(IUCr) Crystallography Journals Online

Acta Cryst. (2008). E64, i11-i12 [ doi:10.1107/S1600536807068869 ]

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

T. Matsuda, H. Tokoro, M. Shiro, K. Hashimoto and S. Ohkoshi

Abstract: The structure of the title compound, Mn^II[Fe^III(CN)₆]_2/3·5H₂O, features a face-centered cubic -Mn-NC-Fe- framework with both Mn and Fe having site symmetry m $\overline{3}$ 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 molecules. In addition to ligand water molecules, two types of non-coordinated water molecules, so-called zeolitic water molecules, exist in the interstitial sites of the -Mn-NC-Fe- framework. The positions of the O atoms of the zeolitic water molecules are fixed by the linkage via hydrogen bonds between ligand water and zeolitic water molecules. The structure is related to a recently reported rubidium manganese hexacyanoferrate. 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.

Online 9 January 2008