Selective fluorescence detection of anilines and Fe3+ ions by two lanthanide metal–organic frameworks

Abstract

Two isostructural lanthanide metal–organic frameworks [Ln₂(TDC)₃(CH₃OH)₂·(CH₃OH)] (Ln = Eu, 1; Tb, 2, TDC = 2,5-thiophenedicarboxylic acid) were successfully synthesized. For the two compounds, the participation of the fluorescent ligand H₂L sensitized and enhanced the lanthanide characteristic emissions of the two MOFs as expected. Luminescent investigations reveal that 1 and 2 can be efficient multifunctional luminescent materials for high-sensitivity sensing of aromatic amine compounds and metal ions, especially for p-nitroaniline and Fe³⁺ ions with a fluorescence quenching effect. Additionally, diphenylamine significantly enhanced the ligand-based emission of 2 under the same experimental conditions. These features make 1 and 2 promising candidates for the development of multifunctional sensors in the future.