【摘要】 运用密度泛涵理论B3LYP/6-31G(d)方法,优化了苯环上含氟和三氟甲基的1,3,4-噁二唑类化合物基态的几何构型,计算了它们相应的紫外吸收光谱。计算结果表明,紫外吸收光谱及分子轨道的能隙值与实验数据基本吻合;结果还显示,与不含氟的噁二唑化合物相比,三氟甲基和2,3,5,6-四氟苯单元都能降低化合物的LUMO与HOMO能级,但三氟甲基的影响明显大于2,3,5,6-四氟苯单基,并且三氟甲基使分子的能隙值增大,分子的吸收和发射光谱发生蓝移;而2,3,5,6-四氟苯基却使分子的能隙值降低,分子的吸收和发射光谱发生红移,得到与实验一致的结论。更多还原

【Abstract】 A density functional theory(DFT) at a B3LYP/6-31G(d) level was used to optimize the UV-Vis spectra of the 1,3,4-oxadiazoles containing 2,3,5,6-tetrafluorophenyl and trifluoromethylphenyl groups. The results showed that both trifluoromethylphenyl and 2,3,5,6-tetrafluorophenyl groups influenced the optical properties of the oxadiazoles. In comparison with the 1,3,4-oxadiazoles without fluoro group, trifluoromethylphenyl and 2,3,5,6-tetrafluorophenyl groups substituted 1,3,4-oxadiazoles exhibited lower LUMO and HOMO energy levels. Moreover, the influence of trifluoromethylphenyl group was larger than that of 2,3,5,6-fluorophenyl group. As a result, the oxadiazoles containing trifluoromethylphenyl and 2,3,5,6-tetrafluorophenyl groups showed a blue shift in their UV-Vis spectra, which matched well with the previously reported experimental results.更多还原