Crystal structure, Hirshfeld analysis and electrochemical properties of poly[diaquabis[μ₆-2-cyano-2-(oxidoimino)acetato]copper(II)disodium]

The title compound, [Na 2 Cu(C 3 N 2 O 3 ) 2 (H 2 O) 2 ] n , is a three-dimensional coordination polymer composed of divalent copper-centered complex anions, linked by sodium and water molecules. The copper(II) ion adopts a distorted octahedral coordination geometry, defined by two nitrogen atoms from oxime groups and two oxygen atoms from carboxylate groups, originating from two trans -oriented, doubly deprotonated residues of 2-cyano-2-(hydroxyimino)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.