Toward rational design of TADF two-coordinate coinage metal complexes: understanding the relationship between natural transition orbital overlap and photophysical properties
Toward rational design of TADF two-coordinate coinage metal complexes: understanding the relationship between natural transition orbital overlap and photophysical properties
复制标题
走向合理设计TADF二配位造币金属配合物：理解自然跃迁轨道重叠与光物理性质之间的关系
DOI：
10.1039/d2tc00163b
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发表时间：
2022
影响因子：
6.4
通讯作者：
Thompson, Mark E.
中科院分区：
文献类型：
--
作者：
Li, Tian-yi;Schaab, Jonas;Djurovich, Peter I.;Thompson, Mark E.
制备了一系列具有卡宾-金属-酰胺结构的十二种二配位造币金属Cu、Ag和Au配合物。这些配合物在室温下均表现出配体间电荷转移 (ICT) 激发态的热辅助延迟荧光 (TADF) 发射，寿命短（小于 2 μs），并且光致发光量子产率接近一致。由于发射跃迁中取代基的参与以及不同的金属离子体积，发射态的自然跃迁轨道（NTO）重叠可以在0.21至0.41的宽范围内调节。对发射态 NTO 重叠与 TADF 关键光物理性质之间关系的研究表明，S1 态的单重态-三重态能隙和辐射衰变率随着 NTO 重叠呈指数增加。因此，当针对 NTO 重叠绘制时，总体 TADF 辐射衰减率达到最大值，为此类两配位造币金属络合物发光体中的高 TADF 辐射衰减率提供了 0.25 至 0.30 的理想区域。
A series of twelve two-coordinate coinage metal, Cu, Ag and Au, complexes with carbene-metal-amide structures were prepared. The complexes all display thermal assisted delayed fluorescence (TADF) emission at room temperature from interligand charge transfer (ICT) excited state with short lifetimes (less than 2 μs) and photoluminescent quantum yields that reach near unity. Owing to the involvement of the substituents in the emissive transitions and different metal ion volume, the natural transition orbital (NTO) overlap of the emissive state can be adjusted in a wide range from 0.21 to 0.41. Investigations on the relationship between the NTO overlap of the emissive state and key TADF photophysical properties demonstrated that both singlet–triplet energy gap and radiative decay rate of S1 state increase along with the NTO overlap exponentially. Consequently, the overall TADF radiative decay rate leads to a maximum when plotted against the NTO overlap, giving the ideal zone from 0.25 to 0.30 for high TADF radiative decay rate in this class of two-coordinate coinage metal complex luminophores.