A 12-Connected [Y(4)((μ(3)-OH)(4)](8+) Cluster-Based Luminescent Metal-Organic Framework for Selective Turn-on Detection of F(−) in H(2)O

Fluoride ion (F(−)) is one of the most hazardous elements in potable water. Over intake of F(−) can give rise to dental fluorosis, kidney failure, or DNA damage. As a result, developing affordable, equipment-free and credible approaches for F(−) detection is an important task. In this work, a new three dimensional rare earth cluster-based metal-organic framework assembled from lanthanide Y(III) ion, and a linear multifunctional ligand 3-nitro-4,4′-biphenyldicarboxylic acid, formulated as {[Y(μ(3)-OH)](4)[Y(μ(3)-OH)(μ(2)-H(2)O)(0.25)(H(2)O)(0.5)](4)[μ(4)-nba](8)}(n) (1), where H(2)nba = 3-nitro-4,4′-biphenyldicarboxylic acid, has been hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 crystallizes in tetragonal system with P [Formula: see text] 2(1)m space group, and features a 3D framework with 1D square 18.07(3)(2) Å(2) channels running along the [0,0,1] or c-axis direction. The structure of 1 is built up of unusual eight-membered rings formed by two types of {Y(4)O(4)} clusters connected to each other via 12 μ(4)-nba(2−) and 4 μ(3)-OH(−) ligands. Three crystallographic independent Y(3+) ions display two coordinated configurations with a seven-coordinated distorted monocapped trigonal-prism (YO(7)) and an eight-coordinated approximately bicapped trigonal-prism (YO(8)). 1 is further stabilized through O-H⋯O, O-H⋯N, C-H⋯O, and π⋯π interactions. Topologically, MOF 1 can be simplified as a 12-connected 2-nodal Au(4)Ho topology with a Schläfli symbol {4(20)·6(28)·8(18)}{4(3)}(4) or a 6-connected uninodal pcu topology with a Schläfli symbol {4(12)·6(3)}. The fluorescent sensing application of 1 was investigated to cations and anions in H(2)O. 1 exhibits good luminescence probing turn-on recognition ability toward F(−) and with a limit detection concentration of F(−) down to 14.2 μM in aqueous solution (K(ec) = 11403 M(−1), R(2) = 0.99289, σ = 0.0539). The findings here provide a feasible detection platform of LnMOFs for highly sensitive discrimination of F(−) in aqueous media.