Reactions of Manganese(II) Fluoride in the Superacidic Systems HF/SbF5 and HF/GeF4 – Crystal Structure of Mn(SbF6)2 and Vibrational Spectra of MnGeF6

Mn(SbF₆)₂ was prepared from MnF₂ and SbF₅ in aHF (anhydrous HF) and single crystals were obtained from the respective solution. The compound crystallises in the triclinic space group P 1 (No. 2) with a = 517.3(2) pm, b = 554.9(2) pm, c = 888.2(2) pm, α = 73.98(3)°, β = 89.17(2)°, γ = 62.54(2)° and Z = 1. MnGeF₆ was prepared from MnF₂ and GeF₄ in aHF and by metathetical reaction between solutions of K₂GeF₆ in aHF and Mn(AsF₆)₂ in aHF. Attempt to isolate Mn(GeF₅)₂ prepared by metathetical reaction between solutions of XeF₅GeF₅ in aHF and Mn(AsF₆)₂ in aHF failed, although some slight evidences for its existence were obtained. Vibrational data of MnGeF₆ are in agreement with lowering of the symmetry of GeF₆^2– from O_h to C_3i because of the site symmetry effects.