基于不同辅助配体的氟代二苯基苯并咪唑铱配合物的合成及溶液加工型电致发光器件

以氟代二苯基苯并咪唑为主配体,结合不同的辅助配体乙酰丙酮(对应配合物Ir-1a～Ir-3a)、2-吡啶甲酸(对应配合物Ir-1b～Ir-3b)和2-(5-三氟甲基-2H-1,2,4]三唑-3-基)-吡啶(tftp,对应配合物Ir-1c～Ir-3c),设计并合成了9个新颖的苯并咪唑铱(Ⅲ)配合物Ir-1a～Ir-3c....

Synthesis of Fluorinated Diphenylbenzimidazole Iridium Complexes Based on Different Auxiliary Ligands and Solution-Processed Electroluminescent Devices

Nine benzimidazole-iridium(Ⅲ) complexes Ir-1a-Ir-3c were designed and synthesized by using fluorinated diphenylbenzimidazole derivatives as the main ligands and acetylacetone(corresponding complexes:Ir-1a-Ir-3a),2-pyridine carboxylic acid(corresponding complexes:Ir-1b-Ir-3b),and 2-(5-trifluoromethyl-2 H-1,2,4]triazol-3-yl)-pyridine(tftp,corresponding complexes:Ir-1c-Ir-3c) as the auxiliary ligands,respectively.The effects of the degree of fluorination and different auxiliary ligands on the photophysical properties of the corresponding iridium complexes were investigated.The maximum emission wavelengths of the nine complexes were located in a range of 487-502 nm,showing green to blue-green phosphorescent emission.The largest blue shift was observed for the complexes based on tftp as an auxiliary ligand,especially for Ir-1c compared to Ir-1a with a blue shift of 17 nm.The nine complexes showed excellent photoluminescence efficiencies of 52%-87%.Furthermore,all iridium(Ⅲ) complexes exhibited good thermal stability,and the thermal decomposition temperatures were 313-390℃(5% weight loss).Four iridium complexes of Ir-1c,Ir-2c,Ir-3c,and Ir-2b were selected for spin-coated electroluminescent devices with a doping concentration of 9%.The results show that the change of the primary and secondary ligands has a large effect on the luminescent color and luminescent efficiency of the light-emitting diodes.The Ir-3c-doped spin-coated devices had the highest device efficiency with an external quantum efficiency of 10.2%,a current efficiency of up to 30.3 cd·A^-1,and a maximum power efficiency of 14.7 lm·W^-1.