Pseudo-merohedrally twinned praseodymium hexacyanoferrate(III) tetrahydrate

Abstract

Crystals of the title compound, diaquahexa-mu-cyano-ferrate(III)praseodymium(III) dihydrate, Pr[Fe(CN)6]\ub74H2O or [PrFe(CN)6(H2O)2]\ub72H2O, are twinned with three components. The Pr atom is coordinated by eight atoms, viz. six N and two symmetry-related water O atoms. The Pr polyhedron (Pr has site symmetry m2m, Wyckoff position 4c) is linked to an FeC6 octahedron (Fe located on a site with imposed 2/m symmetry, Wyckoff position 4b) through N atoms, forming an infinite array. The second (symmetry independent) water molecule lies on a mirror plane, is not included in coordination and is weakly hydrogen bonded to N atoms