[H(OXeF₂)_n][AsF₆] and [FXe^II(OXe^IVF₂)_n][AsF₆] (n = 1, 2): Examples of Xenon(IV) Hydroxide Fluoride and Oxide Fluoride Cations and the Crystal Structures of [F₃Xe---FH][Sb₂F₁₁] and [H₅F₄][SbF₆]·2[F₃Xe---FH][Sb₂F₁₁]

Abstract

The xenon(IV) hydroxide fluoride and oxide fluoride salts, [H(OXeF2)n][AsF6] and [FXe(II)(OXe(IV)F2)n][AsF6] (n = 1, 2), have been synthesized as the natural abundance and the (18)O- and (2)H-enriched salts and structurally characterized by low-temperature Raman spectroscopy. Quantum-chemical calculations have been used to arrive at vibrational assignments. The experimental vibrational frequencies and isotopic shift trends are reproduced by the calculated gas-phase frequencies at several levels of theory. The cation chain is limited to one or two OXeF2 subunits, which are oxygen-bridged and strongly ion-paired with the AsF6(-) anion. The reaction of XeOF2·xHF with a superacidic HF/SbF5 solvent mixture yielded crystals of [H5F4][SbF6]·2[XeF3·HF][Sb2F11], [XeF3·HF][Sb2F11], and [XeF3][SbF6]. The XeF3(+) cations of each salt are very similar, displaying T-shaped primary coordination of xenon to three fluorine atoms (AX3E2 VSEPR arrangement) and a secondary contact to the fluorine atom of HF in [H5F4][SbF6]·2[XeF3·HF][Sb2F11] and [XeF3·HF][Sb2F11] or to a fluorine atom of SbF6(-) in [XeF3][SbF6]. The secondary coordination spheres of xenon in [H5F4][SbF6]·2[XeF3·HF][Sb2F11] and [XeF3·HF][Sb2F11] are similar; however, the F3Xe---FH(+) cation of the latter salt is disordered. An additional contact between the XeF3(+) cation and the SbF6(-) anion in [H5F4][SbF6]·2[XeF3·HF][Sb2F11] presumably alters the crystal packing sufficiently to give an ordered F3Xe---FH(+) cation, a rare example in which HF is coordinated to a noble gas. The latter compound also provides the first documentation of the H5F4(+) acidium ion, which forms a zigzag F4-chain terminated by SbF6(-) anions. Enthalpies and Gibbs free energies of reaction obtained from Born-Fajans-Haber thermochemical cycles support the proposed decomposition pathways.

Mixed Noble‐Gas Compounds of Krypton(II) and Xenon(VI); [F5Xe(FKrF)AsF6] and [F5Xe(FKrF)2AsF6]

“…result in corrugated layers that are parallel to the ac-plane and are stacked along the b-axis of the unit cell. TheX e---F H secondary bonds of [F 5 Xe(FH)PnF 6 ]( As, 2.656(2) ;Sb, 2.6501(10) )are similar,but are significantly greater than those of [F 3 Xe(FH)Sb 2 F 11 ]( 2.462(2) ) [25] and [FXe(FH)Sb 2 F 11 ]( 2.359(4) ), [26] in accordance with the lower Lewis acidity of [XeF 5 ] + relative to [XeF 3 ] + and [XeF] + . [10,13,19] Ab rief description of the crystal structure of the nonisotypic antimony analogue (4)isprovided in the Supporting Information along with associated X-ray data (Figures S7 and S8, Table S3).…”

Mixed Noble‐Gas Compounds of Krypton(II) and Xenon(VI); [F5Xe(FKrF)AsF6] and [F5Xe(FKrF)2AsF6]

“…Forschungsartikel result in corrugated layers that are parallel to the ac-plane and are stacked along the b-axis of the unit cell. TheX e---F H secondary bonds of [F 5 Xe(FH)PnF 6 ]( As, 2.656(2) ;Sb, 2.6501(10) )are similar,but are significantly greater than those of [F 3 Xe(FH)Sb 2 F 11 ]( 2.462(2) ) [25] and [FXe(FH)Sb 2 F 11 ]( 2.359(4) ), [26] in accordance with the lower Lewis acidity of [XeF 5 ] + relative to [XeF 3 ] + and [XeF] + . [10,13,19] Ab rief description of the crystal structure of the nonisotypic antimony analogue (4)isprovided in the Supporting Information along with associated X-ray data (Figures S7 and S8, Table S3).…”

Anorganische Chemie 2013

“…Dieses ist isoelektronisch zu IF3 und weist daher ebenso eine T‐förmige Struktur auf. Mit Arsenpentafluorid entstehen aus XeOF2·xHF die somit erstmals isolierten und charakterisierten Xenon(IV)hydroxyfluoride [H(OXeIVF2)n][AsF5] und Xenon(II)oxidfluoride [FXeII (OXeIVF2)n][AsF5] (n = 1, 2) 125…”