Photophysical properties of donor-acceptor antiaromatic organoboron compounds based on dithienodiborinines

Boron-containing antiaromatics, such as diborinines and boroles, have sparked interest in materials chemists owing to their exciting optical properties and high Lewis acidity. In this study, we synthesized donor-acceptor (D-A) type diborinines fused with thiophene rings by introducing electron-donating amino-substituted aryl groups onto boron and elucidated their properties. The D-A type dithienodiborinines exhibited long-wavelength absorption arising from their D-A interactions and antiaromaticity. In addition, their fluorescence intensity increased under oxygen-free conditions, indicating thermally activated delayed fluorescence. Graphical Abstract