Poly[aqua­[μ₃-4-carb­oxy-2-(pyridin-4-yl)-1H-imidazole-5-carboxyl­ato-κ⁵N¹,O⁵:N³,O⁴:N²]nickel(II)]

The water-coordinated Ni²⁺ cation in the title compound, [Ni(C₁₀H₅N₃O₄)(H₂O)]_n, assumes an octa­hedral NiN₃O₃ coord­ination mode and is N,O-chelated by two deprotonated 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarb­oxy­lic acid (HPyImDC²⁻) ligands, forming a layer structure extending in the bc plane. The chains are arranged along the b-axis direction, forming a layer structure extending in the bc plane. O—H...O hydrogen bonding between the layers results in the formation of a three-dimensional supra­molecular framework. The structure is isotypic with the Zn analogue [Li et al. (2009). Cryst. Growth Des. 6, 3423–3431].