Cadmium MOF-BasedVaried {Cd₂} Clustersas Multifunctional Fluorescence Sensors to Detect Fe³⁺,Cr₂O₇^2–, TNP, and NFT

Metal–organic frameworks (MOFs) have been widely used in the field of fluorescence sensing due to their highly ordered spatial structures, large porosity, and uniform pore sizes. Here, two new Cd- MOFs (JLJU-2 and JLJU-3), based on the ligand 4-(1H-1,2,4-triazol-1-yl)phenyl-4,2’:6’,4”-terpyridine (L) and two carboxylate ligands, were synthesized by the solvothermal method. JLJU-2 and JLJU-3 were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, UV–visible spectroscopy, and thermogravimetric analysis. Respectively, JLJU-2 and JLJU-3 exhibit 2D and 3D structures using the L ligand and 2-aminoterephthalic acid (2-ATA)/nitroterephthalic acid (NTPA), adopted with different coordination modes. Furthermore, the porous crystal structures of JLJU-2 and JLJU-3 enable them to be well-suited for applications in the field of fluorescence sensing, in which JLJU-3 can detect Fe³⁺, Cr₂O₇^2–, TNP, and NFT with high selectivity and sensitivity. This work provides useful information for a versatile fluorescence sensing platform for the detection of environmental contaminants.