[Li(XeF2)n](AF6) (A = P, As, Ru, Ir), the First Xenon(II) Compounds of Lithium. Synthesis, Raman Spectrum, and Crystal Structure of [Li(XeF2)3](AsF6)

The reactions between compounds of the type MAF6 (M = alkali metal; A = P, As, V, Ru, Ir, Sb, Nb, Ta) and xenon difluoride were studied in anhydrous hydrogen fluoride solvent. The coordination products [M­(XeF2)n]­AsF6 were only observed in the case of LiAF6 (A = P, As, Ru, Ir), and the crystal structure of [Li­(XeF2)3]­AsF6 was determined (monoclinic space group P21 with a = 6.901(9) Å, b = 13.19(2) Å, c = 6.91(1) Å, β = 91.84(2)°, and Z = 2). The coordination sphere of lithium is comprised of six F atoms. The compound series was also characterized by Raman spectroscopy.