A multifunctional Eu-CP as a recyclable luminescent probe for the highly sensitive detection of Fe3+/Fe2+, Cr2O72-, and nitroaromatic explosives.

A novel 2D lanthanide coordination polymer {Eu-CP (1)} based on a 3-bis(3-carboxyphenyl)imidazolium (L) ligand was successfully assembled through a solvothermal method. Luminescence tests indicate that 1 has excellent selectivity and sensitivity to detect Fe3+/Fe2+, Cr2O72-, and a series of nitroaromatic explosives. Interestingly, 1 can effectively distinguish CrVI anions (CrO42-/Cr2O72-), which is difficult for most of the reported CPs. Furthermore, in the detection process, 1 can be simply and quickly regenerated and reused at least five times. As far as we know, 1 is the first multifunctional Eu-CP used as a luminescent probe to detect Fe3+/Fe2+, Cr2O72-, and a series of nitroaromatic explosives (NAEs) based on the imidazolium derivative.