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

In the title compound, [CuK2(C3N2O3)2(H2O)3]n, the Cu2+ 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 H2O molecules. The crystal structure features O—H...O hydrogen bonds