Effect of Terminal Groups on Exciton Binding Energy in Tetraphenylethylene-based π-Conjugated Molecules

Exciton binding energy (Eb) is a key parameter governing photoinduced charge separation, and establishing molecular design strategies for reducing Eb remains an important challenge. To investigate the effect of terminal groups in π-conjugated compounds on the solid-state Eb, a series of tetraphenylethylene-based molecules bearing electron-accepting terminal groups with varied intermolecular interaction strengths were designed and synthesized. Experimental analyses revealed that molecules exhibiting stronger π–π stacking interactions show reduced Eb. Furthermore, to evaluate how this difference in molecular packing influence functional performance, we prepared Al₂O₃-supported photocatalysts and investigated their photocatalytic activities under light irradiation.