Abstract
Developing a universal strategy to design new piezochromic luminescent materials with desirable properties remains challenging. Here, we report that insertion of a non-emissive molecule into a donor (perylene) and acceptor (TCNB) binary cocrystal can realize fine manipulation of intermolecular interactions between perylene and TCNB for desirable piezochromic luminescent properties. A continuous pressure-induced emission enhancement up to 3 GPa and a blue shift from 655 nm to 619 nm have been observed in perylene-TCNB cocrystals upon THF insertion, in contrast to the red-shifted and quenched emission observed when compressing perylene-TCNB cocrystals and other cocrystals reported earlier. By combining experiment with theory, it is further revealed that the inserted non-emissive THF forms blue-shifted H-bonds with neighboring TCNB molecules and promote a conformation change of perylene molecules upon compression, causing the blue-shifted and enhanced emission. This strategy remains valid when inserting other molecules as non-emissive component into perylene-TCNB cocrystals for abnormal piezochromic luminescent behaviors. Our strategy could also be extended to other cocrystals with different donor-acceptor components, opening a new way for designing novel piezochromic luminescent materials for future applications.
Pyrene-Fused Hexaarylbenzene Luminogens: Synthesis, Characterization, and Aggregation-Induced Emission Enhancement
