Poly[diaquatris(μ6-4,6-dioxo-1,4,5,6-tetra-hydro-1,3,5-triazine-2-carboxylato)tripotassium]

The asymmetric unit of the title compound, [K3(C4H2N3O4)3(H2O)2] n , contains two potassium cations (one in general position, one located on a twofold rotation axis), one and a half oxonate anions (the other half generated by twofold symmetry) and one water mol-ecule. As a result of the twofold symmetry, one H atom of the symmetric anion is statistically occupied. Both potassium cations are surrounded by eight oxygen atoms in the form of distorted polyhedra. Adjacent cations are inter-connected by oxygen bridges, generating layers parallel to (100). The aromatic ring system of the oxonate anions link these layers into a network structure. The crystal packing is stabilized by N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, three of which are bifurcated. In addition, inter-molecular π-π stacking inter-actions exist between neighboring aromatic rings with a centroid-centroid distance of 3.241 (2) Å.