Two luminescent lanthanide–organic frameworks containing bithiophene groups for the selective detection of nitrobenzene and Fe3+

Abstract

Two lanthanide–organic frameworks formulated as [Eu₂(DMTDC)₃(DEF)₄]·DEF·6H₂O (1) and [Tb₂(DMTDC)₃(DEF)₄]·DEF·6H₂O (2) (H₂DMTDC = 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid and DEF = N,N-diethylformamide) have been synthesized under solvothermal conditions by using a bithiophene dicarboxylate organic ligand, H₂DMTDC. Compounds 1 and 2 are isomorphous and feature 3D frameworks with uninodal six-connected pcu α-Po topology structures. The systematic luminescence experiments reveal that 1 and 2 can be used as fast-response fluorescence sensors for the sensitive detection of nitrobenzene and Fe³⁺ ions with favorable recyclability through fluorescence quenching.