Poly[deca-mu(2)-cyanido-dicyanidobis(mu(2)-ethylenediamine)bis(ethylenediamine)tricadmium(II)dicobalt(III)]: a two-dimensional coordination polymer.

The title coordination polymer, Cd(3)Co(2)(CN)(12)(C(2)H(8)N(2))(4), has an infinite two-dimensional network structure. The asymmetric unit is composed of two crystallographically independent Cd(II) atoms, one of which is located on a twofold rotation axis. There are two independent ethylenediamine (en) ligands, one of which bis-chelates to the Cd atom that sits in a general position, while the other bridges this Cd atom to that sitting on the twofold axis. The Cd atom located on the twofold rotation axis is linked to four equivalent Co(III) atoms via cyanide bridges, while the Cd atom that sits in a general position is connected to three equivalent Co(III) atoms via cyanide bridges. In this way, a series of trinuclear, tetranuclear and pentanuclear macrocycles are linked to form a two-dimensional network structure lying parallel to the bc plane. In the crystal structure, these two-dimensional networks are linked via N-H...N hydrogen bonds involving an en NH(2) H atom and a cyanide N atom, leading to the formation of a three-dimensional structure. This coordination polymer is only the second example involving a cyanometallate where the en ligand is present in both chelating and bridging coordination modes.