A new three-dimensional luminescent MOF for the detection of Fe3+, CrO42−, and Cr2O72− in aqueous solution

Abstract

A new luminescent MOF were synthesized by solvothermal method based on 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethene (TPPE), with the molecular structure of [Zn₂(TPPE)_0.5(ndc)₂]_n (ndc = 1,4-Naphthalenedicarboxylic acid) (LMOF-1). The single crystal structure indicates that LMOF-1 stacks in a three-dimensional structure. The fluorescence test results indicate that LMOF-1 emits blue light with quantum yield at 37.93 %, due to ligand–ligand charge transfer. PXRD and TG analysis confirmed that LMOF-1 has good stability, and PXRD analysis after different solvent exchanges confirmed that LMOF-1 has good stability in water. The results of ion titration experiments show that Fe³⁺, CrO₄²⁻, and Cr₂O₇²⁻ have significant quenching effects on LMOF-1, and the detection limits are 3.83 × 10⁻⁶ M, 2.57 × 10⁻⁵ M, and 4.33 × 10⁻⁶ M, respectively. Indicating that LMOF-1 can serve as a multifunctional ion detector.