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

Abstract

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.