Blue-emitting cationic iridium complexes with 2-(1H-pyrazol-1-yl)pyridine as the ancillary ligand for efficient light-emitting electrochemical cells
Blue-emitting cationic iridium complexes with 2-(1H-pyrazol-1-yl)pyridine as the ancillary ligand for efficient light-emitting electrochemical cells
复制标题
以 2-(1H-吡唑-1-基)吡啶为辅助配体的蓝色发射阳离子铱配合物用于高效发光电化学电池
DOI：
10.1002/adfm.200701505
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发表时间：
2008-07-23
影响因子：
19
通讯作者：
Qiu, Yong
中科院分区：
文献类型：
--
作者：
He, Lei;Duan, Lian;Qiu, Yong
合成了2-（1H-吡唑-1-基）吡啶（pzpy）为辅助配体的两种发蓝光的阳离子铱配合物[Ir（PPY）2（PZPY）1 PF 6和[Ir（dfPPY）2（PZPY）1 PF 6（ppy为2-苯基吡啶，dfppy为2-（2，4-二氟苯基）吡啶，PF 6为六氟磷酸根），并研究了它们的物理化学性质和电化学性质.在乙腈溶液中，[Ir（PPY）2（PZPY）] PF 6发射蓝绿光（475 nm），比典型的阳离子铱配合物[lr（ppy）2（dtb-bpy）] PF 6蓝移100 nm以上（dtb-bpy是4，4 ′-二叔丁基-2，2 ′-联吡啶）;具有氟取代的环化配体的[Ir（dfppY）2（PZPY）IPF 6显示出进一步的蓝移光发射（451 nm）。量子化学计算结果表明，这些发射主要来自环化配体（ppy或dfppy）的配体中心37r_7r * 态.当在[Ir（PPY）2（pzpy）] PF 6的发光层中加入离子液体1-丁基-3-甲基咪唑六氟磷酸盐时，可得到蓝绿色的电致发光（486 nm），并具有相对较高的发光效率（4.3 cd A-1）.基于[1. r（dfpPY）2（PZPYAPF 6）的LEC给出了具有CIE（Commission Internationale de L 'Eclairage）坐标为（0.20，0.28）的蓝色电致发光（460 nm），这是迄今为止报道的基于iTMC的LEC的最蓝光发射。我们的工作表明，使用含有供电子氮原子的二亚胺辅助配体（如PZPY）是将阳离子铱配合物的发光转向蓝色区域的有效策略。
Two blue-emitting cationic iridium complexes with 2-(IH-pyrazol-1-yl)pyridine (pzpy) as the ancillary ligands, namely, [lr(PPY)2(PZPY)1PF6 and [Ir(dfPPY)2(PZPY)JJPF6 (ppy is 2-ph enyl pyri dine, dfppy is 2-(2,4-difluorophenyl) pyridine, and PF6_ is hexafluorophosph ate), have been prepared, and their photophysical and electrochemical properties have been investigated. In CH3CN solutions, [Ir(PPY)2(PZPY)]PF6 emits blue-green light (475 nm), which is blue-shifted by more than 100 nm with respect to the typical cationic iridium complex [lr(ppy)2(dtb-bpy)]PF6 (dtb-bpy is 4,4'-di-tert-butyl-2,2'-bipyridine); [lr(dfppY)2(PZPY)IPF6 with fluorine-substituted cyclometalated ligands shows further blue-shifted light emission (451 nm). Quantum chemical calculations reveal that the emissions are mainly from the ligand-centered 3 7r_7r * states of the cyclometalated ligands (ppy or dfppy). Light-emitting electrochemical cells (LECs) based on [Ir(PPY)2(pzpy)]PF6 gave green-blue electroluminescence (486 nm) and had a relatively high efficiency of 4.3 cd A-' when an ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was added into the light-emitting layer. LECs based on [1.r(dfpPY)2(PZPYAPF6 gave blue electroluminescence (460 nm) with CIE (Commission Internationale de L'Eclairage) coordinates of (0.20, 0.28), which is the bluest light emission for iTMCs-based LECs reported so far. Our work suggests that using diimine ancillary ligands involving electron -donating nitrogen atoms (like pzpy) is an efficient strategy to turn the light emission of cationic iridium complexes to the blue region.