Yan Xinyue, Song Shi-Yu, Liang Shicong, Liu Kai-Kai, Liu Xiao-Ting, Lu Chao
College of Chemistry, Pingyuan Laboratory, Zhengzhou University Zhengzhou 450001 China
Henan Key Laboratory of Diamond Optoelectronic Material and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University Zhengzhou 450001 China.
Chem Sci. 2025 Aug 12. doi: 10.1039/d5sc02235e.
Through-space charge transfer (TSCT) thermally activated delayed fluorescence (TADF) materials have recently shown great potential for applications in X-ray detection and imaging due to their efficient triplet exciton utilization. By rational tuning of molecular/electronic structures of D and A moieties and precise regulation of TSCT interactions, tunable emission and TSCT-based TADF can be achieved. However, the TSCT interactions in organic D-A systems are somewhat difficult to design and control precisely resulting from relatively weak D-A supramolecular interactions. Herein, we propose a concept of TADF host-guest MOF scintillators with modulational TSCT interactions by confining D molecules as guests in the pore spaces of host MOFs composed of A ligands. Based on the synergy of the coordination and D-A interactions, various D molecules can be introduced into MOFs and manipulation of TSCT interactions can be achieved. As a result, tunable emission wavelengths spanning from 532 nm to 738 nm and successful construction of TADF host-guest MOF materials for X-ray scintillators can be achieved. Thanks to stable and enhanced triplet exciton utilization efficiency induced by TADF, the scintillator performance of compound 1 obviously surpassed that of separate D and A components as well as that of traditional organic commercial scintillator anthracene. The potential application of this scintillator in X-ray imaging was also demonstrated. This work provides a novel strategy for developing host-guest MOF scintillators.
通过空间电荷转移（TSCT）的热激活延迟荧光（TADF）材料由于其对三重态激子的高效利用，最近在X射线检测和成像应用中显示出巨大潜力。通过合理调节给体（D）和受体（A）部分的分子/电子结构以及精确调控TSCT相互作用，可以实现可调谐发射和基于TSCT的TADF。然而，由于相对较弱的D - A超分子相互作用，有机D - A体系中的TSCT相互作用在一定程度上难以精确设计和控制。在此，我们提出了一种具有调制TSCT相互作用的TADF主客体金属有机框架（MOF）闪烁体的概念，即将D分子作为客体限制在由A配体组成的主体MOF的孔道空间中。基于配位和D - A相互作用的协同作用，可以将各种D分子引入MOF中并实现对TSCT相互作用的调控。结果，可以实现从532 nm到738 nm的可调发射波长，并成功构建用于X射线闪烁体的TADF主客体MOF材料。由于TADF诱导的稳定且增强的三重态激子利用效率，化合物1的闪烁体性能明显超过单独的D和A组分以及传统有机商业闪烁体蒽。还展示了这种闪烁体在X射线成像中的潜在应用。这项工作为开发主客体MOF闪烁体提供了一种新策略。
