Zhang Hong-Jin, Chen Zong-Ren, Chen Wan-Tao, Ye Jia-Wen, Chen Ling
Jiangmen Key Laboratory of Synthetic Chemistry and Cleaner Production, School of Environmental and Chemical Engineering, Wuyi University Jiangmen Guangdong 529000 PR China
School of Emergent Soft Matter, Center for Electron Microscopy, South China University of Technology Guangzhou 510006 China.
Chem Sci. 2025 Sep 15. doi: 10.1039/d5sc05999b.
Pressure-induced emission enhancement (PIEE) is relatively rare and holds greater research promise than pressure-induced emission quenching. However, reports on PIEE often overlook the influence of atmospheric oxygen, especially in porous materials. Additionally, since the impact of energy transfer between the excited state of luminescent probes and T(O) on oxygen sensitivity remains unclear, tuning the luminescence-based oxygen sensitivity at the molecular structural level is highly challenging. Here, we report a series of coordination polymers (CuXBP, X = I, Br, Cl). Although they have similar structures and comparable porosity, their oxygen quenching efficiencies differ significantly (ranging from 95.8% to 7.7%). Computational simulations reveal that the superior oxygen quenching efficiency of CuIBP stems from the minimal Δ (742 cm) between its T state and T(O). Additionally, under pressure, both CuClBP and CuBrBP exhibit the commonly observed red shift accompanied by luminescence quenching. However, CuIBP displays the less commonly observed PIEE, attributed to the reduced porosity after grinding, which lowers oxygen-sensing efficiency (from 95.8% to 33.2%). Compared to its unground state, this efficiency reduction in CuIBP substantially attenuates oxygen-induced quenching, resulting in stronger luminescence (>2-fold enhancement) under ambient conditions. This work establishes a novel strategy for designing oxygen sensing and PIEE materials.
压力诱导发射增强（PIEE）相对罕见，且比压力诱导发射猝灭具有更大的研究前景。然而，关于PIEE的报道往往忽视了大气氧的影响，尤其是在多孔材料中。此外，由于发光探针的激发态与三线态氧（T（O））之间的能量转移对氧敏感性的影响尚不清楚，在分子结构水平上调谐基于发光的氧敏感性极具挑战性。在此，我们报道了一系列配位聚合物（CuXBP，X = I、Br、Cl）。尽管它们具有相似的结构和相当的孔隙率，但其氧猝灭效率却有显著差异（范围从95.8%至7.7%）。计算模拟表明，CuIBP优异的氧猝灭效率源于其三线态与三线态氧之间最小的能隙差（742 cm）。此外，在压力下，CuClBP和CuBrBP均表现出常见的红移并伴有发光猝灭。然而，CuIBP表现出较少见的PIEE，这归因于研磨后孔隙率降低，从而降低了氧传感效率（从95.8%降至33.2%）。与未研磨状态相比，CuIBP的这种效率降低显著减弱了氧诱导的猝灭，导致在环境条件下发光更强（增强超过2倍）。这项工作建立了一种设计氧传感和PIEE材料的新策略。
