Excited-State Lifetime Modulation by Twisted and Tilted Molecular Design in Carbene-Metal-Amide Photoemitters.
Excited-State Lifetime Modulation by Twisted and Tilted Molecular Design in Carbene-Metal-Amide Photoemitters.
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DOI：
10.1021/acs.chemmater.2c01938
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发表时间：
2022-08-23
影响因子：
8.6
通讯作者：
Romanov, Alexander S.
中科院分区：
文献类型：
--
作者：
Gu, Qinying;Chotard, Florian;Eng, Julien;Reponen, Antti-Pekka M.;Vitorica-Yrezabal, Inigo J.;Woodward, Adam W.;Penfold, Thomas J.;Credgington, Dan;Bochmann, Manfred;Romanov, Alexander S.
卡宾金属酰胺（CMA）是一类基于线性供体-连接体-受体排列的新型光发射体。它们对卡宾-金属和金属-酰胺键表现出高的灵活性，导致构象自由，这对它们的物理性质有很大的影响。在此，我们报告CMA配合物与（1）近共面，（2）扭曲，（3）倾斜，（4）倾斜扭曲的供体和受体配体之间的取向和说明的影响，优先基态构象的发光量子产率和激发态寿命。性能被认为是最佳的结构与部分扭曲和/或倾斜的构象，导致辐射率超过1 × 106 s-1。虽然金属原子对HOMO和LUMO的贡献很小，但它们在低位激发态之间提供了足够的自旋轨道耦合，从而将激发态寿命降低到500 ns。在同一时间，高的光致发光量子产率保持强烈倾斜的发射器在主机矩阵。基于这些新的发射器设计的概念验证有机发光二极管（OLED）被制造，具有19.1%的最大外部量子效率（EQE）和低器件滚降效率。瞬态电致发光的研究表明，新的CMA发射器的分子设计概念可以成功地转化为OLED器件。
Carbene–metal–amides (CMAs) are an emerging class of photoemitters based on a linear donor–linker–acceptor arrangement. They exhibit high flexibility about the carbene–metal and metal–amide bonds, leading to a conformational freedom which has a strong influence on their photophysical properties. Herein we report CMA complexes with (1) nearly coplanar, (2) twisted, (3) tilted, and (4) tilt-twisted orientations between donor and acceptor ligands and illustrate the influence of preferred ground-state conformations on both the luminescence quantum yields and excited-state lifetimes. The performance is found to be optimum for structures with partially twisted and/or tilted conformations, resulting in radiative rates exceeding 1 × 106 s–1. Although the metal atoms make only small contributions to HOMOs and LUMOs, they provide sufficient spin–orbit coupling between the low-lying excited states to reduce the excited-state lifetimes down to 500 ns. At the same time, high photoluminescence quantum yields are maintained for a strongly tilted emitter in a host matrix. Proof-of-concept organic light-emitting diodes (OLEDs) based on these new emitter designs were fabricated, with a maximum external quantum efficiency (EQE) of 19.1% with low device roll-off efficiency. Transient electroluminescence studies indicate that molecular design concepts for new CMA emitters can be successfully translated into the OLED device.
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影响因子：
16.6
作者：
Cui, Lin-Song;Nomura, Hiroko;Adachi, Chihaya
通讯作者：
Adachi, Chihaya
影响因子：
29.4
作者：
Conaghan, Patrick J.;Menke, S. Matthew;Credgington, Dan
通讯作者：
Credgington, Dan
影响因子：
5.7
作者：
Foeller, Jelena;Marian, Christel M.
通讯作者：
Marian, Christel M.
DOI：
10.1007/bf01114537
发表时间：
1990-04-01
期刊：
THEORETICA CHIMICA ACTA
影响因子：
--
作者：
ANDRAE, D;HAUSSERMANN, U;PREUSS, H
通讯作者：
PREUSS, H
影响因子：
15
作者：
Freeman, David M. E.;Musser, Andrew J.;Bronstein, Hugo
通讯作者：
Bronstein, Hugo