Two new coordination polymers based on N-heterocyclic carboxylic acids
Two new coordination polymers, [(Cu2(o-HPIDC)2(H2O)2]n (1) and {[Nd(p-HPIDC)(ox)0.5(H2O)]·2H2O}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, H2ox = 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 π···π stacking interactions into a 3-D supramolecular architecture. In 2, ox2− ligands link the 2-D [Nd(p-HPIDC)]n layers into a (4·82)(4·85) 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.
