N1苯环醚键链接菲并咪唑类材料的制备及表征

在菲并咪唑(PI)类分子结构-性能研究的基础上, 保持C2苯环取代基不变, 在N1苯环处通过醚键偶联2个1,2-二苯基菲并咪唑(PPI)得到化合物ONBPPI结构, 并采用核磁共振波谱对其化学结构进行了确认. 对PPI及ONBPPI的热失重和差热扫描分析结果表明, 分子量的增加明显强化了分子的热学性能; 原子力显微镜扫描显示, ONBPPI在热退火过程中具有更好的热学薄膜稳定性. 单分子荧光光谱分析显示, PPI和ONBPPI的跃迁过程基本相似; 聚集态下, 醚键效应导致荧光光谱主峰位蓝移, 虽然在低能量处出现了光谱展宽现象, 但未影响到化合物固态蓝光的色纯度. 这些结果说明N1苯环醚键取代可在基本保持单臂PPI类结构光学性质的前提下, 实现热学、 形态学及其它功能的显著提高.

Preparation and Characterization of Phenanthroimidazole-based Derivatives with Ether Linkage at N1-Phenyl†

1,2-Diphenyl-1H-phenanthro[9,10-d]imidazole(PPI), as a model compound for PI-based compound in optoelectronic researches, exhibits good deep-blue emission with high color purity in solid, but has too bad thermal ability to apply as an emitter because its film would break under annealing. Based on the structure-property relationship of PI block, the newborn structure ONBPPI was prepared and confirmed by NMR spectra. It had the same substituted group at C2-position to PPI, and was introduced the ether linkage at N1-phenyl which was different to PPI at N1-position. The analysis of TGA and DSC showed that the thermal ability was enhanced accompany with the molecular weight increase from PPI to ONBPPI. AFM graphs showed that the film of ONBPPI had better stability than PPI in annealing at 90 ℃ for 2 h. And the similar fluorescence spectra in single molecular with fine split delivered that the unchanged transition process existed in both. In the film, a little blue-shift was observed in ONBPPI, which implied that the aggregation effect was weakened because of the ether bond insert. The phenomenon of the proportion of low-energy level emission increase in solid fluorescence spectra was found, but there was no obvious effect on deep-blue color. All of these results were consisted with our expected, and this strategy of enhancing multi-functions on PPI was realized under unchanged transition process by inserting ether linkage at N1-phenyl.