The Xenon Difluoride Complexes XeF₂ · XeOF₄; XeF₂ · XeF₆ · AsF₅ and XeF₂ · 2 XeF₆ · 2 AsF₅ and Their Relevance to Bond Polarity and Fluoride Ion Donor Ability of XeF₂ and XeF₆

Abstract

Xenon difluoride forms a 1:1 complex with XeOF4 (m.p. 29°C) which is isostructural with XeF2 · IF5. The unit cell is tetragonal with a = 7.56(2), c = 11.36(3) Å, V = 647 Å3, z = 4. RAMAN data prove it to be a molecular complex, the structure of which is compatible with appreciable bond polarity in XeF2. Similar interactions of XeF2 with the XeF+5 cation are indicated by the RAMAN spectra of the complexes which XeF2 forms with [XeF5]+[AsF6]−. The spectrum of the 1:2 complex indicates that the XeF2 molecule is undistorted but the spectrum of the 1:1 complex suggests that the XeF2 molecule is distorted by interaction with XeF+5 ions. The occurrence of molecular XeF2 in the XeF+5AsF6 lattice confirms the superiority of XeF6 to XeF2 as a fluoride ion donor.

A Raman spectroscopic study of the XeOF4/XeF2 system and the X-ray crystal structure of α-XeOF4·XeF2

“…Bond lengths and bond angles for XeOF 4 ÁXeF 2 are listed in Table 2. The unit cell parameters for aXeOF 4 ÁXeF 2 are in good agreement with those obtained from the Xray powder diffraction study (a = 7.56(2), c = 11.36(3) Å , V = 647 Å 3 , Z = 4, 20 8C) [22].…”

“…3) has been previously reported [22]. The present work provides more detailed assignments and descriptions of the vibrational modes based on a knowledge of the crystal structure.…”

“…The Ng-F stretching frequencies of main-group cation complexes with NgF 2 show frequency shift patterns that are similar to those of the metal cation complexes (vide supra). The compound, XeOF 4 ÁXeF 2 , was first synthesized by Bartlett et al who reported its Raman spectrum (À10 8C) and X-ray powder diffraction pattern [22]. The Raman spectrum was assigned as the sum of the component of XeF 2 and XeOF 4 spectra.…”

How Far Can One Push the Noble Gases Towards Bonding?: A Personal Account

“…, XeF 2 , XeF 4 , XeF 6 , XeOF 4 , XeO 3 , and KrF 2 were synthesized and characterized [14,15]. Xe was the most studied element among the group 18 elements due to its loosely bonded electrons and numerous reports appeared in the literature about species like XeF 2 , XeF 4 , XeF 6 , XeOF 4 , XeO 3 , and many more [16,17,18,19,20,21]. Even radioactive Rn was successfully employed to make compounds, RnF 2 and [RnF][Sb 2 F 11 ] being two examples among them [22].…”

The Raman spectra of solid xenon tetrafluoride and its adduct with xenon difluoride

“…XeF,-XeF,, however, is but one of a number of adducts formed by xenon difluoride in which the XeF, molecule appears to be essentially indistinguishable from the molecule in crystalline xenon difluoride, viz XeF,.IF, [7], XeF,*XeOF, [8], and XeF, . (2 [XeF:] [AsF,]) [8]. The ordered close-packed lattices of these compound stem from coulombic intermolecular interactions involving the polar Xe6+ -Fdbonds (or IS+-F6-bonds).…”