Two new coordination polymers, [(Cu-2(o-HPIDC)(2)(H2O)(2)](n) (1) and {[Nd(p-HPIDC)(ox)(0.5)(H2O)]center dot 2H(2)O}(n) (2) (o-H3PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid, p-H3PIDC = 2-(pyridine-4-yl)-1H-imidazole-4,5-dicarboxylic acid, H(2)ox = oxalic acid), have been synthesized under hydrothermal conditions and characterized by elemental and thermogravimetric analyses (TGA), infrared spectroscopy, and single-crystal X-ray diffraction. In 1, o-HPIDC2- ligands link Cu(II) centers into infinite 1-D chains that are stabilized by hydrogen bonds and pi center dot center dot center dot pi stacking interactions into a 3-D supramolecular architecture. In 2, ox(2-) ligands link the 2-D [Nd(p-HPIDC)](n) layers into a (4 center dot 8(2))(4 center dot 8(5)) 3-D network structure featuring two pairs of left-handed and right-handed helical chains. TGA of 1 and 2 are presented. In addition, the fluorescence properties of 2 have been studied in the solid state at room temperature.