Integration of aggregation-induced emission and intramolecular charge transfer in a V-shaped organic donor-acceptor

Abstract

Coumarin, an oxadiazole, and the V-shaped structural characteristic of a sulfone have been integrated to create a new symmetric compound, and the compound was characterized. The synthesized molecule was used as an emitter and an electron transporter in three different device configurations. The sulfone units induced a V-shaped structure that weakened the π-π stacking and thus limited aggregation-induced quenching. The molecule emitted strong fluorescence in the amorphous solid state, in a membrane, and in a non-polar solvent. From thermogravimetry and differential scanning calorimetry, the compound shows good thermal stability (381 °C) and glass-transition temperature (125 °C). The solvatochromism phenomenon and electrochemical properties were investigated in detail by fluorescence spectroscopy and cyclic voltammetry. Time-dependent density functional theory calculations were performed to understand the photophysical properties. This new type of compound exhibits tunable light emission in solution, making it a versatile emitter.