is a powerful fluorinating agent
with the chemical formula , and one of the most stable xenon compounds
. Like most covalent
it is moisture sensitive. It decomposes
on contact with light
or water vapour. Xenon difluoride is a dense, white crystalline
solid. It has a nauseating odour but low vapor pressure
. It has a strong characteristic infrared
doublet at 550 cm<sup>−1</sup>
and 556 cm<sup>−1</sup>.
Xenon difluoride is a linear
molecule with an Xe–F bond length of 197.73±0.15 pm
in the vapor phase, and 200 pm in the solid phase. The packing arrangement in solid shows that the fluorine atoms of neighbouring molecules avoid the equatorial region of each molecule. This agrees with the prediction of VSEPR
theory, which predicts that there are 3 pairs of non-bonding electrons around the equatorial region of the xenon atom.
At high pressures, novel, non-molecular forms of xenon difluoride can be obtained. Under a pressure of ~50 GPa
, transforms into a semiconductor consisting of units linked in a two-dimensional structure, like graphite
. At even higher pressures, above 70 GPa, it becomes metallic, forming a three-dimensional structure containing units.
Synthesis proceeds by the simple formula:
- Xe + F<sub>2</sub> →......