Four Lanthanide-Organic Frameworks Built from 2,2′-Dinitro-4,4′-biphenyldicarboxylic Acid

Four lanthanide-organic frameworks (LOFs), [LnL(15)(DMA)](n) (Ln=Eu (1), Gd (2), Tb (3), Dy (4); H2L= 2,2'-dinitro-4,4'-biphenyldicarboxylic acid, DMA=N,N-dimethylacetylamide), have been prepared by the solvothermal reaction of H2L and Ln(NO3)(3)center dot 6H(2)O. Their structures have been characterized by elemental analyses, IR, TGA, single-crystal and powder X-ray diffraction (XRD) studies. Crystal structure analyses show that LOFs 1 similar to 4 crystallize in the monoclinic system with C2/ c space group. LOFs 1 similar to 4 are isomorphous and possess a binodal (3,8)-connected three-dimensional (3D) topology network. All the LOFs exhibit high thermal stabilities (T-d>322 degrees C). Furthermore, 1 displays characteristic luminescence of Eu(Il1) ion while 3 only shows the emission peak of the L2- ligand. CCDC: 1549595, 1; 1549593, 2; 1549596, 3; 1549594, 4.