Two water-stable Cd(II)-MOFs as multiresponsive chemosensor with high sensitively and selectively detection of Fe3+, Cr2O72− and MnO4− ions

Two water-stable Cd(II)-MOFs, [CdL0.5(H2O)] (1) and {[Cd3(H2L)(dtb)2(H2O)]·3H2O}n (2) [H4L ​= ​1,1'-(ethane-1,2-diyl)bis (1H-imidazole-4,5-dicarboxylic acid); H2dtb ​= ​1,4-di (1H-tetrazol-5-yl)benzene) has been hydrothermally synthesized and characterized by elemental analyses, IR, TG, and X-ray single-crystal diffraction. Complex 1 exhibits a 3D 6-connected framework based on L4− ligands μ6-linking [Cd2O2] unit, and complex 2 possesses a 3D (3,8)-connected porous framework built by H2L2− and dtb2− ligands bridging [Cd3O2] units. The luminescence properties were investigated, showing that 1 and 2 can display high sensitivity and selectivity for detecting Fe3+, Cr(VI) and MnO4− ions in aqueous solutions via luminescence quenching effects. Furthermore, possible sensing mechanism was investigated in this paper.