Dixenon cation

The only example of xenon in a fractional oxidation state, +, is the bright emerald green paramagnetic dixenon cation, Xe [12185-20-5]. Mixtures of xenon and fluorine gases react spontaneously with tiquid antimony pentafluoride in the dark to form solutions of XeF+ Sb2 F, in which Xe is formed as an iatermediate product that is subsequently oxidized by fluorine to the XeF+ cation (83). Spectroscopic studies have shown that xenon is oxidized at room temperature by solutions of XeF+ ia SbF solvent to give the XE cation (84). 

Divalent metal ions, reversible binding, 38 153 Dixenon cation, 46 68 Dizinc enzymes, 40 351-354 DMA, see Dicarbomethoxy acetylene DMAD complexes, see Dicarboxymethoxy dithiolene complexes DMAE, see Dimethylarsinoylethanol DMF, reduction potentials, 33 57 DMSO, see Dimethylsulfoxide DNA... 

A transient green colour in solutions of XeF2— XeF4—SbFs 5) reported many years ago has recently been identified with the dixenon (+1) cation, [Xe2]+ 6 7). This ion had been observed previously only in gaseous xenon as the product of excited atom collisions. The dixenon cation is a product of either oxidation of... 

Formation of the dixenon cation can also be monitored by the appearance of a band at 123 cm-1 in the Raman spectrum. A striking resemblance to the dark green isoelectronic [I2] is to be noted with strong absorptions at 370-400 and 737-800 nm in the visible and we = 114-116 cm-1 in the resonance Raman spectrum of... 

A major part of the chemistry of xenon fluorides and oxide fluorides is associated with their reactions with fluoride donors and acceptors to produce a variety of cations and anions. The known species are summarized in Scheme 1. In addition, there are a number of more unusual entities, notably the dixenon cation [Xe2]+ and [Xe03X] (X = F, Cl, or Br). The preparations, structures, and chemistry of these species was comprehensively reviewed in 1984 (12), so only developments since 1979 are covered in this present account. 

Finding a Xe—Xe bond was unexpected, but there was a further surprise in store. In 2007, Seppelt and coworkers reported that the green [Xe2] in SbFs solution turns blue in the presence of xenon at pressures between 30 and 40 bar, i.e. when a substantial proportion of liquid xenon is present [16]. The process is reversible when the pressure is lowered. Crystals of the blue product could not be obtained, however, and characterization of this new species was reliant upon spectroscopy and comparison with the results obtained from quantum mechanical calculations. These data indicate the formation of a linear cation 1X04] (Oooh). [Xe Xe-Xe Xe], which could be seen as a dixenon adduct of [Xc2]. The calculated structure gives a central Xe—Xe bond length of 3.190 A (even longer than in [Xe2] ) and two terminal distances of 3.529 A. 

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