Solution Multi-NMR and Raman Spectroscopic Studies of Thermodynamically Unstable XeO4. The First 131Xe NMR Study of a Chemically Bound Xenon Species †

Xenon tetroxide is thermodynamically unstable, decomposing explosively in the gas phase and in the solid state. A modified and more detailed description of the procedure for the preparation of XeO(4) and its solutions is provided. Xenon tetroxide dissolves in SO(2)ClF, BrF(5), and HF solvents, giving solutions that are kinetically stable up to -30 degrees C. The preparation of kinetically stable XeO(4) solutions lays the groundwork for the solution chemistry of XeO(4) and for the extension of the presently limited chemistry of xenon(VIII). The (129)Xe and (17)O NMR spectra of XeO(4) were observed for the first time, and the tetrahedral symmetry of XeO(4) allowed for the observation of a surprisingly narrow (131)Xe resonance, the first (131)Xe NMR study of a xenon compound. A variable temperature and variable field strength study of the spin-lattice relaxation times for (129)Xe and (131)Xe show that the spin-rotation and the quadrupolar relaxation mechanisms, respectively, are dominant. The Raman spectrum of XeO(4) in anhydrous HF solvent confirms the absence of significant solvent-solute interactions.