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.