A Versatile Luminescent Metal-Organic Framework for Selective Detection of Fe(III) Cations and Cr(VI) Anions

The heavy metal ion pollution has become one of the most serious environmental problems, which promotes the continuous exploration of new materials and methods to achieve efficient detection of heavy metal ions. Luminescent metal-organic frameworks (LMOFs) featuring the designable and functional structures and tunable luminescence properties exhibit excellent potential for the recognition and detection of heavy metal ions. Herein, a Cd(II)-based luminescence MOF {[Cd2(2F-bpdc)2(tib)]}n (NKM-103) (tib=1,3,5-tris(1-imidazolyl)benzene, 2F-H2bpdc= 3,3'-difluorobiphenyl-4,4'-dicarboxylic acid) has been designed and synthesized successfully. Derived from the characteristic of ligand with conjugated units, NKM-103 shows well fluorescence emission performance and potential as a sensor for detecting both Fe(III) cations and Cr(VI) anions (Cr2O72- and CrO42-) through turn-off effect. Moreover, NKM-103 for all three kinds of ions shows low detection limit and high selectivity.