两种新型芴衍生物的合成、晶体结构及光谱性能

合成了两种新型芴衍生物:2，7-二（3，5-二（三氟甲基）苯基）-9，9-二乙基芴（1）和2，7-二（4-氟苯基）-9，9-二乙基芴（2）。通过元素分析、红外光谱（IR）、核磁共振氢谱（¹H NMR）以及单晶X射线衍射对其结构进行了表征。化合物1属于单斜晶系，P2₁/c空间群;化合物2属于三斜晶系，P-1空间群。通过紫外-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CH₂Cl₂溶液和固态薄膜中，化合物1、2在350～400 nm波段有吸收峰，归属于π-π^*电荷跃迁;化合物1、2的光学带隙E_g分别为3.31 eV和3.30 eV，并且均有强烈的蓝色荧光发射现象（激发波长为330 nm），在二氯甲烷中的荧光量子效率分别为0.62和0.61，固态荧光寿命分别为6.39 ns和9.00 ns。

Synthesis,Crystal Structure and Spectroscopic Properties of Two Fluorene-based Derivatives

Two new types of fluorene derivatives, 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9-diethyl fluorene (C₃₃H₂₂F₁₂, M_r=646.51, compound 1) and 2,7-bis(4-fluorophenyl)-9,9-diethyl fluorene (C₂₉H₂₄F₂, M_r=410.48, compound 2) were synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 belonged to monoclinic crystal system, space group P21/c, and compound 2 was of triclinic with space group P-1. Their optoelectric properties were measured by UV-Vis absorption spectra and fluorescence spectra. The results show that compound 1 and 2 have low-energy absorption bands ranging from 350 nm to 400 nm in dichloromethane solution or solid film, which can be assigned to the π-π^* charge transfer transitions. The optical band gaps (E_g) of 1 and 2 are estimated to be 3.31 eV and 3.30 eV, respectively. The title compounds exhibite strong blue photoluminescence under 330 nm excitation at room temperature. The fluorescence quantum yields in CH₂Cl₂ of compound 1 and 2 are 0.62 and 0.61, and solid-state lifetimes are 6.39 ns and 9.00 ns, respectively.