A series of novel diiridium complexes (1–4) bearing both functional 2‐pyrazolyl‐6‐phenyl pyridine chelate and bidentate phenyl imidazolylidene chelate are synthesized, for which the pyrazolate fragment of the tridentate 2‐pyrazolyl‐6‐phenyl pyridine also behaves as the bridge to hold two iridium atoms in close vicinity. Their structure is unambiguously confirmed using X‐ray structure determination on the corresponding derivative 2a bearing 1,3‐bis(4‐fluorophenyl)‐1H‐Imidazolyl cyclometalate. Their photophysical and electrochemical properties are studied and further affirmed by the computational approaches. All these Ir(III) metal complexes 1–4 are very stable in both solution and solid film with near unity emission quantum efficiency. As opposed to most of diiridium complexes documented in literature, 1–4 are volatile and suitable for fabrication of organic light emitting diodes (OLEDs) under vacuum evaporation. The corresponding electroluminescent devices exhibit superior performance, among which external quantum efficiency of 27.6% using 2 as dopant stands for the record high of OLEDs using dinuclear Ir(III) complexes. They also offer a low roll‐off at high luminance, demonstrating their potential en route to high performance OLEDs.

中文翻译：

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桥联吡唑鎓盐的发光二铱配合物：使用真空热沉积的OLED的表征和制备

一系列新颖的二铱配合物（1 - 4）轴承既实用2吡唑基-6-苯基吡啶螯合物和二齿苯基imidazolylidene螯合物被合成，为此，三齿2-吡唑基-6-苯基吡啶的吡片段还表现为该桥可将两个铱原子紧密结合在一起。通过对相应的带有1,3-双（4-氟苯基）-1H-咪唑基环金属酸盐的衍生物2a进行X射线结构测定，可以明确确定其结构。对它们的光物理和电化学性质进行了研究，并通过计算方法得到了进一步的证实。所有这些的Ir（III）的金属络合物1 - 4在溶液和固体膜中都非常稳定，并且具有接近统一的发射量子效率。相对于大多数在文献中记载的二铱络合物，1 - 4是易失性和适合于在真空下蒸发有机发光二极管（OLED）的制造。相应的电致发光器件表现出优异的性能，其中使用2作为掺杂剂的外部量子效率为27.6％，代表了使用双核Ir（III）配合物的OLED的创纪录高位。它们还提供了高亮度下的低滚降，证明了它们在高性能OLED途中的潜力。