2-(((4-(Trifluoromethyl)quinolin-6-yl)amino)methyl)phenols: Synthesis, optical properties, thermal, and electrochemical behavior

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 453; p. 115614
• Main Authors: Rocha, Inaiá O., Ketzer, Alex, Luz, Fábio M., Vieira, Jean C.B., Frizzo, Clarissa P., Martins, Marcos A.P., Zanatta, Nilo, Iglesias, Bernardo A., Bonacorso, Helio G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-08-2024
• Subjects: Aminophenols; Electrochemical; Photoluminescence; Quinolines; TD-DFT calculation; Quinolines; TD-DFT calculation; Aminophenols; Photoluminescence; Electrochemical
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2024.115614

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•Novel substituted 2-(((quinolinyl)amino)methyl)phenols are investigated.•Full structural characterization by NMR, FTIR, TGA, DFT, HRMS is performed.•Solution/solid-state photo properties (UV–Vis) and redox behavior are studied.•The photophysics of imine precursors and resulting aminophenols is evaluated.•High thermal stability greater than 200 °C by TGA experiments is verified.
This paper describes the synthesis, photophysical properties, and thermal and redox behavior of a novel series of nine selected 2-(((2-substituted-4-(trifluoromethyl)quinolin-6-yl)amino)methyl)phenols (4). These phenols contain 2-Me, 2-aryl, or 2-(2-furyl)-quinolines and 5-OMe, 4-Br or 4-NO2 substituted amino methylphenol cores assembled in the scaffolds of 4. Optimized yields of 51–98 % were obtained when the reactions of the respective imines 3 were conducted with sodium borohydride in ethanol at 80 °C for 30 min. The structural characterization of compounds 4 was performed by multinuclear NMR, FTIR, and HRMS techniques. Thermogravimetric analysis experiments indicated that the majority of the compounds obtained exhibited high thermal stability at temperatures over 200 °C. The UV–Vis steady-state and time-resolved fluorescence emission, TD-DFT calculations, and redox analyses were used to determine the photophysical and electrochemical properties of the studied derivatives, revealing a correlation between the electronic effects of the substituents attached to the quinoline and phenol cores and the evaluated parameters.