Miao Wei-Ni, Liu Bing, Li Hong, Zheng Shu-Jin, Jiao Huan, Xu Ling
Key Laboratory of Macromolecular Science of Shaanxi Province, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Laboratory for Advanced Energy Technology, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi Province, P. R. China.
College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an 710021, Shaanxi Province, P. R. China.
Inorg Chem. 2022 Sep 12;61(36):14322-14332. doi: 10.1021/acs.inorgchem.2c02025. Epub 2022 Aug 26.
This work presents three series of Eu/Tb metal-organic frameworks (MOFs) containing benzophenone-4,4'-dicarboxylic acid (HBPNDC), 4,4'-dicarboxydiphenyl ether (HOBA), and terephthalic acid (HBDC) as the ligands. Eu/Tb MOFs have the same structural features in that their 3D frameworks are simplified as 2,3,10-connected {4.6}{4.6.8.10}{4} topological networks. The solid-state fluorescence spectra of three Eu/Tb MOF series are attributed to the combined emissions of D → F ( = 1-4) transitions in Eu and D → F ( = 6-5) transitions in Tb. The : of Eu/Tb MOFs is optimized as 1:69 based on the relationships between / and :; that is, EuTb-L (L = BPNDC, OBA, and BDC) were selected to carry out the following temperature ()-sensing tests. The fluorescence mechanism of EuTb-L can be explained by a ligand-to-metal charge transfer combined with an intermetallic Tb → Eu energy transfer. The -dependent fluorescence indicates linear relationships with sensitivities of 1.85% K for EuTb-BPNDC, 6.49% K for EuTb-OBA, and 0.28% K for EuTb-BDC. The influence of on the lowest excited triplet energy levels (1 values) of the ligands reveals that the ligand energy regulation impacts their fluorescence properties, including the sensitivity, fluorescence quenching rate, quantum yield, and fluorescence lifetime. This shows that EuTb-BPNDC is sufficiently sensitive to , making it applicable in noncontact measurements.
这项工作展示了三个系列的铕/铽金属有机框架（MOF），它们包含二苯甲酮 - 4,4'-二羧酸（HBPNDC）、4,4'-二羧基二苯醚（HOBA）和对苯二甲酸（HBDC）作为配体。铕/铽MOF具有相同的结构特征，其三维框架简化为2,3,10连接的{4.6}{4.6.8.10}{4}拓扑网络。三个铕/铽MOF系列的固态荧光光谱归因于铕中D→F（J = 1 - 4）跃迁和铽中D→F（J = 6 - 5）跃迁的组合发射。基于I/I和I/Tb的关系，铕/铽MOF的I/I被优化为1:69；也就是说，选择EuTb - L（L = BPNDC、OBA和BDC）进行以下温度（T）传感测试。EuTb - L的荧光机制可以通过配体到金属的电荷转移与金属间Tb→Eu的能量转移来解释。温度依赖性荧光表明其与灵敏度呈线性关系，EuTb - BPNDC的灵敏度为1.85% K，EuTb - OBA的灵敏度为6.49% K，EuTb - BDC的灵敏度为0.28% K。温度对配体最低激发三重态能级（T1值）的影响表明，配体能量调节影响其荧光性质，包括灵敏度、荧光猝灭速率、量子产率和荧光寿命。这表明EuTb - BPNDC对温度足够敏感，使其适用于非接触温度测量。
