Synthesis and Characterization of [XeOXe]2+ in the Adduct-Cation Salt, [CH3CN- - -XeOXe- - -NCCH3][AsF6]2

Acetonitrile and [FXeOXe‐ ‐ ‐FXeF][AsF6] react at −60 °C in anhydrous HF (aHF) to form the CH3CN adduct of the previously unknown [XeOXe]2+ cation. The low‐temperature X‐ray structure of [CH3CN‐ ‐ ‐XeOXe‐ ‐ ‐NCCH3][AsF6]2 exhibits a well‐isolated adduct‐cation that has among the shortest Xe−N distances obtained for an sp‐hybridized nitrogen base adducted to xenon. The Raman spectrum was fully assigned by comparison with the calculated vibrational frequencies and with the aid of 18O‐enrichment studies. Natural bond orbital (NBO), atoms in molecules (AIM), electron localization function (ELF), and molecular electrostatic potential surface (MEPS) analyses show that the Xe−O bonds are semi‐ionic whereas the Xe−N bonds may be described as strong electrostatic (σ‐hole) interactions. A new xenon(II) oxide: The XeII oxide cation, [XeOXe]2+, has been synthesized at low‐temperature as its CH3CN adduct salt, [CH3CN‐ ‐ ‐XeOXe‐ ‐ ‐NCCH3][AsF6]2, and characterized by low‐temperature single‐crystal X‐ray diffraction and Raman spectroscopy. Computational methods were used to assess the bonding in [XeOXe]2+ and its adduct. The dication is the second example of a XeII oxide and is stabilized by CH3CN through σ‐hole type interactions.