Recyclable mechanoluminescent luminogen: different polymorphs, different self-assembly effects of the thiophene moiety and recovered molecular packing via simple thermal-treatment

Abstract

We report a purely organic recyclable mechanoluminescent luminogen (tPE-5-MeTh) with the combination of an AIEgen and a thiophene group as the self-assembly unit. As a result of the different self-assembly effects, two crystalline polymorphs were cultured from different solvents, which possess totally different packing modes and various inter/intramolecular interactions with opposite ML properties. Excitingly, the molecular packing status of tPE-5-MeTh could be adjusted through simple thermal-treatment, offering recoverability and controllability of its ML activity. These results provide a new avenue for rational molecular design, convenience of potential applications and deep understanding of the inherent mechanism.