One-dimensional channel-structured Eu-MOF for sensing small organic molecules and Cu2+ ion

Two new lanthanide metal-organic frameworks Ln(FBPT)(H2O)(DMF) (FBPT = 2'-fluoro-biphenyl-3,4',5-tricarboxylate, Ln = Eu and Tb) were prepared under solvothermal conditions. Single crystal X-ray diffraction analyses reveal that the two compounds are isostructurally related with the same one-dimensional channel structure on the basis of FBPT as an organic linker. Herein, the Eu(FBPT)(H2O)(DMF) (EuL) is selected as a representative sample for luminescent measurements. Study of the photoluminescence properties reveals that the EuL exhibits red emission, corresponding to the D-5(0) -> F-7(J) (J = 1-4) transitions of the Eu3+ ion under UV light excitation. Most interestingly, when this compound was immersed in the different organic solvents and metal ion DMF solutions, it shows highly selective and sensitive sensing for small organic molecules and Cu2+ ions. In connection to this, a probable sensing mechanism was also discussed in this paper.