Cd(II) frameworks with tetracarboxylate and imidazole-containing ligands: Syntheses, structures, adsorption and sensing properties

Two novel metal-organic frameworks (MOFs) [Cd2(tib)(tpe)]·5DMA·H2O (1) and [Cd4(tipe)2(tpe)2]·15CH3OH·11H2O (2) (DMA ​= ​N,N-dimethylacetamide) were achieved by using cadmium(II) nitrate tetrahydrate to react with mixed multicarboxylate ligand of tetrakis(4-carboxyphenyl)ethene (H4tpe) and imidazole-containing one of 1,3,5-tris(1-imidazolyl)benzene (tib) or 1,1,2,2-tetrakis(4-(1-imidazolyl)phenyl)ethene (tipe) under solvothermal conditions. Both MOFs 1 and 2 have three-dimensional (3D) framework structures with distinct topologies. Due to the outstanding stability, porous structure and luminescence property, it was found that 1 can selectively adsorb gas molecules of CO2, light hydrocarbons as well as dye molecules of methyl orange (MO) and methyl blue (MB), and has selectivity for fluorescent sensing Fe3+. [Display omitted] Cd(II) frameworks with 3D porous structures have been successfully fabricated by solvothermal reactions of Cd(II) salt with tetracarboxylate and imidazole-containing ligands. The frameworks show selectivity for sensing iron (III) ions and adsorbing gas and dye molecules. •3D Cd(II) frameworks with mixed ligands were fabricated and characterized.•The Cd(II) frameworks show selectivity for fluorescent sensing Fe3+.•The porous frameworks can selectively adsorb gas and dye molecules.