Vibrational Spectra and Structure of XeO2F2

The Raman spectra of liquid and solid XeO₂F₂ and the infrared spectrum of XeO₂F₂ in an argon matrix at liquid‐helium temperature are reported. They are interpreted in terms of $C_{\text{2υ}}$ molecular symmetry which can be associated with a molecule of pseudobipyramidal structure, where the two F atoms are axial to the Xe and the two O atoms with a lone electron pair are equatorial. The vibrational spectra support the existence of primarily monomeric XeO₂F₂ molecules in the liquid state and quite probably in the solid. The nine fundamentals assigned are: 848 ${\mathrm{(\nu }}_1{\text{), 490 (ν}}_2{\text{), 333 (ν}}_3{\text{), 198 (ν}}_4{\text{), 224 (ν}}_5{\text{), 905 (ν}}_6{\text{), 324 (ν}}_7{\text{), 585 (ν}}_8)$ , and ${\text{317 (ν}}_9)$ .