A microporous lanthanum metal–organic framework as a bi-functional chemosensor for the detection of picric acid and Fe3+ ions

Abstract

A microporous lanthanum metal–organic framework [La(TPT)(DMSO)₂]·H₂O (La-MOF (1)), has been synthesized using a rigid unsymmetrical tricarboxylate ligand of p-terphenyl-3,4′′,5-tricarboxylic acid (H₃TPT). The structure of 1 is constructed by bi-nuclear lanthanum clusters and fully deprotonated TPT³⁻ ligands, which can be simplified into a 3,6-connected flu-3,6-C2/c topology with a point symbol of (4⁴·6)₂(4·6²·8⁷·10²). The π-electron rich ligand H₃TPT enables 1 to have blue luminescence when excited at 342 nm at ambient temperature. Meanwhile, 1 exhibits the selective detection of picric acid (PA) and Fe³⁺ ions in ethanol solution over other nitroaromatic compounds and metal ions. The high quenching efficiency and selectivity of 1 makes it a potential bi-functional chemosensor for both PA and Fe³⁺ ions.