Crystal structure, Hirshfeld analysis and electrochemical properties of poly[di-aqua-bis-[μ6-2-cyano-2-(oxido-imino)-acetato]-copper(II)disodium].

The title compound, [Na2Cu(C3N2O3)2(H2O)2] n , is a three-dimensional coordination polymer composed of divalent copper-centered complex anions, linked by sodium and water mol-ecules. The copper(II) ion adopts a distorted octahedral coordination geometry, defined by two nitro-gen atoms from oxime groups and two oxygen atoms from carboxyl-ate groups, originating from two trans-oriented, doubly deprotonated residues of 2-cyano-2-(hy-droxy-imino)-acetic acid. The axial Cu-O bonds are much longer than the equatorial Cu-O and Cu-N bonds due to the Jahn-Teller effect. Each complex anionic unit is linked to four neighboring anions via Cu-O bonds, forming a two-dimensional anionic network parallel to the bc plane.