Xenon(IV)–Carbon Bond of [C₆F₅XeF₂]⁺; Structural Characterization and Bonding of [C₆F₅XeF₂][BF₄], [C₆F₅XeF₂][BF₄]·2HF, and [C₆F₅XeF₂][BF₄]·nNCCH₃(n= 1, 2); and the Fluorinating Properties of [C₆F₅XeF₂][BF₄]

Abstract

The [C6F5XeF2](+) cation is the only example of a Xe(IV)-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 (129)Xe, (19)F, and (11)B NMR spectra of [C6F5XeF2][BF4] in aHF are reported and compared with the (19)F NMR spectrum of C6F5IF2, and all previously unreported J((129)Xe-(19)F) and J((19)F-(19)F) couplings were determined. The long-term solution stabilities of [C6F5XeF2][BF4] were investigated by (19)F 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).

Nature of the XeVI−N Bonds in F6XeNCCH3and F6Xe(NCCH3)2and the Stereochemical Activity of Their Xenon Valence Electron Lone Pairs

“…ÀNb onds are presentlyk nown, [C 6 F 5 XeF 2 ·(NCCH 3 ) n ] + (n = 1o r2 ) [25] and F 2 OXeNCCH 3 . [26] The Lewis basicity and oxidative resistance of CH 3 CN (first adiabatic ionization potential, 12.194 AE 0.005 eV) [27] makes CH 3 CN an excellent ligand for the formation of Xe IV ÀNb onds.…”

On the nature of interactions in the F2OXe…NCCH3complex: Is there the Xe(IV)N bond?

“…Intermolecular (non‐covalent) interactions play important role in many aspects of chemistry. Interactions between noble gas atoms and molecules with electron donor–acceptor properties have been widely investigated recently . Bauzá and Frontera, proposed the new name for such non‐covalent interaction, based on the concept of σ‐hole bonding, aerogen bonding.…”

Aerogen Bonding Interaction: A New Supramolecular Force?

“…This structure is the first and unique example of a Xe IV N bond. Two further examples of Xe IV N donor–acceptor bonds have been reported,10 but involve a positively charged Xe IV moiety, i.e., [C 6 F 5 XeF 2 ] + . A partial view of the F 2 OXe⋅NCCH 3 crystal structure is shown in Figure 2.…”