Zhai Chunguang, Yin Xiu, Niu Shifeng, Yao Mingguang, Hu Shuhe, Dong Jiajun, Shang Yuchen, Wang Zhigang, Li Quanjun, Sundqvist Bertil, Liu Bingbing
State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, China.
Institute of Atomic and Molecular Physics, Jilin University, Changchun, China.
Nat Commun. 2021 Jul 2;12(1):4084. doi: 10.1038/s41467-021-24381-5.
Developing a universal strategy to design piezochromic luminescent materials with desirable properties remains challenging. Here, we report that insertion of a non-emissive molecule into a donor (perylene) and acceptor (1,2,4,5-tetracyanobezene) binary cocrystal can realize fine manipulation of intermolecular interactions between perylene and 1,2,4,5-tetracyanobezene (TCNB) for desirable piezochromic luminescent properties. A continuous pressure-induced emission enhancement up to 3 GPa and a blue shift from 655 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-shifting hydrogen 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.
开发一种通用策略来设计具有理想性能的压致变色发光材料仍然具有挑战性。在此，我们报告将一种非发光分子插入供体（苝）和受体（1,2,4,5 - 四氰基苯）二元共晶体中，可以实现对苝与1,2,4,5 - 四氰基苯（TCNB）之间分子间相互作用的精细调控，从而获得理想的压致变色发光性能。在苝 - TCNB共晶体中插入四氢呋喃（THF）后，观察到在高达3 GPa的连续压力下发射增强，并且发射峰从655 nm蓝移至619 nm，这与压缩苝 - TCNB共晶体以及之前报道的其他共晶体时观察到的红移和发射猝灭形成对比。通过将实验与理论相结合，进一步揭示插入的非发光THF与相邻的TCNB分子形成蓝移氢键，并在压缩时促进苝分子的构象变化，导致发射蓝移和增强。当将其他分子作为非发光组分插入苝 - TCNB共晶体中以实现异常的压致变色发光行为时，该策略仍然有效。
