Synthesis, structures and thermal properties of three new two-dimensional coordination networks assembled by lanthanide salts and carboxylate ligand

Three new rare-earth coordination polymers, [La2(PDC)2(NO3)2(H2O)3] (1) and [Dy(PDC)(ox)0.5(H2O)2] · H2O (2), and [Sm(PDC)(ox)0.5(H2O)2] · H2O (3) (H2PDC = pyridine-3,4-dicarboxylic acid, ox = oxalic acid), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single-crystal X-ray diffraction. Of the three compounds, La–O–La and Dy(Sm)–O–C–O–Dy(Sm) chains are cross-linked by PDC ligands into interesting two-dimensional framework structures. They represent, to the best of our knowledge, the first examples of rare-earth complexes in the {M/PDC} (M = metal) system.