Dual-functional recyclable luminescent sensors based on 2D lanthanide-based metal-organic frameworks for highly sensitive detection of Fe3+ and 2,4-dinitrophenol

A series of lanthanide-based metal-organic frameworks (Ln-MOFs), namely [Ln(L2-)(HL-)(H2O)(2)](n) (Ln = Eu 1, Gd 2, Tb 3 and Dy 4, H2L = 5-(imidazol-1-yl)isophthalic acid) have been successfully assembled under solvothermal conditions. Compounds 1-4 exhibit a 2D corrugated layer structure with {4(4).6(2)}-sql topology based on [Ln(2)(CO2)(6)(H2O)(4)] units containing uncoordinated carboxylate groups, which further forms a 3D supramolecular structure through hydrogen bond interactions. Compounds 1 and 3 display excellent applications as luminescent sensors for sensing 2,4-dinitrophenol (2,4-DNP) in ethanol system and Fe3+ in aqueous solution with high sensitivity and selectivity based on luminescence quenching effects. Interestingly, 1 and 3 display excellent recyclable behaviors and can be recycled at least 5 times for sensing 2,4-DNP and Fe3+. These two compounds are the first reported dual-functional Ln-MOFs sensors for detecting 2,4-DNP and Fe3+. Therefore, these two materials may be an excellent dual-functional recyclable luminescent sensor for 2,4-dinitrophenol and Fe3+. (C) 2017 Elsevier Ltd. All rights reserved.