基于三苯基-1,3,5-均三嗪的星形双极性蓝色磷光主体材料的合成及性质

Synthesis and Properties of Star Bipolar Blue Phosphorescent Host Materials Based on Triphenyl-1,3,5-s-Triazine

本工作设计、合成了两种基于三苯基-1,3,5-均三嗪的星形双极性蓝色磷光主体材料:((6-(3-(9-乙基-9H-咔唑-3-基)苯基)-1,3,5-三嗪-2,4-二基)双(3-苯基))双(二苯基氧化膦)(CzPTBPO)和(3-(4,6-二(3-(9-乙基-9H-咔唑-3-基)苯基)-1,3,5-三嗪-2-基)苯基)二苯基氧化膦(BCzPTPO)。CzPTBPO和BCzPTPO的荧光发射峰分别位于410nm和424nm处,属于深蓝色荧光;由低温磷光的第一发射峰计算得到它们的三线态能级(ET)分别为2.75eV和2.68eV,与蓝色磷光客体材料FIrpic(2.65eV)的能级相匹配;由循环伏安测试计算得到它们的HOMO能级分别为-5.68eV和-5.62eV,与阳极ITO的功函(-4.5^-5.0eV)相匹配,其LUMO能级分别为-2.42eV和-2.44eV,可与多数的电子传输材料匹配(如:TPBi为-2.70eV),且HOMO与LUMO轨道几乎没有重叠,表明其具有良好的空穴注入和电子传输的双极性质;TG显示两种材料的分解温度(5%质量损失)分别为398℃和387℃,表明其热稳定性非常好;DSC显示其玻璃化温度分别为148℃和134℃,表明其具有无定形态结构及良好的成膜性。因此,CzPTBPO和BCzPTPO有望作为双极性蓝色磷光主体材料应用于磷光有机发光二极管(PhOLEDs)。

Two star bipolar blue phosphorescent host materials with triphenyl-1,3,5-s-triazine as the core were designed and synthesized:((6-(3-(9-ethyl-9H-carbazol-3-yl)phenyl)-1,3,5-triazine-2,4-diyl)bis(3-phenyl)) bis(diphenylpho-sphine oxide)(CzPTBPO) and (3-(4,6-bis(3-(9-ethyl-9H-carbazol-3-yl)phenyl)-1,3,5-triazin-2-yl)phenyl)di-phenyl-phosphine oxide(BCzPTPO). The fluorescence emission peaks of CzPTBPO and BCzPTPO are located at 410 nm and 424 nm,respectively,which are dark blue fluorescence. As calculated from the first emission peak of low-temperature phosphorescence,the triplet level ( E T) is 2.75 eV and 2.68 eV,which matched with the energy level of blue phosphorescent guest material FIrpic (2.65 eV). The HOMO levels are calculated to be -5.68 eV and -5.62 eV,respectively,which match the function of the anode ITO (-4.5--5.0 eV),and the LUMO levels are -2.42 eV and -2.44 eV,respectively. It can be matched with most electron transport materials (such as TPBi is -2.70 eV),indicating that they have good bipolar properties of hole injection and electron transport. TG shows that the decomposition temperature (5% mass loss) is 398 ℃ and 387 ℃,respectively,indicating that the thermal stability is very good. DSC shows that the glass transition temperature is 148 ℃ and 134 ℃,respectively,indicating that it has an amorphous structure and good film-forming performance. Therefore,CzPTBPO and BCzPTPO are expected to be used as a bipolar blue phosphorescent host material in PhOLEDs.