一种基于D-π-A型芴衍生物的合成、核磁共振谱及光谱性能研究∗

摘要

A new type of fluorene derivative,2-(2,4-difluorophenyl)-7-(4-methoxyphenyl)-9,9-dioctylfluorene (compound 1)was synthesized and characterized by elemental analysis,IR spectra and NMR Spectroscopy.Its optoelectric properties were measured by UV-Vis absorption spectra and fluorescence spectra.The results show that compound 1 has low-energy absorption bands ranging from 350 nm to 400 nm in dichloromethane solution, which can be assigned to theπ-π∗ charge transfer transitions.The optical band gap (Eg )of compound 1 was estimated to be 3.39 eV.The title compound exhibits strong blue photoluminescence under 310 nm excitation at room temperature.The fluorescence quantum yields of compound 1 in CH2 Cl2 was up to 0.70.In addition,the wavelength of the absorption and emission spectra of compound 1 depend on the polarities of the solvents.%合成了一种具有 D-π-A 结构特征的新型芴衍生物：2-(2,4-二氟苯基)-7-(4-甲氧基苯基)-9,9-二辛基芴(1)。通过元素分析、红外光谱(IR)以及全面的一维核磁共振氢谱(1 H NMR )、碳谱(13 C{1 H}NMR)、氟谱(19 F{1 H}NMR)对其结构进行了全面表征。通过优化反应物的投料顺序,得到较为合理的合成方法。详细分析了核磁共振谱谱线特征。利用紫外-可见吸收和荧光光谱研究了化合物的发光性能。结果表明,在 CH2 Cl2溶液中,化合物1在300~330 nm波段有吸收峰,归属于π-π∗跃迁；其光学带隙Eg 为3.39 eV,发射峰值位于383 nm,并且具有强烈的深蓝色荧光发射(激发波长为310 nm),在CH2 Cl2溶液中量子效率达到0.70。此外,化合物1的吸收和发射光谱具有溶剂极性依耐性。