Bifunctional Luminescent Rare Earth Metal-Organic Frameworks for Highly Sensing Fe3+ Ions and TNP

Two isostructural rare earth metal-organic frameworks, namely [Re-2(BBTC)(DMF)(5)Cl-2]center dot 2DMF center dot H2O [BBTC4- = 1,1'-butadiynebenzene-3,3',5,5'-tetracarboxylate, Re = Y (1) and Ho (2)], have been prepared via solvothermal reaction. Single crystal X - ray analyses reveal that complexes 1 and 2 both crystallize in the P2(1)/m space group. Topological analyses suggest that these frameworks possess the same two-dimensional (2D) (4,4)-connected networks. Notably, the emission spectrum reveals the fluorescence of complex 1 is mainly from the ligands to ligands charge transfer transition. Further investigation indicates that complex 1 can act as a fluorescent sensor for highly sensitive and selective detection of Fe3+ and 2,4,6-trinitrophenol (TNP) in MeCN solution, the quenching constants (K-sv) are 1.45 x 10(5) M-1 for Fe3+ and 4.08 x 10(4) M-1 for TNP, with the detection limit (LOD) of 0.12 mu M for Fe3+ and 0.52 mu M for TNP. Furthermore, the possible sensing mechanisms of complex 1 as bifunctional sensors have been studied based on experiments.