Two Series of Lanthanide Metal‐Organic Frameworks Constructed from Crown‐Ether‐Like Secondary Building Units

Two series of lanthanide metal-organic frameworks, [KLn3(FDCA)5(H2O)5]·solvent (1Ln) (Ln = La 1, Ce 2, Pr 3), [K4Ln8(FDCA)14(H2O)30]·2(H2FDCA)·DMAC·10(H2O) (2Ln) (Ln = Eu 4, Gd 5, Tb 6, Dy 7, Er 8, DMAC = N,N-dimethylacetamide), have been prepared by solvothermal reactions of 2,5-furandicarboxylic acid (H2FDCA) and KNO3 with the corresponding lanthanide nitrate. X-ray crystal structure analyses show that 1Ln possesses a 3D network based on the “16-crown-6-like” secondary building unit (SBU), whereas 2Ln exhibits a 1D framework with a “23-crown-9-like” SBU. The structural investigation unambiguously demonstrated that the lanthanide contraction affects the formation of 1Ln and 2Ln. Meanwhile, the solid-state photoluminescent properties of 4 and 6 were also investigated at room temperature and the luminescence intensity of 4 is sensitive to small molecules.