catena-Poly[[(diaqua­zinc)-μ-3-carb­oxy­pyrazine-2-carboxyl­ato-κ⁴N¹,O²;N⁴,O³] nitrate]

The crystal structure of the title compound, {[Zn(C₆H₃N₂O₄)(H₂O)₂]NO₃}_n, is built of zigzag cationic chains propagating in [010] with nitrate anions located in the space between the chains. The Zn^II ion is coordinated by N and O atoms of two symmetry-related ligands in equatorial sites, and by two water O atoms at the axial sites of a distorted octa­hedron. One carboxyl­ate group of the ligand remains protonated, serving as a donor in a short intra­molecular O—H...O hydrogen bond. The coordinated water mol­ecules are donors and the nitrate O atoms act as acceptors in a network of O—H...O hydrogen bonds.