Xenon(IV)–Carbon Bond of [C6F5XeF2]+; Structural Characterization and Bonding of [C6F5XeF2][BF4], [C6F5XeF2][BF4]·2HF, and [C6F5XeF2][BF4]·nNCCH 3 (n = 1, 2); and the Fluorinating Properties of [C6F5XeF2][BF4]

The [C6F5XeF2]+ cation is the only example of a XeIV–C bond, which had only been previously characterized as its [BF4]− salt in solution by multi-NMR spectroscopy. The [BF4]− salt and its new CH3CN and HF solvates, [C6F5XeF2]­[BF4]·1.5CH3CN and [C6F5XeF2]­[BF4]·2HF, have now been synthesized and fully characterized in the solid state by low-temperature, single-crystal X-ray diffraction and Raman spectroscopy. Crystalline [C6F5XeF2]­[BF4] and [C6F5XeF2]­[BF4]·1.5CH3CN were obtained from CH3CN/CH2Cl2 solvent mixtures, and [C6F5XeF2]­[BF4]·2HF was obtained from anhydrous HF (aHF), where [C6F5XeF2]­[BF4]·1.5CH3CN is comprised of an equimolar mixture of [C6F5XeF2]­[BF4]·CH3CN and [C6F5XeF2]­[BF4]·2CH3CN. The crystal structures show that the [C6F5XeF2]+ cation has two short contacts with the F atoms of [BF4]− or with the F or N atoms of the solvent molecules, HF and CH3CN. The low-temperature solid-state Raman spectra of [C6F5XeF2]­[BF4] and C6F5IF2 were assigned with the aid of quantum-chemical calculations. The bonding in [C6F5XeF2]+, C6F5IF2, [C6F5XeF2]­[BF4], [C6F5XeF2]­[BF4]·CH3CN, [C6F5XeF2]­[BF4]·2CH3CN, and [C6F5XeF2]­[BF4]·2HF was assessed with the aid of natural bond orbital analyses and molecular orbital calculations. The 129Xe, 19F, and 11B NMR spectra of [C6F5XeF2]­[BF4] in aHF are reported and compared with the 19F NMR spectrum of C6F5IF2, and all previously unreported J(129Xe–19F) and J(19F–19F) couplings were determined. The long-term solution stabilities of [C6F5XeF2]­[BF4] were investigated by 19F NMR spectroscopy and the oxidative fluorinating properties of [C6F5XeF2]­[BF4] were demonstrated by studies of its reactivity with K­[C6F5BF3], Pn­(C6F5)3 (Pn = P, As, or Bi), and C6F5X (X = Br or I).