Stacking-induced different performance of mechanochromic luminescence and room-temperature phosphorescence based on two analogous AIEgens synthesized by a green photo-oxidation reaction

Abstract

Novel smart materials that can achieve a diverse range of practical applications with simple molecular structures and green synthesis routes are still in great demand. Herein, by a green photo-oxidation reaction, two simple aggregation-induced emission luminogens (AIEgens) CZ-PYZ and p-CZ-BYZ were developed, with the difference of linking type between the donor group (carbazole) and the acceptor group (a benzoylimino derivative). These two analogues exhibited different luminescence behaviors in the aggregation state. The molecule p-CZ-BYZ showed mechanochromic luminescence and room-temperature phosphorescence simultaneously, while none of the similar phenomena was observed in the case of CZ-PYZ. According to photophysical property tests, single crystal structural analyses and theoretical calculations, we found that this difference was induced by their different stacking manners. It was believed that the present results may provide us with a better understanding of structure–property relationship and offer an important guideline for multifunctional molecular design.