Studies on the synthesis and photochemical and photophysical characterization of quinolinic derivatives with donor-pi-acceptor structure for use as dyes sensitizing in organic electronic devices

Author(s)

Giovanny Carvalho dos Santos

• Document type: Doctoral Thesis
• Press: Bauru. 2019-10-21.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru
• Defense date: 2019-09-20
• Advisor: Luiz Carlos da Silva Filho

Abstract

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 Several quinoline and anthrazoline derivatives have been synthesized, many of them unpublished in the literature and through new synthetic approaches, such as one-pot aminoquinoline synthesis.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 (AU)

• FAPESP's process: 15/00615-0 - Studies on the synthesis and photochemical and photophysical characterization of quinoline derivatives with donor-p-acceptor structure for use as sensitizing dyes in organic electronic devices
• Grantee: Giovanny Carvalho dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate