Li Hui, Han Jianhui, Zhao Huifang, Liu Xiaochun, Luo Yi, Shi Ying, Liu Cailong, Jin Mingxing, Ding Dajun
Institute of Atomic and Molecular Physics , Jilin University , Changchun 130012 , China.
Hefei National Laboratory for Physical Sciences at the Microscale , University of Science and Technology of China , Hefei , Anhui 230026 , China.
J Phys Chem Lett. 2019 Feb 21;10(4):748-753. doi: 10.1021/acs.jpclett.9b00026. Epub 2019 Feb 4.
The twisted intramolecular charge transfer (TICT) state plays an important role in determining the performance of optoelectronic devices. However, for some nonfluorescent TICT molecules, the "invisible" TICT state could only be visualized by modifying the molecular structure. Here, we introduce a new facile pressure-induced approach to light up the TICT state through the use of a pressure-related liquid-solid phase transition of the surrounding solvent. Combining ultrafast spectroscopy and quantum chemical calculations, it reveals that the "invisible" TICT state can emit fluorescence when the rotation of a donor group is restricted by the frozen acetonitrile solution. Furthermore, the TICT process can even be effectively regulated by the external pressure. Our study offers a unique strategy to achieve dual fluorescence behavior in charge transfer molecules and is of significance for optoelectronic and biomedical applications.
扭曲的分子内电荷转移（TICT）态在决定光电器件的性能方面起着重要作用。然而，对于一些非荧光TICT分子，“不可见”的TICT态只能通过修饰分子结构来可视化。在此，我们引入了一种新的简便的压力诱导方法，通过利用周围溶剂与压力相关的液-固相变来点亮TICT态。结合超快光谱和量子化学计算，结果表明，当供体基团的旋转受到冷冻乙腈溶液的限制时，“不可见”的TICT态可以发射荧光。此外，TICT过程甚至可以通过外部压力有效地调节。我们的研究提供了一种独特的策略来实现电荷转移分子中的双荧光行为，对光电子和生物医学应用具有重要意义。
