硫砜类双极性蓝色磷光主体材料的合成及性能

摘要

设计并合成了一种基于硫砜类的双极性蓝色磷光主体材料2-(10H-吩噁嗪基)噻吨-9-酮-10,10-二氧化物(TXOPXZ),并用1HNMR、13 CNMR和元素分析对其结构进行了表征.通过紫外-可见(UV-Vis)、荧光、低温磷光、循环伏安法、热重分析(TGA)、差热分析(DSC)和密度泛函理论(DFT)对其性能和能级结构进行了研究.结果表明:TXOPXZ在二氯甲烷稀溶液中的最大吸收峰位于285 nm;发射峰位于439 nm;低温(77 K)磷光光谱的第一发射峰位于460nm,其三重态能级为2.70 eV,可与蓝色磷光材料FIrpic(2.62 eV)的能级匹配;循环伏安法测得TXOPXZ的HOMO能级为-5.28 eV,与阳极ITO的功函(-4.5～-5.0 eV)相匹配,LU-MO能级为-1.95 eV,与电子传输材料TAZ(-2.30 eV)的LUMO能级相匹配,表明TX-OPXZ具有良好的双极性能;TGA数据表明其分解温度为329℃,具有良好的热稳定性,DSC显示其Tg温度为191℃,表明其具有无定形结构和良好的成膜性.%A novel bipolar blue phosphorescent host material,2-(4 H-phenoxazin-10-yl)-4 H-thioxanthen-9 H-10,10-dioxide (TXOPXZ),was designed and synthesized,and its structure was characterized by means of 1 HNMR,13CNMR and elemental analysis.The photophysical properties and energy-level structure of TXOPXZ were studied by ultraviolet-visble (UV-Vis),fluorescence,phosphorescent spectroscopies at 77 K,cyclic voltammetry (CV),thermogravimetric analysis(TGA),differential scanning calorimetry (DSC) and density functional theory(DFT).The results show that the maximum absorption wavelength is located at about 285 nm in dilute CH2Cl2 solution.The emission peak of TXOPXZ is located at 439 nm in dilute CH2Cl2 solution,and exhibits blue phosphorescent emission at 460 nm from the highest-energy vibronic subband at 77 K,from which its triplet state energy (ET) is estimated to be 2.70 eV.TXOPXZ can be used as host material for the blue emitter Firpic(2.62 eV) in PhOLED.Cyclic voltammetry measurement shows that HOMO energy level of TXOPXZ is located in-5.28 eV,which match with the energy levels of ITO(-4.5～-5.0 eV);LUMO energy level of TXOPXZ is located in-1.95 eV,which is close to the energy level of TAZ(-2.30 eV).The TGA data showed that the decomposition temperature was 329 ℃,indicating good thermal stability.DSC showed that the Tg was 191 ℃,indicating amorphous structure and good film forming property.