Tetra-Nuclear Cluster-Based Lanthanide Metal-Organic Frameworks as White Phosphor, Information Encryption, Self-Calibrating Thermometers, and Fe 2+ Sensors.

The application of one kind of metal-organic framework (MOF) material used in multiple fields is one of the most interesting research topics. In this work, four new tetra-nuclear cluster-based lanthanide metal-organic frameworks (LnMOFs) [Ln 2 (BTDB) 3 (DMA)(phen)] n (Ln = Tb TbMOF , Eu EuMOF , Gd GdMOF , Tb 1.830 Eu 0.170 Tb,EuMOF , 3,5-bis(trifluoromethyl)-4',4″-dicarboxytriphenylamine = H 2 BTDB , 1,10-phenanthroline = phen) are obtained based on the ligand of H 2 BTDB that is synthesized in our laboratory, and the precise single-crystal structure of H 2 BTDB is obtained for the first time. The white phosphor was obtained by facilely hybridizing two components of the orange-yellow emission phosphor of Tb,EuMOF and the blue luminescence material of triphenylamine according to the trichromatic theory. At the same time, TbMOF , EuMOF , Tb,EuMOF , and the white phosphor can be used for information encryption, demonstrating their potential application in the field of anti-counterfeiting. Tb,EuMOF is also a multi-mode and self-calibrating thermometer within a broad temperature range of 110-300 K. Further studies show that EuMOF is a rapid response sensor for Fe 2+ , with a very low limit of detection of 2.0 nM, which is much lower than the national standards for Fe 2+ (GB 5749-2005, 5.357 μM). It can achieve strong anti-interference detection of Fe 2+ in actual samples of tap water and lake water. In addition, EuMOF can also be made into an easy-to-use sensing device of test paper for real-time and visual sensing of Fe 2+ .