A comparative study of the fluorescence properties of vinyl-bridging anthracene and/or phenanthrene isomers

作者：Li, Ye-Xin^*; Yang, Xiao-Feng; Cui, Yu; Nie, Yong; Wang, Fang-Fang; Sun, Guo-Xin

来源：Journal of Luminescence, 2017, 187: 14-19.

DOI：10.1016/j.jlumin.2017.02.057

• Isomer
• Aggregation-induced emission
• J-aggregation
• Crystal structure
• Polymorphism
• Crystal phase transition

We studied and compared the photophysical and aggregation-induced emission properties of three isomers: trans-1,2-di(9-anthryl)ethylene (DAE), trans-1-(9-anthryl) 2 (9 phenanthryl)ethylene (APE), and trans-1,2-di(9-phenanthryl)ethylene (DPE). Both DAE and APE molecules have a twisted conformation due to intramolecular H . . . H steric hindrance. By contrast, this kind of steric hindrance drastically decreases in DPE molecule. From DAE, APE, to DPE, there are a blue shift in the optical spectra and a marked increase in the fluorescence efficiency. Mainly due to the restriction of intramolecular rotation, DAE displays an aggregation-induced emission behavior. However, the fluorescence efficiency of APE decreases from solution to solid state. Different from DAE and APE, DPE is a dual-state highly efficient chromophore. The fluorescence efficiencies of its solution and the as-prepared powder (DPE-alpha) are 60% and 81%, respectively. J-aggregate was observed in the crystal structure of DPE-alpha, which correlates with its high emission efficiency. Interestingly, a new metastable polymorph of DPE was unexpectedly obtained by a solvent-antisolvent rapid precipitation. This new polymorph displays vapour and temperature-induced crystal-to-crystal phase transition and fluorochromism.

• 单位
  济南大学