Tricarbazole-based donor–acceptor architectures with diverse acceptors: synthesis, properties and applications

Abstract

Herein, using tricarbazole as an electron donor and four aromatic rings with various electron cloud densities as acceptors, four homologous donor–acceptor (D–A) architectures (TrCzDAa∼d) were divergently synthesized and characterized. Their steady-state and transient photophysical properties were subsequently investigated, in which their intramolecular charge transfer transitions were disclosed by solvent-dependent fluorescence spectra. Interestingly, an electron-rich acceptor could result in a blue shift in fluorescence, while an electron-deficient acceptor led to red-shifted fluorescence emission. Furthermore, intense and stable electrochemiluminescence (ECL) signals were observed for all architectures. In contrast, the ECL intensity was enhanced with increasing electron cloud density of the acceptor. Finally, TrCzDAb, displaying optimal ECL performance, was used as an electrode modification material to construct an epinephrine sensor, which demonstrated high sensitivity, excellent stability, and remarkable selectivity. This work elucidated the regulatory role of the electron cloud density of the acceptor on the optoelectronic properties of D–A architectures and provides new insights for developing novel high-performance optoelectronic materials and sensors.