Four ionic orange phosphorescent iridium(III) complexes (Ir1, Ir2, Ir3, Ir4) were successfully synthesized using coumarin 6 as the cyclometalated ligand and 2,2′-bipyridine (bpy) derivatives with different number and position of methyl groups as the auxiliary ligand. The effects of substituents in the auxiliary ligands on their properties were systematically investigated. These four complexes exhibited orange emission at wavelengths of 590, 588, 587, and 586 nm, respectively, with excellent solubility and remarkable photophysical properties in different solvents. Furthermore, they were further applied in the organic light-emitting diodes (OLEDs) based on solution method. The maximum luminance of the devices based on Ir1/Ir2/Ir3/Ir4 reached 1907.0/932.6/760.8/519.3 cd/m, with corresponding maximum current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) values of 1.56/1.71/1.97/1.52 cd/A, 0.33/0.32/0.35/0.27 lm/W, and 0.77/0.82/0.90/0.72 %, respectively. Although there is room for improvement in the performance of OLEDs, this strategy inspires us to modulate the novel photoluminescent and electroluminescent properties of iridium(III) complexes through rational modifications of their ancillary ligands.

中文翻译：

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基于香豆素6为主配体的磷光铱(III)配合物的溶液加工橙色有机发光二极管

以香豆素6为环金属配体，不同甲基数量和位置的2,2′-联吡啶(bpy)衍生物为辅助，成功合成了四种离子橙色磷光铱(III)配合物(Ir1、Ir2、Ir3、Ir4)配体。系统研究了辅助配体中取代基对其性能的影响。这四种配合物分别在590、588、587和586 nm波长处表现出橙色发射，在不同溶剂中具有优异的溶解度和显着的光物理性质。此外，它们还进一步应用于基于溶液法的有机发光二极管（OLED）。基于Ir1/Ir2/Ir3/Ir4的器件最大亮度达到1907.0/932.6/760.8/519.3 cd/m，并具有相应的最大电流效率（CE）、功率效率（PE）和外量子效率（EQE）值分别为 1.56/1.71/1.97/1.52 cd/A、0.33/0.32/0.35/0.27 lm/W 和 0.77/0.82/0.90/0.72 %。尽管OLED的性能还有改进的空间，但这种策略启发我们通过对其辅助配体的合理修饰来调节铱（III）配合物的新型光致发光和电致发光特性。