On the XeF+/H2O System: Synthesis and Characterization of the Xenon (II) Oxide Fluoride Cation, FXeOXeFXeF+ (PREPRINT)
Journal article preprint,
AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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The reported synthesis of the H2OF cation as a product of the oxidative fluorination of H2O by XeFPnF6 Pn As, Sb in HF solution has been reinvestigated. The system exhibits complex equilibria, producing two new XeII compounds, Xe3OF3PnF6 and H3OPnF62XeF2, refuting the original claim for the synthesis of the H2OF cation. Both compounds have been isolated and characterized by vibrational spectroscopy and single-crystal X-ray diffraction. The X-ray crystal structures of the Xe3OF3PnF6 salts contain the Z-shaped FXeOXeFXeF cation, which represents the first example of an isolated XeII oxide fluoride. The crystal structure of the H3OAsF62XeF2 adduct contains XeF2 molecules that interact with the H3O cations. The vibrational assignments for the Xe3OF3 cation have been made with the aid of quantum-chemical calculations and were confirmed by sup 18O-enrichment, while the assignments for H3OAsF62XeF2 were confirmed by 2D- and sup 18O-enrichment. Quantum-chemical calculations have also been carried out for H3OnXeF2 n 14, and have been used to interpret the X-ray crystal structure and vibrational spectra of H3OAsF62XeF2. The energy-minimized geometries and vibrational frequencies for HOF and H2OF have been calculated, further disproving the original report of the H2OF cation. Both FXeOH and FXeOH2 have also been computed and are viable intermediates in the proposed equilibria between XeF and H2O that lead to the Xe3OF3 cation.
- Organic Chemistry
- Physical Chemistry
- Atomic and Molecular Physics and Spectroscopy