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

Abstract

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+.