Dy(III)-Based Metal–Organic Framework as a Fluorescent Probe for Highly Selective Detection of Picric Acid in Aqueous Medium

A dysprosium metal–organic framework, {[Dy(μ 2 -FcDCA) 1.5 (MeOH)(H 2 O)]·0.5H 2 O} n ( 1 ), where FcDCA = 1,1′-ferrocene dicarboxylic acid, was prepared by slow-diffusion technique at room temperature. The crystal structure analysis of 1 by single-crystal X-ray diffraction reveals different binding modes of FcDCA linkers coordinated with Dy(III) metal ions, which forms continuous porous two-dimensional (2D) infinite framework. The resulting 2D layers are linked by π···π interactions to build three-dimensional (3D) supramolecular framework. Observably, this thermally stable 3D architecture was topologically simplified as a three-connected uninodal net with fes topology. Furthermore, the practical applicability of 1 was investigated as a fluorescence sensor for the sensitive detection of picric acid in aqueous medium with an impressive detection limit of 0.71 μM with quenching constant ( K SV ) quantified to be 8.55 × 10 4 M –1 . The distinguished selectivity in the presence of other nitroaromatics suggests the possible incorporation of 1 in real-world futuristic diagnostic kits. Additionally, the electrochemical behavior of 1 exhibits reversible in nature attributed to the ferrocene/ferrocenium cation.