含噁二唑四枝分子的合成与非线性吸收

选择噁二唑基团作为多枝化合物的“枝”,以苯甲腈基和咔唑基团为分子的“核”,合成了两个四枝化合物(BO-G2和NO-G2),进行了核磁共振和质谱的表征.从结构上看,BO-G2和NO-G2分别具有“D-A-A-’A-D”和“D-’A-D-A-D’”电荷转移特征,后者具有pn结.吸收光谱和荧光光谱证实,NO-G2具有较大的激发态和基态偶极矩差值,存在着明显的分子内电荷转移和非线性吸收.

Synthesis and Fluorescence Properties of Two Oxadiazole-Based Multibranched Chromophores

Two new multibranched chromophores,named as NO-G2 and BO-G2,with the same peripheral branch of oxadiazole-unit,but different molecular core,that is,carbazole for NO-G2 and benzonitrile for BO-G2,were synthesized and characterized by mass spectra and 1H NMR spectra,respectively.These two oxadiazole-based multibranched chromophores show the molecular architecture of "D-A-A'-A-D" for BO-G2 and"D'-A-D-A-D'"for NO-G2, which have the different ability of intramolecular charge transfer.The measured absorption and fluorescence spectra have shown that NO-G2 exhibits nonlinear absorption than BO-G2,owing to the former possessing pn junction and resultant more obvious intramolecular charge transfer.