catena-Poly[potassium-di-μ-aqua-μ-4-(5-tetra-zolio)pyridine].

The title compound, K(C(6)H(4)N(5))(H(2)O)(2), was synthesized by hydro-thermal reaction of KOH with 4-(5-tetra-zolio)pyridine. The K atom has a distorted octa-hedral coordination environment and is coordinated by two axial N atoms from the organic ligand and by four water mol-ecules in the equatorial plane. The mol-ecules as a whole are located on crystallographic mirror planes; the K atom is also located on an inversion center. Both the water mol-ecules and the organic ligands act as bridges to link symmetrically the adjacent K atoms into polymeric chains parallel to the c axis. O-H⋯N hydrogen bonds involving the water O atoms and aromatic π-π inter-actions [centroid-centroid distance 3.80 (2) Å] between the pyridine and tetra-zole rings build up an infinite three-dimensional network.