Department of Chemistry and Biomolecular Sciences, University of Ottawa , 10 Marie Curie Pvt. Ottawa, Ontario K1N 6N5, Canada.
J Org Chem. 2017 Oct 20;82(20):11008-11020. doi: 10.1021/acs.joc.7b01972. Epub 2017 Oct 12.
A new class of push-pull fluorophores featuring the pentafluorosulfanyl (SF) group as a potent acceptor has been synthesized. Known for its excellent chemical and thermal stability, the unique SF functionality is also strongly electron-withdrawing but at the same time highly lipophilic. We report six new fluorescent dyes, which were characterized by UV-vis/fluorescence spectroscopy, single-crystal X-ray diffraction, and cyclic voltammetry. Notable dye properties include large Stokes shifts (>100 nm), pronounced solvatofluorochromic effects arising from intramolecular charge transfer, moderate fluorescence quantum yields in both solutions and thin films, and extensive supramolecular C-H···F interactions in their crystalline states. Reversible mechanofluorochromism was also observed in dye 5, where grinding and fuming of a solid sample gave blue- and red-shifted emissions, respectively. Postfunctionalization of dye 3 to afford a pair of strong visible-light absorbers was also demonstrated.
一类新型推拉型荧光染料已被合成,其特征是五氟硫基(SF)基团作为强吸电子基团。SF 基团以其优良的化学和热稳定性而闻名,同时具有很强的吸电子性,但又高度亲脂性。我们报道了六种新的荧光染料,通过紫外-可见/荧光光谱、单晶 X 射线衍射和循环伏安法对其进行了表征。显著的染料性质包括大斯托克斯位移(>100nm)、源于分子内电荷转移的显著溶剂化荧光变色效应、在溶液和薄膜中的中等荧光量子产率,以及在其晶体状态下广泛的超分子 C-H···F 相互作用。染料 5 还表现出可逆的机械荧光变色性,其中固体样品的研磨和冒烟分别导致蓝色和红色的发射峰位移。对染料 3 进行后官能化,得到一对强可见光吸收剂也得到了证明。