X-ray and Raman studies of single crystals of CsSbF₆

Abstract

Crystals of CsSbF₆ belong to the rhombohedral space groupR¯3-C ²_3i witha=7.904(1)andc=8.261(1) Å,V=446.95 ų,Z=3,D _c=4.11 gcm⁻³. The antimony atom is surrounded by six fluorine atoms in a nearly perfect octahedral configuration with Sb-F 1.875(9) Å, while 12 fluorine atoms surround the cesium atom with closest contact 3.116 Å. Polarized Raman spectra of single crystals of CsSbF₆ have been obtained, and it is shown that these results can be interpreted in terms of a unimolecular rhombohedral structure. The small distortion from an octahedral arrangement for the SbF ⁻₆ group is clearly reflected in the spectra. The Raman results are in better agreement with the space groupR¯3m-D ⁵_3d than withR¯3-C ²_3i , but this conclusion must be regarded with caution since the two features in the vibrational spectra of CsSbF₆ which can be used to distinguish between the two structures are weak and ill-defined.