Syntheses and Structures of Xenon Trioxide Alkylnitrile Adducts

The potent oxidizer and highly shock‐sensitive binary noble‐gas oxide XeO3 interacts with CH3CN and CH3CH2CN to form O3XeNCCH3, O3Xe(NCCH3)2, O3XeNCCH2CH3, and O3Xe(NCCH2CH3)2. Their low‐temperature single‐crystal X‐ray structures show that the xenon atoms are consistently coordinated to three donor atoms, which results in pseudo‐octahedral environments around the xenon atoms. The adduct series provides the first examples of a neutral xenon oxide bound to nitrogen bases. Raman frequency shifts and Xe−N bond lengths are consistent with complex formation. Energy‐minimized gas‐phase geometries and vibrational frequencies were obtained for the model compounds O3Xe(NCCH3)n (n=1–3) and O3Xe(NCCH3)n⋅[O3Xe(NCCH3)2]2 (n=1, 2). Natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), electron localization function (ELF), and molecular electrostatic potential surface (MEPS) analyses were carried out to further probe the nature of the bonding in these adducts. Xenon trioxide forms stable 1:1 and 1:2 adducts with CH3CN and CH3CH2CN, which were characterized by Raman spectroscopy and X‐ray crystallography. Computational studies show that the Xe‐ ‐ ‐N interactions are essentially electrostatic. The amphoteric Lewis acid/base nature of XeO3 influences the geometries of these adducts in the solid state where the structural units interact through Xe=O‐ ‐ ‐Xe bridges.