Synthesis and optoelectronic investigation of triarylamines based on imidazoanthraquinone as donor–acceptors for n-type materials

Abstract

A series of five new donor–acceptor molecules based on imidazo-anthraquinone-amines have been synthesized and characterized. The structure-property relationship in these molecules is systematically examined by absorption-emission spectroscopy, cyclic voltammetry and theoretical studies. Optical properties of these molecules have been studied in solvents of varying polarity as well as in neat solid film and found to be affected by the nature of triarylamine substituent with broad absorption windows, strong charge transfer transitions (425–502 nm), high molar extinction coefficients and emission in green light (500–568 nm). Electrochemical data indicated that the dyes possess relatively low-lying LUMO values ( $$-3.18$$ to $$-3.42$$ eV) while TGA studies revealed good thermal stability. The donor-acceptor architecture and HOMO–LUMO energies were further rationalized using DFT calculations. Experimental studies along with theoretical calculations suggest that these compounds have potential to be used as n-type materials in optoelectronic devices. Imidazoanthraquinone–amine derivatives with donor–acceptor molecular architecture were synthesized using Buchwald–Hartwig amination reaction featuring ICT absorption and low lying LUMO energy level ( $$-3.18$$ to $$-3.42$$ eV). These are comparable with well-known n-type materials for their applications in organic electronics.