catena-Poly[[[μ-cyanido-1:2κ(2) C:N-tricyanido-1κ(3) C-bis(ethylenediamine)-2κ(4) N,N′-copper(II)iron(II)]-μ-cyanido-κ(2) C:N-[bis(ethylenediamine-κ(2) N,N′)copper(II)]-μ-cyanido-κ(2) N:C] 4.5-hy­drate]

The asymmetric unit of the title compound, {[Cu(2)Fe(CN)(6)(C(2)H(8)N(2))(4)]·4.5H(2)O}(n), consists of two [Cu(C(2)H(8)N(2))(2)](2+) cations, one [Fe(CN)(6)](4−) anion, four water mol­ecules and a half water mol­ecule that lies on a twofold rotation axis. The Fe(II) atom is coordinated by six C atoms from three terminal and three doubly bridging CN(−) ligands. The bridging CN(−) ligands connect the anion to a five-coordinate [Cu(C(2)H(8)N(2))(2)](2+) cation and to two symmetry-related six-coordinate [Cu(C(2)H(8)N(2))(2)](2+) cations, forming a one-dimensional polymer in the ab plane. Inter­molecular hydrogen bonds connect the polymer units into a three-dimensional network.