论文部分内容阅读
设计合成了一种基于苯并咪唑的新型双极性蓝色磷光主体材料1-苯基-2-[4-(N-咔唑基)苯基]苯并咪唑(PCPB),并对其结构进行了表征。通过紫外-可见、荧光、低温磷光光谱以及循环伏安法、热重分析、差热分析和密度泛函理论对其性能及结构进行了研究。结果表明,PCPB在CH2Cl2稀溶液中的吸收峰位于296和368 nm,发射峰位于401nm,属于深蓝色荧光;PCPB的低温(77K)磷光光谱的第一吸收峰位于452nm,其三线态能级为2.74e V,与蓝色磷光材料FIrpic(2.62e V)的能级相匹配;PCPB的HOMO主要分布在苯基咔唑单元,而LUMO主要定域在苯并咪唑环上。其HOMO能级为-5.54e V,与阳极ITO的功函(-4.5~-5.0 e V)相匹配,LUMO能级为-2.68e V,接近于电子传输材料PBD(-2.82e V)。PCPB表现出双极传导性能,且热稳定性良好。
A novel biphenyl blue phosphorescent host material based on benzimidazole (PCPB) was designed and synthesized. Its structure Characterized. Their properties and structures were studied by UV-vis, fluorescence, low-temperature phosphorescence and cyclic voltammetry, TG, DTA and DFT. The results showed that the absorption peak of PCPB in CH2Cl2 dilute solution was located at 296 and 368 nm and the emission peak was at 401 nm, which belonged to dark blue fluorescence. The first absorption peak of PCPB at low temperature (77K) was at 452 nm and the triplet energy level was 2.74e V, which matches the energy level of the blue phosphorescent FIrpic (2.62e V). The HOMO of PCPB mainly distributes on the phenylcarbazole unit while the LUMO is mainly localized on the benzimidazole ring. The HOMO level is -5.54eV, which matches the anode ITO’s work function (-4.5 ~ -5.0 eV). The LUMO energy level is -2.68eV, which is close to the electron transport material PBD (-2.82eV). PCPB exhibits bipolar conductivity and good thermal stability.