Stable Interpenetrated Zirconium-Based Metal–Organic Framework for the Fluorescence Detection of MnO4–

In this work, a novel stable zirconium-based metal–organic framework (Zr-MOF) with the formula [Zr 6 O 4 (OH) 4 (PVDC) 6 ] 4 ·66DMF ( Zr-1, H 2 PVDC = ( E, E )-2,5-dimethoxy-1,4-bis[2-(4-carboxylatestyryl)]benzene; DMF = N, N -dimethylformamide) was synthesized by introducing a linear phenylenevinylene-based carboxylate ligand to react with ZrCl 4 under solvothermal conditions. According to single-crystal X-ray diffraction measurement, complex Zr-1 featured a 2-fold interpenetrated framework, in which the single coordination framework possessed a structure similar to that of the well-known Zr-MOF, UiO-66, constructed from [Zr 6 O 4 (OH) 4 ] 12+ clusters and carboxylate ligands PVDC 2– . Due to the introduction of the phenylenevinylene-functionalized ligand, complex Zr-1 exhibited a unique fluorescence sensing performance toward permanganate (MnO 4 – ) with different concentrations. At low concentrations, the fluorescence emission intensity of Zr-1 around 510 nm was enhanced significantly with an increase in the concentration of MnO 4 – in an aqueous suspension. However, while excess MnO 4 – was added into the suspension, the fluorescence emission intensity decreased significantly, and the single emission peak turned into five emission peaks upon the addition of MnO 4 – . Such a phenomenon has been scarcely reported in previous MOF-based fluorescence sensors. Moreover, complex Zr-1 showed high anti-interference capability for the detection of MnO 4 – both at low and high concentrations. This work may pave a new way for the development of MOF-based fluorescence sensing platforms.