Platinum hexafluoride is the chemical compound with the formula PtF6. It is a dark-red volatile solid that forms a red gas. The compound is a unique example of platinum in the 6+ oxidation state. With only four d-electrons, it is paramagnetic with a triplet ground state.
PtF6 is a strong oxidant and a strong fluorinating agent that is best known for its reaction with xenon to form "XePtF6," known as xenon hexafluoroplatinate. The discovery of this reaction in 1962 proved that noble gases form chemical compounds. Previous to the experiment with xenon, PtF6 had been shown to react with oxygen to form (O2)+(PtF6)−, dioxygen hexafluoroplatinate.
was first prepared by reaction of fluorine with platinum metal. This route remains the method of choice.
- Pt + 3 F2 → PtF6
PtF6 can also be prepared by disproportionation of PtF5. The required PtF5 can be obtained by fluorinating PtCl2
- PtCl2 + 2.5 F2 → PtF5 + Cl2
- 2 PtF5 → PtF6 + PtF4
Other hexafluoride compounds
The neutral hexafluorides
of other elements are also volatile. These include osmium
, and uranium
. All are aggressive oxidants. Uranium hexafluoride
and tungsten hexafluoride
are used in the nuclear and microelectronics industries, respectively. In the main group elements, sulfur
, and tellurium
form isolable hexafluorides. Sulfur hexafluoride
is so extremely stable, perhaps due to steric effects
, that it is used as an inert fluid in transformers. The analogues selenium hexafluoride
and tellurium hexafluoride
are, however, strongly reactive.
Like the hexafluorides of Mo, Tc, Ru, Rh, W, Re, Os, and Ir, PtF6 is octahedral in both the solid state and in the gaseous state. The Pt-F bond lengths are 185 picometers.
- Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.