Ren Miao, Wang Yu, Zhang Shuai, Yao Jiandong, Zou Bingsuo, Zeng Ruosheng
State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, School of Physical Science and Technology, Guangxi University, Nanning 530004, China.
Inorg Chem. 2024 Dec 23;63(51):24410-24420. doi: 10.1021/acs.inorgchem.4c04423. Epub 2024 Dec 10.
Metal halide luminescent materials, particularly those doped with ns ions, exhibit exceptional optical properties. However, the luminescent mechanisms associated with the stereochemical activity of lone-pair electrons remain insufficiently explored. In this study, zero-dimensional (0D) tin-based halide (CHN)SnCl is utilized as a model system to investigate the effects of lattice distortion and lone-pair electron expression on fluorescence emission characteristics by doping with 6s and 5s ions. The findings reveal that compared to 6s ions, 5s ion doping results in stronger electron-phonon coupling, causing significant octahedral lattice distortion and producing unique dual emissions along with a large Stokes shift of 317 nm. Remarkably, even at temperatures as high as 360 K, (CHN)SnCl:Sb maintains its dual emission due to insufficient thermal activation energy to promote electron transition from excited state 1 to excited state 2. In contrast, 6s doping exhibits a single blue emission with a small Stokes shift of 101 nm. Additionally, calculations of the electron localization function reveal that 5s lone pairs exhibit static stereochemical expression with specific spatial orientation, while 6s lone pairs display dynamic behavior. These findings highlight the critical role of lone-pair stereochemistry in governing the photophysical properties of ns-doped metal halides, offering new insights into their luminescent mechanisms.
金属卤化物发光材料，特别是那些掺杂ns离子的材料，具有优异的光学性能。然而，与孤对电子的立体化学活性相关的发光机制仍未得到充分探索。在本研究中，零维（0D）锡基卤化物（CHN）SnCl被用作模型系统，通过掺杂6s和5s离子来研究晶格畸变和孤对电子表达对荧光发射特性的影响。研究结果表明，与6s离子相比，5s离子掺杂导致更强的电子-声子耦合，引起显著的八面体晶格畸变，并产生独特的双重发射以及317 nm的大斯托克斯位移。值得注意的是，即使在高达360 K的温度下，（CHN）SnCl:Sb由于热激活能量不足，无法促进电子从激发态1跃迁到激发态2，仍保持其双重发射。相比之下，6s掺杂呈现出单一的蓝色发射，斯托克斯位移较小，为101 nm。此外，电子定位函数的计算表明，5s孤对电子表现出具有特定空间取向的静态立体化学表达，而6s孤对电子表现出动态行为。这些发现突出了孤对立体化学在控制ns掺杂金属卤化物的光物理性质方面的关键作用，为其发光机制提供了新的见解。
