Lanthanide–alkali metals–oxalates coordination polymers: Synthesis and structures of [Nd(C2O4)1.5(H2O)3] · 2H2O, Nd(C2O4)(CH3COO)(H2O), KLn(C2O4)2(H2O)4 (Ln = Y, Tb)

Two new lanthanide–oxalates coordination polymers, [Nd(C2O4)1.5(H2O)3] · 2H2O 1, Nd(C2O4)(CH3COO)(H2O) 2, and two new lanthanide–alkali–oxalates coordination polymers KY(C2O4)2(H2O)43, KTb(C2O4)2(H2O)44, have been synthesized under hydrothermal conditions and their structures were determined by single-crystal X-ray diffraction. Structural analysis shows that the two-dimensional (2D) layer structure of complex 1 is built up by the linkages of lanthanide atoms and the oxygen atoms of the bischelating oxalate ligands. In complex 2, for introducing of acetate groups, a 3D network with parallelogram channels (6.3 × 9.4 Å) of complex 2 was obtained. The 3D structures of complexes 3 and 4 contain a channel filled with lattice water molecules, and the potassium atoms are located in the framework.