Poly[μ-aqua-diaquabis­[μ-2-cyano-2-(oxidoimino)­acetato]­copper(II)dipotassium]

In the title compound, [CuK(2)(C(3)N(2)O(3))(2)(H(2)O)(3)](n), the Cu(2+) atom is in a distorted square-pyramidal coordination geometry. Two N atoms belonging to the oxime groups and two O atoms belonging to the carboxyl­ate groups of two trans-disposed doubly deprotonated residues of 2-cyano-2-(hy­droxy­imino)­acetic acid make up the basal plane and the apical position is occupied by the water mol­ecule. The neighboring Cu-containing moieties are linked into a three-dimensional framework by K—O and K—N contacts formed by two potassium cations with the carboxyl­ate and the oxime O atoms and the nitrile N atoms of the ligand. The environments of the K(+) cations are complemented to octa- and nona­coordinated, by K—O contacts with H(2)O mol­ecules. The crystal structure features O—H⋯O hydrogen bonds.