Synthesis, crystal structures and properties of a series of three-dimensional lanthanide coordination polymers with the rigid and flexible mixed dicarboxylate ligands of 1,4-benzene dicarboxylic acid and succinic acid

A series of new lanthanide coordination polymers, with the formula [Ln(Suc)0.5(p-BDC)] (Ln = Eu (1), Sm (2), Tb (3), Pr (4), Ho (5); H2Suc = succinic acid; p-H2BDC = 1,4-benzene dicarboxylic acid), have been synthesized under hydrothermal condition and all of them have been structurally characterized. X-ray diffraction analyses reveal that complexes 1–5 are isostructural and crystallized in orthorhombic space group Pbca. One-dimensional infinite inorganic edge-sharing polyhedra chains formed by lanthanide ions and tetradentate carboxyl groups of succinic acid ligands, link to each other through the carbon atoms of succinic acid ligands and phenyl groups of the 1,4-benzene dicarboxylic acid ligands, to lead to a three-dimensional framework structure. In addition, the phase purities of the bulk samples were identified by X-ray powder diffraction. The photoluminescent properties of 1 and 3 were discussed in detail.