Developing highly stable materials for harmful ion detection in a water environment is of much importance and challenging. Here, two three-dimensional porous structures (termed as Eu-MOF and Tb-MOF) were successfully constructed by the strategy of anchoring Eu3+/Tb3+ and rigid 1,2,4,5-benzenetetracarboxylic acid (H4BTEC) imidazole units (H3ICA) onto its frameworks. The obtained Eu-MOF and Tb-MOF display high water stability and fluorescence stability up to 30 days. Furthermore, luminescent studies reveal that Eu-MOF and Tb-MOF show rapid, recursive, and simultaneous sensing Fe3+ and Cr2O7 2–/CrO4 2– ions in water. In addition, the sensing function possesses remarkable cyclicity and selectivity even with the existence of other analogous ions.

Here, two novel 3D Cd­(II)-MOFs, [Cd3·L·(BTB)2·2DMF] and [(Cd3O2)·L·BTC] (denoted as CUST-532 and CUST-533, L = 9,10-bis­(N-benzimidazolyl)-anthracene, BTB = 1,3,5-tris­(4-carboxyphenyl) benzene, BTC = 1,3,5-benzenetricarboxylic acid, CUST = Changchun University of Science and Technology), were synthesized by solvothermal conditions. Both CUST-532 and CUST-533 are 3D (3,8)-c topological nets with the same point symbol of {43}2{46·618·84}. PXRD and TGA analyses prove that CUST-532 and CUST-533 have good structural stability and thermal stability. On the basis of the high fluorescence characteristics, the results of fluorescence sensing experiments show that CUST-532 and CUST-533 can be used as multifunctional chemical sensors to achieve rapid fluorescence quenching response to antibiotic residues, Fe3+ and Cr2O7 2– ions at a much lower concentration. Furthermore, the possible mechanisms of fluorescence quenching in the sensing process were systematically studied by PXRD, UV–vis, fluorescence decay lifetime, and density functional theory.

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The effective detection of Fe 3+ , Cr 2 O 7 2− , and picric acid (TNP) is of immense significance in chemical and environmental fields. In this paper, five novel luminescent Cd(II)-metal−organic frameworks (MOFs) (CUST-601−605) based on the ligand of 1-(9-(1H-1,2,4-triazol-1-yl)anthracen-10-yl)-1H-1,2,4-triazole (tatrz) and a series of carboxylate ligands were synthesized via solvothermal reactions. CUST-601−605 are characterized by X-ray single-crystal diffraction, powder X-ray diffraction, and thermogravimetric analysis. CUST-601 and 605 show porous three-dimensional (3D) structures, and CUST-602 shows 2D network structures, with the ethanol molecules as the capping agents. CUST-603 and CUST-604 exhibit 3D and 2D structures, respectively, based on the controlled contents of organic ligands and capping agents. Luminescent experiments indicate that CUST-601, 602, and 604 show satisfactory sensitivity and selectivity for the detection of Fe 3+ , Cr 2 O 7 2− , and TNP. Further, CUST-603 and 605 are only used to determine Cr 2 O 7 2− and TNP sensitively. The MOF-based fluorescent sensors designed in this paper demonstrate the successful and feasible strategy to use anthracene-based ligands, which shows great potential in environmental detection applications.

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