Poly[[hexa-μ-cyanido-manganese(II)-iron(III)] pentahydrate]

The structure of the title compound, MnII[FeIII(CN)6] 2/3·5H2O, features a face-centered cubic -Mn - NC - Fe- framework with both Mn and Fe having site symmetry m m. Since one-third of the [Fe(CN)6] 3- units are missing for a given formula in order to maintain charge neutrality, each Mn atom around such a vacancy is coordinated not only by the N atoms of the CN groups but also by the O atoms of the ligand water mol-ecules. In addition to ligand water mol-ecules, two types of non-coordinated water mol-ecules, so-called zeolitic water mol-ecules, exist in the inter-stitial sites of the -Mn - NC - Fe- framework. The positions of the O atoms of the zeolitic water mol-ecules are fixed by the linkage via hydrogen bonds between ligand water and zeolitic water mol-ecules. The structure is related to a recently reported rubidium manganese hexa-cyano-ferrate. Site occupancy factors for Fe, C, N are 0.67; for two O atoms the value is 0.83 and for one O atom is 0.17. © 2008 International Union of Crystallography.