Inorganic Chemistry, Vol.54, No.20, 9826-9832, 2015
From WCl6 to WCl2: Properties of Intermediate Fe-W-Cl Phases
Phenomenological studies of WCl6 reduction with transition metal powders M = Mn, Fe, and Co have been recently reported. These reactions involve a series of reductive intercalation steps of M atoms into layered tungsten chloride arrangements, followed by exsolution of MCl2. In the series M = Fe, the presence of divalent iron is evidenced for FexWCl6, FeW2Cl10, Fe2W2Cl10, and (Fe,W)Cl-2 by Mossbauer spectroscopy. Magnetic properties are reported. Bonding characteristics between tungsten atoms in edge-sharing [W2Cl10](n-) bioctahedra reveal that a double bond can be addressed to FeW2Cl10. A similar situation appears for Fe2W2Cl10, due to the localized and thus nonbonding character of the two electrons in the delta orbitals of this compound.