Platinum hexafluoride is the chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Pt

Platinum

Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...

F₆

Fluorine

Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...

. 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

Xenon

Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...

 to form "XePtF₆," known as xenon hexafluoroplatinate

Xenon hexafluoroplatinate

Xenon hexafluoroplatinate is the name of the product of the reaction of platinum hexafluoride and xenon, in an experiment that proved the chemical reactivity of the noble gases...

. The discovery of this reaction in 1962 proved that noble gas

Noble gas

The noble gases are a group of chemical elements with very similar properties: under standard conditions, they are all odorless, colorless, monatomic gases, with very low chemical reactivity...

es form chemical compounds. Previous to the experiment with xenon, PtF₆ had been shown to react with oxygen to form (O₂)⁺(PtF₆)⁻, dioxygenyl hexafluoroplatinate

Dioxygenyl hexafluoroplatinate

Dioxygenyl hexafluoroplatinate is a compound with formula O2PtF6. It is a hexafluoroplatinate of the unusual dioxygenyl cation, O2+. It can be produced by the reaction of dioxygen with platinum hexafluoride:...

.

Synthesis

PtF₆ 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

Disproportionation

Disproportionation, also known as dismutation is used to describe a specific type of redox reaction in which a species is simultaneously reduced and oxidized so as to form two different products....

 of PtF₅. The required PtF₅ can be obtained by fluorinating PtCl₂:

2 PtCl₂ + 5 F₂ → 2 PtF₅ + 2 Cl₂

2 PtF₅ → PtF₆ + PtF₄

Other hexafluoride compounds

The neutral hexafluoride

Hexafluoride

A hexafluoride is a chemical compound with the general formula XF6. Sixteen elements are known to form stable hexafluorides. Nine of these elements are transition metals, three are actinides, and four are nonmetals or metalloids.- Physical properties :...

s of other elements are also volatile. These include osmium

Osmium

Osmium is a chemical element with the symbol Os and atomic number 76. Osmium is a hard, brittle, blue-gray or blue-blacktransition metal in the platinum family, and is the densest natural element. Osmium is twice as dense as lead. The density of osmium is , slightly greater than that of iridium,...

, iridium

Iridium

Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum family, iridium is the second-densest element and is the most corrosion-resistant metal, even at temperatures as high as 2000 °C...

, rhodium

Rhodium

Rhodium is a chemical element that is a rare, silvery-white, hard and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope, 103Rh. Naturally occurring rhodium is found as the free metal, alloyed...

, ruthenium

Ruthenium

Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element...

, rhenium

Rhenium

Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an average concentration of 1 part per billion , rhenium is one of the rarest elements in the Earth's crust. The free element has...

, tungsten

Tungsten

Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

, technetium

Technetium

Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature...

, and uranium

Uranium

Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

. All are aggressive oxidants. Uranium hexafluoride

Uranium hexafluoride

Uranium hexafluoride , referred to as "hex" in the nuclear industry, is a compound used in the uranium enrichment process that produces fuel for nuclear reactors and nuclear weapons. It forms solid grey crystals at standard temperature and pressure , is highly toxic, reacts violently with water...

 and tungsten hexafluoride are used in the nuclear and microelectronics industries, respectively. In the main group elements, sulfur

Sulfur

Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

, xenon

Xenon

Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...

, selenium

Selenium

Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

, and tellurium form isolable hexafluorides. Sulfur hexafluoride

Sulfur hexafluoride

Sulfur hexafluoride is an inorganic, colorless, odorless, and non-flammable greenhouse gas. has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but soluble in...

 is so extremely stable, perhaps due to steric effects

Steric effects

Steric effects arise from the fact that each atom within a molecule occupies a certain amount of space. If atoms are brought too close together, there is an associated cost in energy due to overlapping electron clouds , and this may affect the molecule's preferred shape and reactivity.-Steric...

, that it is used as an inert fluid in transformers. The analogues selenium hexafluoride

Selenium hexafluoride

Selenium hexafluoride is the inorganic compound with the formula SeF6. It is a colourless gas described as having a "repulsive" odor. It is not widely encountered and has no commercial applications.-Structure, preparation, and reactions:...

 and tellurium hexafluoride

Tellurium hexafluoride

Tellurium hexafluoride is the oldest known fluoride of tellurium. It is a colorless, highly toxic gas with an extremely unpleasant smell.-Preparation:...

 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.

General reading

• Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.