| Seven lanthanide oxalate-oxydiacetate mixed ligand coordination polymers {[Ln(oda)(H2O)x]2(ox)}n [ x = 3 for Ln = La, Ce, Pr, Nd, Gd, Tb and x = 2 for Er ] have been synthesized by the reaction of oxydiacetic acid (H2oda) and corresponding lanthanide oxide, nitrate, chloride or carbonate in high purity and higher yield under mild hydrothermal conditions. The oxydiacetic acid was decomposed into oxalic acid in this reaction condition. The seven compounds have been characterized by EA, IR and X-ray diffraction analysis. They have similar composition with the difference in the number of water molecules, and all complexes crystallize in the monoclinic systems and space groups P21/c. In the crystal structures of all the seven compounds, the oxydiacetate ligands and the lanthanide atoms build a chain, and the oxalate groups bridge the two chains to form the double-chain ladder-shaped structures. The one-dimensional double-chains are connected by intermolecular hydrogen bonds to form the two-dimensional network structure. Approximately 3.0×6.4 (A|°)2 rhombus channels exist in the seven compounds {[Ln(oda)(H2O)x]2(ox)}n, so they can be used as gas-storage materials.The amide-type compound, N,N'-bis(p-methoxyphenyl)-3-oxapentanediamide (L), was synthesized by oxydiacetic acid, and the reaction of lantanide nitrate with L produced nine complexes Ln(NO3)3·2L, of which two single crystals, Pr(NO3)3·2L and Nd(NO3)3·2L, suitable for X-ray crystallographic analysis were obtained. The X-ray crystal structures of the two compounds show that each ligand in compounds was tridentate coordination to form two stable planar five-membered chelate rings. One nitrate group coordinated bidentately with lanthanum atoms, and the other two groups were uncoordinated and balanced the charge. The hydrogen bonds in the compounds linked molecules to form a tri-dimensional network structure.
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