Xenon Difluoride and the Nature of the Xenon-Fluorine Bond

Abstract

Xenon reacts with fluorine to form XeF(2) which can be isolated before it reacts with fluorine to form XeF(4). The linear configuration of XeF(2) with the 2.00-A bond length and the vibrational force constants support the assignment of 10 electrons to the valence shell of xenon. Similar arguments support the assignment of 12 and 14 valence electrons respectively to xenon in XeF(4) and XeF(6).

The First Compound Containing a Metal Center in a Homoleptic Environment of XeF2 Molecules

“…This situation is also evident from the Raman spectroscopy. In free XeF 2 the totally symmetric (n 1 ) stretching mode is at 497 cm À1 , [6] where charge at fluorine ligands of 0.5 e 0 is expected. [7] When XeF 2 is coordinated to metal ion it is distorted and the band at 497 cm À1 is replaced by two bands.…”

“…Although the latter is shorter than the former (see Figure 2), owing to the electrostatic attraction of oppositely charged [AsF 6 ] À ion and Ca 2+ ion, higher Lewis basicities are expected for the fluorine atoms from XeF 2 molecules. This situation is evident from the elongation of the bridging XeÀF bonds and the contraction of the terminal XeÀF bonds, while the AsÀF11 bridging distance (170.9(9) pm) does not show significant elongation compared to the terminal AsÀF bonds (ranging from 167.9 to 170.3 pm).…”

“…This situation means that the Lewis basicity of the fluorine atoms in the XeF 2 molecule strongly depends on the cation to which XeF 2 is already coordinated. The XeF 2 molecules, in this compound, favor the formation of a crystal-structure network, in which there are monodentate [AsF 6 ] À groups compensating for the overall charge of the network.…”

“…[2,3] Metal centers in all the compounds of this type are coordinated simultaneously by XeF 2 molecules and [AF 6 ] À ions (A = As, Sb, P). The important feature of the compound described herein, Ca 2 (XeF 2 ) 9 (AsF 6 ) 4 , is that for the first time one calcium center is coordinated to XeF 2 molecules only (a homoleptic center) while the second is coordinated to XeF 2 molecules and [AsF 6 ] À ions. The reaction between Ca(AsF 6 ) 2 and XeF 2 , in anhydrous HF (aHF) as a solvent, yields two compounds: [Ca(XeF 2 ) n ]-(AsF 6 ) 2 ; n = 4 and 2.5.…”

Oxidation of ruthenium and iridium metal by XeF2 and crystal structure determination of [Xe2F3][RuF6]∙XeF2 and [Xe2F3][MF6] (M = Ru, Ir)

“…For solid XeF 2 the band at 497 cm -1 is characteristic. 27 The bands at 506 cm Figure 2. In the spectrum shown on the Figure 2a ( + cations are oriented roughly perpendicularly to each other.…”