Ultraviolet Photolysis Studies on XeO₄ in Noble‐Gas and F₂ Matrices and the Formation and Characterization of a New Xe^VIII Oxide, (η²‐O₂)XeO₃

Abstract

The photolytic behavior of the thermochemically unstable xenon(VIII) oxide XeO4 was investigated by UV irradiation in noble-gas and F2 matrices. Photolysis of Xe(16) O4 or Xe(18) O4 in noble-gas matrices at 365 nm yielded XeO3 and a new xenon(VIII) oxide, namely, (η(2) -O2 )XeO3 , which, along with XeO4 , was characterized by matrix-isolation IR spectroscopy and quantum-chemical calculations. Calculations of the UV spectrum showed that the photodecomposition is induced by an n→σ* transition, but the nature of the excitation differs when different light sources are used. There is strong evidence for the formation of mobile (1) D excited O atoms in the case of excitation at 365 nm, which led to the formation of (η(2) -O2 )XeO3 by reaction with XeO4 . Matrix-isolation IR spectroscopy in Ne and Ar matrices afforded the natural-abundance xenon isotopic pattern for the ν3 (T2 ) stretching mode of Xe(16) O4 , and (18) O enrichment provided the (16) O/(18) O isotopic shifts of XeO4 and (η(2) -O2 )XeO3 .

Polyfluorides and Neat Fluorine as Host Material in Matrix‐Isolation Experiments

“…With λ =(365±10) nm irradiation the peroxo species (η 2 ‐O 2 )XeO 3 with xenon in its highest oxidation state +VIII and XeO 3 are formed, see Figure 8. Remarkably, xenon oxofluorides or binary xenon fluorides were not formed from XeO 4 in neat fluorine, although in contrast to the oxides the fluorides of xenon are exothermic 12. 66…”

“…Very recently,t he photochemistry of XeO 4 wasi nvestigated in neon, argon, and neat fluorine. [12] XeO 4 decomposes upon broad band UV irradiation into Xe, O 2 ,a nd traces of O 3 . With l = (365 AE 10) nm irradiation the peroxos pecies (h 2 -O 2 )XeO 3 with xenon in its highest oxidation state + VIII and XeO 3 were formed.…”

“…This has proven that in neat fluorine matrices fluorides in higher oxidation states can be formed. Very recently, the photochemistry of XeO 4 was investigated in neon, argon, and neat fluorine 12. XeO 4 decomposes upon broad band UV irradiation into Xe, O 2 , and traces of O 3 .…”

“…Xenon forms three binary fluorides (i.e., XeF 2 , XeF 4 , XeF 6 ), and oxides (i.e., XeO 2 , XeO 3 , XeO 4 ) and various oxoflourides. Very recently the structure and photochemistry of XeO 4 , the only binary Xe VIII compound, was investigated in neon, argon, and neat fluorine 12. It decomposes upon broad‐band UV irradiation into Xe, O 2 , and traces of O 3 .…”

A new database and benchmark of the bond energies of noble‐gas‐containing molecules

“…With the advent of experimental and computational techniques, noble gas chemistry has been flourishing in recent years with many new observed and predicted noble‐gas‐containing molecules. [ 14–34 ] Computational study has played an integral role in noble gas chemistry. Predictions on the stability and spectral properties of noble‐gas molecules have not only provided directions for their experimental synthesis but also helped in confirming the identities of new such molecules.…”