Polymorphism-dependent mechanochromic luminescence in a donor–acceptor compound

Abstract

A mechanochromic luminogen material, MC-TPA, was synthesized, and two crystals (type Y and type O) exhibiting different fluorescence emissions were obtained through crystallization. Following mechanical grinding, type Y displayed red-shifted emission. Upon exposure to different solvent vapors, the amorphous phase selectively transformed into type Y or type O, respectively. Structural and theoretical analyses indicate that the divergent luminescence properties were governed by distinct packing modes and intermolecular interactions.