An ionic transition-metal complex for improved charge transporting properties was designed, containing both n-type dimesitylboryl (BMes2) and p-type carbazole groups. The complex, [Ir(Bpq)2(CzbpyCz)]PF6 (1) (Bpq = 2-[4-(dimesitylboryl)phenyl] quinoline, CzbpyCz = 5,5â²-bis(9-hexyl-9H-carbazol-3-yl)-2,2â²-bipyridine) and its equivalent in which the BMes2 groups were substituted with carbazole moieties were evaluated on the photoluminescence and excited state properties in detail. According to the photophysical and electrochemical properties, we concluded that the BMes2 groups can increase the conjugation length of the cyclometalated C^N ligands and greatly enhance the phosphorescence efficiency over the carbazole groups. In addition, the bulky BMes2 groups are effective in preventing the molecular aggregation in film. Both complexes were used to prepare single component light-emitting electrochemical cells (LECs). The electroluminescent devices show the typical behavior of LECs. The LEC based on the complex containing both electron- and hole-transporting groups shows the best performance. This work demonstrated that the design and synthesis of pân metallophosphors will be beneficial for the improvement of device performances.
我们设计了一种离子型过渡
金属配合物,它同时含有 n 型二甲基二巯基(BMes2)和 p 型
咔唑基团,可改善电荷传输特性。研究人员详细评估了[Ir(Bpq)2(CzbpyCz)]PF6 (1) 复合物(Bpq = 2-[4-(二甲基二
硼烷基)苯基]
喹啉,CzbpyCz = 5,5â²-双(9-己基-9H-
咔唑-3-基)-2,2â²-联
吡啶)及其等价物(其中 BMes2 基团被
咔唑基团取代)的光致发光和激发态特性。根据光物理和电
化学特性,我们得出结论:与
咔唑基团相比,BMes2 基团可以增加环甲基化 C^N
配体的共轭长度,大大提高
磷光效率。此外,笨重的 BMes2 基团还能有效防止分子在薄膜中聚集。这两种复合物都被用于制备单组分发光电
化学电池(L
ECs)。电致发光器件显示出 L
EC 的典型特性。基于同时含有电子和空穴传输基团的复合物的 L
EC 表现出最佳性能。这项工作表明,设计和合成pân
金属
磷酸盐将有利于提高器件的性能。