Syntheses and Characterizations of the Mixed Noble-Gas Compounds, [FKrII FXeII F][AsF6 ]⋅0.5 KrII F2 ⋅2 HF, ([KrII 2 F3 ][AsF6 ])2 ⋅XeIV F4 , and XeIV F4 ⋅KrII F2.

Reaction of [XeF][AsF6 ] with excess KrF2 at -78 °C in anhydrous HF (aHF) solvent has yielded the first mixed KrII /XeII noble-gas compound, [FKrFXeF][AsF6 ] ⋅0.5 KrF2 ⋅2 HF, a salt of the [FKrFXeF]+ cation. The potent oxidative fluorinating properties of KrII fluoride species resulted in oxidation of XeII to XeIV in aHF at -60 °C to form the mixed KrII /XeIV cocrystals, ([Kr2 F3 ][AsF6 ])2 ⋅XeF4 and XeF4 ⋅KrF2 . Further decomposition at 22 °C resulted in oxidation of XeIV to XeVI to give the recently reported KrII /XeVI complexes, [F5 Xe(FKrF)n ][AsF6 ] (n=1, 2), [F5 Xe][AsF6 ], and a new KrII /XeVI complex, [(F5 Xe)2 (μ-FKrF)(AsF6 )2 ], which was characterized by low-temperature (LT) Raman spectroscopy. The [FKrFXeF][AsF6 ]⋅0.5 KrF2 ⋅2 HF, ([Kr2 F3 ][AsF6 ])2 ⋅XeF4  , and XeF4 ⋅KrF2 compounds were characterized by LT Raman spectroscopy and single-crystal X-ray diffraction. Quantum-chemical calculations were used to assess the bonding in [FKrFXeF]+ , [Kr2 F3 ]+ , and [Xe2 F3 ]+ and to aid in their vibrational assignments.