Reactions of manganese(II) fluoride in the superacidic systems HF/SbF5 andHF/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 singl e crystals were obtained from the respective solution. The compound crystal lises in the triclinic space group P (1) over bar (No.2) with a = 517.3(2)p m, b = 554.9(2) pm, c = 888.2(2) pin, alpha = 73.98(3)degrees, beta = 89.17 (2)degrees, gamma = 62.54(2)degrees and Z = 1. MnGeF6 was prepared from MnF 2 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 m etathetical reaction between solutions of XeF5GeF5 in allF and Mn(AsF6)(2) in allF failed, although some slight evidences for its existence were obtai ned. Vibrational data of MnGeF6 are in agreement with lowering of the symme try of GeF62- from O-h to C-3i because of the site symmetry effects.