Circularly Polarized Thermally Activated Delayed Fluorescence Emitters in Through-Space Charge Transfer on Asymmetric Spiro Skeletons,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Circularly Polarized Thermally Activated Delayed Fluorescence Emitters in Through-Space Charge Transfer on Asymmetric Spiro Skeletons
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2020-10-06 , DOI: 10.1021/jacs.0c08980
Sheng-Yi Yang ₁ , Ya-Kun Wang ₁ , Chen-Chen Peng ₁ , Zheng-Guang Wu ₂ , Shuai Yuan ₁ , You-Jun Yu ₁ , Hao Li ₃ , Tong-Tong Wang ₁ , Hong-Cheng Li ₁ , You-Xuan Zheng ₂ , Zuo-Quan Jiang ₁ , Liang-Sheng Liao _{1,

4}

Affiliation

This work describes a strategy to produce circularly polarized thermally activated delayed fluorescence (CP-TADF). A set of two structurally similar organic emitters SFST and SFOT are constructed, whose spiro architectures containing asymmetric donors result in chirality. Upon grafting within the spiro frameworks, the donor and acceptor are fixed proximally in a face-to-face manner. This orientation allows intramolecular through-space charge transfer (TSCT) to occur in both emitters, leading to TADF properties. The donor units in SFST and SFOT have a sulfur and oxygen atom, respectively; such a subtle difference has great impacts on their photophysical, chiroptical, and electroluminescence (EL) properties. SFOT exhibits greatly enhanced EL performance in doped organic light-emitting diodes, with external quantum efficiency (EQE) up to 23.1%, owing to the concurrent manipulation of highly photoluminescent quantum efficiency (PLQY, ∼90%) and high exciton utilization. As a comparison, the relatively larger sulfur atom in SFST introduces heavy atom effects and leads to distortion of the molecular backbone that lengthens the donor-acceptor distance. SFST thus has lower PLQY and faster nonradiative decay rate. The collective consequence is that the EQE value of SFST, i.e., 12.5%, is much lower than that of SFOT. The chirality of these two spiro emitters results in circularly polarized luminescence. Because SFST has a more distorted molecular architecture than SFOT, the luminescence dissymmetry factor (|glum|) of circularly polarized luminescence of one enantiomer of the former, namely, either (S)-SFST or (R)-SFST, is almost twice that of (S)-SFOT/(R)-SFOT. Moreover, the CP organic light-emitting diodes (CP-OLEDs) show obvious circularly polarized electroluminescence (CPEL) signals with gEL of 1.30 × 10-3 and 1.0 × 10-3 for (S)-SFST and (S)-SFOT, respectively.

中文翻译：

圆偏振热激活延迟荧光发射器在非对称螺骨架上的空间电荷转移中

这项工作描述了一种产生圆偏振热激活延迟荧光 (CP-TADF) 的策略。构建了一组两个结构相似的有机发射器 SFST 和 SFOT，其包含不对称供体的螺旋结构导致手性。在螺框架内移植后，供体和受体以面对面的方式在近端固定。这种方向允许分子内通过空间电荷转移 (TSCT) 在两个发射器中发生，从而产生 TADF 特性。SFST 和 SFOT 中的供体单元分别具有硫和氧原子；这种细微的差异对它们的光物理、手性光学和电致发光 (EL) 特性有很大影响。SFOT 在掺杂有机发光二极管中表现出极大增强的 EL 性能，外量子效率 (EQE) 高达 23.1%，由于同时操纵高光致发光量子效率（PLQY，~90%）和高激子利用率。相比之下，SFST 中相对较大的硫原子会引入重原子效应并导致分子骨架扭曲，从而延长供体 - 受体距离。因此，SFST 具有更低的 PLQY 和更快的非辐射衰减率。集体后果是SFST 的EQE 值，即12.5%，远低于SFOT。这两个螺发射体的手性导致圆偏振发光。由于 SFST 具有比 SFOT 更扭曲的分子结构，前者的一种对映体（即 (S)-SFST 或 (R)-SFST）的圆偏振发光的发光不对称因子 (|glum|) 几乎是其两倍(S)-SFOT/(R)-SFOT。而且，

更新日期：2020-10-06

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南