一种基于三氟甲基取代的2-苯并[b]噻吩基吡啶配体的红色电致磷光材料及器件

研究了一种新型红色磷光材料及其在有机电致磷光器件(OLEDs)中应用.在经典红色磷光材料btp₂Ir(acac)的配体2-苯并噻吩吡啶的吡啶环的5位引入吸电子基团CF₃,将辅助配体换为2-吡啶甲酸,成功研制出了双(2-(2′-苯并b]噻吩基)吡啶)吡啶甲酸合铱配合物(btfmp)₂Ir(pic)].这种结构可以改变了原配合物的电子云分布,三氟甲基的引入将导致原分子的LUMO能下降,减小了HOMO与LUMO的能隙,引起发光峰位的红移,但2-吡啶甲酸又可引起发光蓝移,最终得到了最大峰位为637nm的饱和红光新的铱(Ⅲ)配合物,为通过简单配体修饰设计和制备新的有机磷光材料提供了一种简洁途径.

A New Iridium Complex with Trifluoromethyl-Substituted 2-benzo[b]thiophen-2-yl-pyridine Ligand and Its Application in OLEDs

By introducing a trifluoromethyl group on 5-position of the pyridyl ring of 2-benzob]thiophen-2-yl-pyridine, a new red emission iridium complex (btfmp)2Ir(pic)] using pyridyl-2-carboxylic acid as ancilary ligand was synthesized and characterized. We observed that a CF3 substituent on the 5-position of the ligand can decrease in the bandgap between the HOMO and LUMO levels, so as to result in large red shift of the emission band, but pyridyl-2-carboxylic acid acted as the ancilary ligand lead to emission shifting to blue. As a result saturated red light emitting EL based on red emission at 637 nm from the iridium complex was observed, a peak luminance efficiency of 3.0 cd/A, and the CIE color coordinates of (x=0.65, y=0.29) which are almost not changed under the varied driving current were obtained.