A terbium(iii) lanthanide–organic framework as a platform for a recyclable multi-responsive luminescent sensor

Abstract

A terbium ( iii) lanthanide–organic framework provides a platform for a recyclable multi-responsive luminescent sensor for detecting Fe ³⁺, MnO ₄ ⁻, Cr ₂O ₇ ²⁻, and p-nitrotoluene (4-NT), which is the first reported MOF-based sensor for detecting explosive 4-NT.

Abstract

A terbium( iii) lanthanide–organic framework (534-MOF-Tb) with a green-emission signal was successfully obtained by the solvothermal reaction of Tb ³⁺ ions with the organic ligand H ₃TBOT (2,4,6-tris[1-(3-carboxylphenoxy)ylmethyl]mesitylene). 534-MOF-Tb contains microporous quadrangle channels with accessible Lewis-base sites and coordinated water molecules, which are feasible to anchor and recognise multifarious analytes. It can serve as a recyclable multi-responsive sensing material for detecting Fe ³⁺, MnO ₄ ⁻, Cr ₂O ₇ ²⁻, and p-nitrotoluene (4-NT). Significantly, this is the first reported MOF-based sensor for detecting explosive 4-NT. Moreover, the mechanism of the selective luminescence quenching response for Fe ³⁺, MnO ₄ ⁻, Cr ₂O ₇ ²⁻ or 4-NT can be mainly explained in terms of the competition between the absorption of the light source energy and the electronic interaction between the analyte and the TBOT ligand.