A fluorescent sensor for highly selective sensing of nitro explosives and Hg(II) ions based on a 3D porous layer metal-organic framework

A 3D porous layer metal-organic framework, namely [Cd.BPDC)(0.5)(L1)(NO3)]center dot 3.4DMF (1), was synthesized under solvothermal conditions. The structure was characterized by single crystal X-ray diffraction analysis, powder X-ray diffraction (PXRD) analysis, thermogravimetric analysis (TGA), infrared spectrophotometry analysis and elemental analysis. The structure of 1 displays a 3D porous layer and can be classified as a (3,4)-connected topology with a point symbol of (4(2).6.3(8))(2)(4(2).6). The framework is stable to a certain degree. 1 can also be applied as a fluorescent sensor for small-molecule sensing, such as nitrobenzene (NB) and 2,4,6-trinitrophenol (TNP). In addition, 1 is a rare example of MOF-based fluorescent probes targeting environmentally relevant guest species, such as Hg(II) ions in aqueous solution, with high selectivity and sensitivity.