2D lanthanide coordination polymers as multi-responsive luminescence sensors for selective and sensitive recognition of Cr(VI)/MnO4− anions and broad-spectrum detection of antibiotics

Abstract

Three new Ln(III)-CPs, {[Ln2(HL)2(H2O)2]·H2O}n (Ln=La (1), Eu (2) and Tb(3); H4L ​= ​1,1'-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid)) were hydrothermally synthesized and characterized by elemental analyses, IR, TG, PXRD and single-crystal X-ray diffraction. These isostructural CPs display 2D layer-like structures with a TiS2 topology constructed from inter-connected cage-like SBBs. The Eu-CP and Tb-CP exhibit characteristic luminescent emissions based on metal ions and possess selective recognition ability toward Cr(VI) and MnO4− ions in aqueous solution. They can also act as broad-spectrum fluorescent probes to detect common antibiotics. Furthermore, the fluorescence quenching mechanisms of two CPs were also studied in detail by combination of the PXRD patterns, UV–vis absorption spectra and theoretical calculations.