Institute of Organic Chemistry, Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland.
Istituto ISOF-CNR , Via P. Gobetti 101 , 40129 Bologna , Italy.
Org Lett. 2018 Jun 1;20(11):3183-3186. doi: 10.1021/acs.orglett.8b01011. Epub 2018 May 23.
Two hybrid dyes possessing tetraphenylethylene moieties weakly conjugated with a pyrrolo[3,2- b]pyrrole core have been synthesized. Both dyes display a weak emission in solution, however, in the solid state a ∼100-fold increase in the fluorescence quantum yield is observed. The position of the molecular rotors about the core greatly influences the photophysical characteristics. The variances in emission properties were assigned to entirely different changes in dihedral angles upon excitation, which in turn have substantial effects on radiative rate constants, allowed transitions, and HOMO/LUMO distribution.
两种具有弱共轭的四苯乙烯部分与吡咯并[3,2-b]吡咯核心的混合染料已被合成。这两种染料在溶液中均表现出较弱的发射，然而在固态下，荧光量子产率增加了约 100 倍。分子转子在核心周围的位置对光物理特性有很大影响。发射性质的差异归因于激发时二面角的完全不同变化，这反过来又对辐射速率常数、允许跃迁和 HOMO/LUMO 分布产生重大影响。
