Photoactivation of Solid‐State Fluorescence through Controllable Intermolecular [2+2] Photodimerization

Abstract

AbstractIntermolecular [2+2] photodimerization provides a distinctive approach to construct photoresponsive fluorescent materials in a manner of switching on solid‐state fluorescence. Herein, we report efficient photoactivation of bright solid‐state fluorescence based on controllable intermolecular [2+2] photodimerization reaction of benzo[b]thiophene 1,1‐dioxide (BTO) derivatives, which provides a simple and effective way to construct smart photoresponsive solid‐state fluorescent materials. Rational choice of substituents in BTO molecular skeleton enables them to efficiently undergo photodimerization through regulating molecular stacking in crystal, and also leads to photoactivation of solid‐state fluorescence due to the generation of brightly fluorescent photodimers. This intermolecular photodimerization reaction also offers an effective method to synthesize photostable AIEgens with purely through‐space conjugation.