Ba(SbF6)2·5XeF2:  First Xenon(II) Compound with Barium. Synthesis, Vibrational Spectra, and Crystal Structure

The reaction between Ba(SbF6)2 and excess XeF2 in anhydrous HF at room temperature yields the white solid Ba(SbF6)2·5XeF2 after the excess XeF2 and the solvent have been removed under vacuum. Ba(SbF6)2·5XeF2 crystallizes in the monoclinic space group C2/m, with a = 13.599(6) Å, b = 12.086(4) Å, c = 9.732(5) Å, β = 134.305(6)°, V = 1144.7 (8) Å3, and Z = 2. The coordination sphere of each barium atom consists of 12 fluorine atoms. The structure consists of alternating layers of Ba(SbF6)2·XeF2 and 4 XeF2 molecules. The Ba atoms in the Ba(SbF6)2·XeF2 layer are in a nearly rhombic-net array and are linked with trans F-bridging ligands of SbF6 -. A XeF2 molecule is placed in the center of each rhombus of the Ba2+ array so that its symmetry axis is perpendicular to the plane of the Ba(SbF6)2·XeF2 layer. This layer is linked to its neighbors by a layer of centrosymmetric XeF2 molecules. Raman spectra are in accord with all XeF2 molecules being symmetrical.