Crystal structure of catena-poly[[gold(I)-μ-cyanido-[di-aqua-bis-(2-phenyl-pyrazine)-iron(II)]-μ-cyanido] dicyanidogold(I)].

In the title polymeric complex, {[Fe(CN)(2)(C(10)H(8)N(2))(2)(H(2)O)(2)][Au(CN)(2)]} (n) , the Fe(II) ion, which is located on a twofold rotation axis, has a slightly distorted FeN(4)O(2) octa-hedral geometry. It is coordinated by two phenyl-pyrazine mol-ecules, two water mol-ecules and two di-cyano-aurate anions, the Au atom also being located on a second twofold rotation axis. In the crystal, the coordinated di-cyano-aurate anions bridge the Fe(II) ions to form polymeric chains propagating along the b-axis direction. In the crystal, the chains are linked by O(water)-H⋯N(di-cyano-aurate anions) hydrogen bonds and aurophillic inter-actions [Au⋯Au = 3.5661†(3)†à ], forming layers parallel to the bc plane. The layers are linked by offset π-π stacking inter-actions [inter-centroid distance = 3.643†(3)†à ], forming a supra-molecular metal-organic framework.