Synthesis, Structure and Luminescent Property of an Europium(III) Coordination Polymer

A novel europium(III) coordination polymer, [Eu-3(pydc)(3)(SO4)(H2O)(5)(ox)(0.5)]center dot 3H(2)O (1, H(2)ox = oxalic acid, H(2)pydc = pyridine-2,6-dicarboxylic acid), has been synthesized hydrothermally from the self-assembly of lanthanide ions (Eu3+) with the flexible oxalic acid and the rigid pyridine-2,6-dicarboxylic acid ligands, respectively. It crystallizes in the triclinic system, space group P (1) over bar with a = 11.225(4), b = 12.390(5), c = 13.752(5) angstrom, alpha = 89.228(7), beta = 71.142(6), gamma = 75.552(6)degrees, D-c = 2.317 g/cm(3), mu = 5.480 mm(-1), F(000) = 1150, Z = 2, the final R = 0.0351 and wR = 0.0949 for 8782 observed reflections with I > 2 sigma(I). Structural analysis reveals that complex 1 exhibits a three-dimensional metal-organic framework via pi-pi stacking interactions. In addition, complex 1 displays a red fluorescence emission in the solid state at room temperature, which corresponds to the D-5(0) -> F-7(2) transition of Eu3+ ions.