntese destes derivados com utilização do pentacloreto de nióbio, como ácido de Lewis, em reações multicomponentes entre derivados de anilina, derivados de aldeído e fenilacetileno. A partir dos derivados aminoquinolinicos obtibos, e através de uma segunda reação multicomponente na presença do NbCl5, benzaldeído e fenilacetileno, foram obtidos novos derivados antrazolínicos, uma classe de compostos que tem chamado a atenção por suas propriedades físicas e óticas. Essa metodologia mostrou melhores rendimentos e tempos reacionais comparados a outros métodos descritos na literatura. Ambos compostos, quinolinas e antrazolinas, possuem caracteristicas favoráveis para aplicação como corantes do tipo Doador-Pi-Aceptor, com potencial aplicação em dispositivos eletrônicos orgânicos, em especial as DSSCs. Foram sintetizados vários derivados quinolinicos e antrazolínicos, muitos destes inéditos na literatura, através de novas abordagens sintéticas como a síntese one-pot de aminoquinolínas. Estes derivados foram submetidos a análises de caracterização estrutural, fotoquímica e fotofísica, para que pudesse ser viabilizada sua aplicação. Medidas de absorção UV-Vis, Fluorescência, Voltametria Cíclica (VC) e Análise Termogravimétrica (TG) foram realizadas para conhecermos melhor as propriedades das moléculas sintetizadas. As moléculas sintetizadas foram estudas para diferentes áreas de aplicação (ex. Fotoiniciadores de polimerização, inibidores de corrosão, quimiossensores e sondas fluorescentes). Para termos um estudo mais detalhado e obtermos uma visão das estruturas eletrônicas dos compostos, os cálculos da DFT também foram realizados e mostraram boa correlação com o experimental. Foram alcançadas estruturas com propriedades interessantes, com absorção no visível (>400nm), alguns compostos com fluorescência no estado sólido, baixos bandgaps e termicamente estáveis, características estas que conferem uma ampla gama de aplicabilidade aos compostos sintetizados. Por fim alguns compostos foram utilizados como fotoiniciadores em reações de polimerização, alcançando ótimas conversões (> 61%) quando comparados aos padrões.
Over the past two decades, many research groups have focused their efforts on optimizing the processes and materials that constitute organic electronic devices, including dye-sensitized solar cells (DSSCs). The development of new synthetic strategies for the efficient production of new organic compounds has helped in these objectives. Quinoline derivatives show a variety of applications in several areas, so in this work, the synthesis of these derivatives using niobium pentachloride as Lewis acid was studied in multicomponent reactions between aniline derivatives, aldehyde derivatives and phenylacetylene. From the obtained aminoquinolinic derivatives, and by a second multicomponent reaction in the presence of NbCl5, benzaldehyde and phenylacetylene, new anthrazolinic derivatives were obtained, a class of compounds that has attracted attention for their physical and optical properties. This methodology showed better yields and reaction times compared to other methods described in the literature. Both compounds, quinolines and anthrazolines, have favorable characteristics for application as donor--acceptor dyes, with potential application in organic electronic devices, especially DSSCs. Several quinoline and anthrazoline derivatives have been synthesized, many of them unpublished in the literature and through new synthetic approaches, such as one-pot aminoquinoline synthesis. These derivatives were subjected to structural, photochemical and photophysical characterization analyzes, so that their application could be made possible. Measurements of UV-Vis absorption, Fluorescence, Cyclic Voltammetry (VC) and Thermogravimetric Analysis (TG) were performed to better understand the properties of the synthesized molecules. The synthesized molecules were studied for different application areas (eg. polymerization photoinitiators, corrosion inhibitors, chemosensors and fluorescent probes). In order to have a more detailed study and get an overview of the electronic structures of the compounds, the DFT calculations were also performed and showed a good correlation with the experimental one. Structures with interesting properties, with visible absorption (> 400nm) have been achieved, some compounds with solid state fluorescence, low bandgaps and thermally stable characteristics which give a wide range of applicability to the synthesized compounds. Finally some compounds were used as photoinitiators in polymerization reactions, achieving excellent conversions (> 61%) when compared to the standard
Over the past two decades, many research groups have focused their efforts on optimizing the processes and materials that constitute organic electronic devices, including dye-sensitized solar cells (DSSCs). The development of new synthetic strategies for the efficient production of new organic compounds has helped in these objectives. Quinoline derivatives show a variety of applications in several areas, so in this work, the synthesis of these derivatives using niobium pentachloride as Lewis acid was studied in multicomponent reactions between aniline derivatives, aldehyde derivatives and phenylacetylene. From the obtained aminoquinolinic derivatives, and by a second multicomponent reaction in the presence of NbCl5, benzaldehyde and phenylacetylene, new anthrazolinic derivatives were obtained, a class of compounds that has attracted attention for their physical and optical properties. This methodology showed better yields and reaction times compared to other methods described in the literature. Both compounds, quinolines and anthrazolines, have favorable characteristics for application as donor--acceptor dyes, with potential application in organic electronic devices, especially DSSCs. Several quinoline and anthrazoline derivatives have been synthesized, many of them unpublished in the literature and through new synthetic approaches, such as one-pot aminoquinoline synthesis. These derivatives were subjected to structural, photochemical and photophysical characterization analyzes, so that their application could be made possible. Measurements of UV-Vis absorption, Fluorescence, Cyclic Voltammetry (VC) and Thermogravimetric Analysis (TG) were performed to better understand the properties of the synthesized molecules. The synthesized molecules were studied for different application areas (eg. polymerization photoinitiators, corrosion inhibitors, chemosensors and fluorescent probes). In order to have a more detailed study and get an overview of the electronic structures of the compounds, the DFT calculations were also performed and showed a good correlation with the experimental one. Structures with interesting properties, with visible absorption (> 400nm) have been achieved, some compounds with solid state fluorescence, low bandgaps and thermally stable characteristics which give a wide range of applicability to the synthesized compounds. Finally some compounds were used as photoinitiators in polymerization reactions, achieving excellent conversions (> 61%) when compared to the standard
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Palavras-chave
Pentacloreto de nióbio, Reações multicomponentes, Derivados quinolínicos, Dispositivos eletrônicos orgânicos, Corantes sensibilizadores, Solvatocromismo