Both monoanionic dicarbene pincer chelate and dianionic azole-pyridine-carbazole cyclometalate were successfully employed in the preparation of respective bis-tridentate Ir(III) metal complexes (Cz6–9) in moderate yields. Tuning of emission to blue was achieved by the addition of dual methoxy substituents at the carbazole cyclometalate, as well as the introduction of either methoxy or dimethylamino group at the central pyridinyl fragment of the azole-pyridine-carbazole cyclometalate. Single-crystal X-ray diffraction study was conducted on complex Cz6 in an attempt to provide an unambiguous structural proof. Photophysical properties were next measured in degassed CH₂Cl₂ solution at RT, giving structureless emission with peak maximum spanning 460–508 nm and photoluminescence quantum yield of 22–87%. A TD-DFT calculation confirmed the dominance of azole-pyridine-carbazole cyclometalate in controlling the emission energy gap, while the carbene pincer was less influential on the detected emission peak wavelength, i.e. acted as an ancillary. Importantly, the experimentally detected radiative lifetime (e.g. 2.78–17.18 μs) showed a clear correlation to the calculated metal-to-ligand charge transfer percentage of the electronic transitions (10.8–7.5%). Organic light-emitting diode devices gave turn-on voltages of 4.3 and 4.3 V, maximum EQE = 16.3 and 12.2%, power efficiencies of 17.6 and 10.4 lm W⁻¹ and with CIEx,y coordinates of (0.16, 0.26) and (0.16, 0.20) for Cz6 and 7 at 15 wt%, confirming their potential as blue dopants for phosphorescent organic light-emitting diodes.

中文翻译：

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甲氧基取代的双三齿铱（III）荧光粉和蓝色有机发光二极管的制造

单阴离子二卡宾钳形螯合物和双阴离子唑-吡啶-咔唑环金属盐均已成功地用于制备中等收率的双三齿Ir（III）金属配合物（Cz6-9）。通过在咔唑环金属化物上添加双甲氧基取代基，以及在吡咯-吡啶-咔唑环金属化物的中心吡啶基片段上引入甲氧基或二甲基氨基基团，实现了发射至蓝色的调谐。为了提供明确的结构证明，对复合物Cz6进行了单晶X射线衍射研究。接下来在脱气的CH ₂ Cl _2中测量光物理性质在室温下，可以得到无结构发射，最大峰跨度为460–508 nm，光致发光的量子产率为22–87％。TD-DFT计算证实了吡咯-吡啶-咔唑环金属盐在控制发射能隙方面的优势，而卡宾钳对检测到的发射峰波长的影响较小，即起辅助作用。重要的是，实验检测到的辐射寿命（例如2.78–17.18μs）与计算出的电子跃迁的金属-配体电荷转移百分比（10.8–7.5％）具有明显的相关性。有机发光二极管器件的开启电压为4.3和4.3 V，最大EQE = 16.3和12.2％，功率效率为17.6和10.4 lm W ^-1，CIE为x对于15重量％的Cz6和7，y坐标为（0.16，0.26）和（0.16，0.20），证实了它们作为磷光有机发光二极管的蓝色掺杂剂的潜力。