Crystal structure of [{[Ni(C(10)H(24)N(4))][Ni(CN)(4)]}·2H(2)O]( n ), a one-dimensional coordination polymer formed from the [Ni(cyclam)](2+) cation and the [Ni(CN)(4)](2–) anion

The asymmetric unit of the title compound, catena-poly[[[(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ(4) N (1),N (4),N (8),N (11))nickel(II)]-μ-cyanido-κ(2) N:C-[bis­(cyanido-κC)nickel(II)]-μ-cyanido-κ(2) C:N] dihydrate], {[Ni(2)(CN)(4)(C(10)H(24)N(4))]·2H(2)O]( n ) or [{[Ni(C(10)H(24)N(4))][Ni(CN)(4)]}·2H(2)O]( n ), consists of a pair of crystallographically non-equivalent macrocyclic cations and anions. The nickel(II) ions (all with site symmetry [Image: see text] ) are coordinated by the four secondary N atoms of the macrocyclic ligands, which adopt the most energetically stable trans-III conformation, and the mutually trans N atoms of the tetra­cyano­nickelate anion in a slightly tetra­gonally distorted NiN(6) octa­hedral coordination geometry. The [Ni(CN)(4))](2–) anion exhibits a bridging function, resulting in the formation of parallel polymeric chains running along the [1 [Image: see text] 0] direction. The water mol­ecules of crystallization play a pivotal role in the three-dimensional supra­molecular organization of the crystal. Acting as acceptors, they form N—H⋯O(w) (w = water) hydrogen bonds with the secondary amino groups of the macrocycles, forming layers oriented parallel to the (001) plane. At the same time, as donors, they inter­act with the non-coordinated cyano groups of the anion via O(w)—H⋯N(c) (c = cyanide) hydrogen bonds, giving two-dimensional layers oriented parallel to the (100) plane and thus generating a three-dimensional network.