Abstract: | A novel neutral polymer, {Co2(C7H3NO4)2(H2O)4]·2H2O}n, was hydrothermally synthesized using pyridine‐2,5‐dicarboxylate (2,5‐PDC2?) as the organic linker. It features a two‐dimensional layer structure constructed from one‐dimensional {Co(2,5‐PDC)2]2?}n chains interlinked by Co(H2O)4]+ units. The two CoII cations occupy special positions, sitting on inversion centres. Each 2,5‐PDC2? anion chelates to one CoII cation via the pyridine N atom and an O atom of the adjacent carboxylate group, and links to two other CoII cations in a bridging mode via the O atoms of the other carboxylate group. In this way, the 2,5‐PDC2? ligand connects three neighbouring CoII centres to form a two‐dimensional network. The two‐dimensional undulating layers are linked by extensive hydrogen bonds to form a three‐dimensional supramolecular structure, with the uncoordinated solvent molecules occupying the interlamellar region. |