Polymeric μ‐cyano‐di­cyano­nickelate(II)‐μ‐cyano‐trans‐bis­[N‐(2‐hydroxyethyl)ethyl­enedi­amine]­cadmium(II)

The title compound, catena‐poly­[[μ‐cyano‐1:2κ²C:N‐di­cyano‐1κ²C‐trans‐bis­[N‐(2‐hydroxy­ethyl)­ethane‐1,2‐di­amine‐2κ²N,N′]­cadmium(II)­nickel(II)]‐μ‐cyano‐1:2′κ²C:N], [CdNi(CN)₄(C₄H₁₂N₂O)₂], consists of alternating square‐planar Ni(CN)₄ fragments, formally dianionic, and Cd(hydet‐en)₂ moieties [hydet‐en is N‐(2‐hydroxy­ethyl)­ethyl­ene­di­amine], with the two bridging cyanide ligands in a mutually trans disposition at the Ni atom and cis at the Cd atom. The resulting one‐dimensional zigzag chain structure has the Ni atom on an inversion center, while the distorted octahedron centered on the Cd atom lies on a twofold axis. The polymer chains are connected into undulating sheets by weak interchain N—H⋯N, N—H⋯O and O—H⋯N hydrogen bonds, which are also present between successive sheets.