is a noble gas compound
with the formula
XeF<sub>6</sub> and the highest of the three binary fluorides of xenon
, the other two being XeF<sub>2</sub>
. All are exergonic
and stable at normal temperatures. XeF<sub>6</sub> is the strongest fluorinating agent of the series. At room temperature, it is a colorless solid that readily sublimes into intensely yellow vapors.
Xenon hexafluoride can be prepared by long-term heating of XeF<sub>2</sub> at about 300°C and pressure 6 MPa (60 atmospheres).
as catalyst, however, this reaction can proceed at 120°C even in xenon-fluorine molar ratios as low as 1:5.
The structure of XeF<sub>6</sub> required several years to establish in contrast to the cases of and . In the gas phase the compound is monomeric
theory predicts that due to the presence of six fluoride ligands and one lone pair of electrons the structure lacks perfect octahedral symmetry
, and indeed electron diffraction
combined with high-level calculations indicate that the compound's point group is C<sub>3v</sub>
. The calculated energy for the point group O<sub>h</sub>
is only insignificantly higher, indicating that the minimum on the energy surface is very shallow. Konrad Seppelt
, an authority on noble gas and fluorine chemistry, says, "the structure is... Read More