Krypton hexafluoride

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Krypton hexafluoride
Names
Other names
Krypton(VI) fluoride
Identifiers
Properties
F6Kr
Molar mass 197.788 g·mol−1
Appearanceclaimed to be white crystalline solid
Related compounds
Related compounds
Xenon hexafluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Krypton hexafluoride is an inorganic chemical compound of krypton and fluorine with the chemical formula KrF6. It is still a hypothetical compound. [1]

History

In 1933, Linus Pauling predicted [2] that the heavier noble gases would be able to form compounds with fluorine and oxygen. He also predicted the existence of krypton hexafluoride. [3] So far, out of all possible krypton fluorides, only krypton difluoride (KrF2) has been actually formed. It is a white crystalline solid that decomposes spontaneously at normal temperatures. [4] This fact leads to suggest that krypton hexafluoride is also an unstable compound.

Related Research Articles

<span class="mw-page-title-main">Noble gas</span> Group of low-reactive, gaseous chemical elements

The noble gases make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).

In chemistry, noble gas compounds are chemical compounds that include an element from the noble gases, group 18 of the periodic table. Although the noble gases are generally unreactive elements, many such compounds have been observed, particularly involving the element xenon.

Dioxygen difluoride is a compound of fluorine and oxygen with the molecular formula O2F2. It can exist as an orange-colored solid which melts into a red liquid at −163 °C (110 K). It is an extremely strong oxidant and decomposes into oxygen and fluorine even at −160 °C (113 K) at a rate of 4% per dayits lifetime at room temperature is thus extremely short. Dioxygen difluoride reacts vigorously with nearly every chemical it encounters (including ordinary ice) leading to its onomatopoeic nickname FOOF (a play on its chemical structure and its explosive tendencies).

<span class="mw-page-title-main">Xenon hexafluoride</span> Chemical compound

Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon that have been studied experimentally, the other two being XeF2 and XeF4. All known are exergonic and stable at normal temperatures. XeF6 is the strongest fluorinating agent of the series. It is a colorless solid that readily sublimes into intensely yellow vapors.

<span class="mw-page-title-main">Xenon difluoride</span> Chemical compound

Xenon difluoride is a powerful fluorinating agent with the chemical formula XeF
2
, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with water vapor, but is otherwise stable in storage. Xenon difluoride is a dense, colourless crystalline solid.

<span class="mw-page-title-main">Tungsten oxytetrafluoride</span> Chemical compound

Tungsten oxytetrafluoride is an inorganic compound with the formula WOF4. It is a colorless diamagnetic solid. The compound is one of many oxides of tungsten. It is usually encountered as product of the partial hydrolysis of tungsten hexafluoride.

<span class="mw-page-title-main">Krypton difluoride</span> Chemical compound

Krypton difluoride, KrF2 is a chemical compound of krypton and fluorine. It was the first compound of krypton discovered. It is a volatile, colourless solid at room temperature. The structure of the KrF2 molecule is linear, with Kr−F distances of 188.9 pm. It reacts with strong Lewis acids to form salts of the KrF+ and Kr
2
F+
3
cations.

<span class="mw-page-title-main">Plutonium hexafluoride</span> Chemical compound

Plutonium hexafluoride is the highest fluoride of plutonium, and is of interest for laser enrichment of plutonium, in particular for the production of pure plutonium-239 from irradiated uranium. This pure plutonium is needed to avoid premature ignition of low-mass nuclear weapon designs by neutrons produced by spontaneous fission of plutonium-240.

A hexafluoride is a chemical compound with the general formula QXnF6, QXnF6m−, or QXnF6m+. Many molecules fit this formula. An important hexafluoride is hexafluorosilicic acid (H2SiF6), which is a byproduct of the mining of phosphate rock. In the nuclear industry, uranium hexafluoride (UF6) is an important intermediate in the purification of this element.

<span class="mw-page-title-main">Iridium hexafluoride</span> Chemical compound

Iridium hexafluoride, also iridium(VI) fluoride, (IrF6) is a compound of iridium and fluorine and one of the seventeen known binary hexafluorides. It is one of only a few compounds with iridium in the oxidation state +6.

<span class="mw-page-title-main">Tetrafluoroammonium</span> Chemical compound

The tetrafluoroammonium cation is a positively charged polyatomic ion with chemical formula NF+
4
. It is equivalent to the ammonium ion where the hydrogen atoms surrounding the central nitrogen atom have been replaced by fluorine. Tetrafluoroammonium ion is isoelectronic with tetrafluoromethane CF
4
, trifluoramine oxide ONF
3
and the tetrafluoroborate BF
4
anion.

<span class="mw-page-title-main">Thionyl tetrafluoride</span> Chemical compound

Thionyl tetrafluoride, also known as sulfur tetrafluoride oxide, is an inorganic compound with the formula SOF4. It is a colorless gas.

Chromium pentafluoride is the inorganic compound with the chemical formula CrF5. It is a red volatile solid that melts at 34 °C. It is the highest known chromium fluoride, since the hypothetical chromium hexafluoride has not yet been synthesized.

Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding. Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others the highest oxidation states of oxides and fluorides are always equal.

<span class="mw-page-title-main">Radon compounds</span>

Radon compounds are compounds formed by the element radon (Rn). Radon is a member of the zero-valence elements that are called noble gases, and is chemically not very reactive. The 3.8-day half-life of radon-222 makes it useful in physical sciences as a natural tracer. Because radon is a gas at standard conditions, unlike its decay-chain parents, it can readily be extracted from them for research.

<span class="mw-page-title-main">Krypton tetrafluoride</span> Chemical compound

Krypton(IV) fluoride is a hypothetical inorganic chemical compound of krypton and fluorine with the chemical formula KrF4. At one time researchers though they made it, but the claim was discredited. The compound is predicted to be difficult to make and unstable if made. Theoretical analysis indicates KrF4 would have an approximately square planar molecular geometry.

Palladium hexafluoride is an inorganic chemical compound of palladium metal and fluorine with the chemical formula PdF6. It is reported to be a still hypothetical compound. This is one of many palladium fluorides.

<span class="mw-page-title-main">Xenon octafluoride</span> Chemical compound

Xenon octafluoride is a chemical compound of xenon and fluorine with the chemical formula XeF8. This is still a hypothetical compound. XeF8 is reported to be unstable even under pressures reaching 200 GPa.

Hexaoxygen difluoride is a binary inorganic compound of fluorine and oxygen with the chemical formula O6F2. The compound is one of many known oxygen fluorides.

<span class="mw-page-title-main">Molybdenum oxytetrafluoride</span> Chemical compound

Molybdenum oxytetrafluoride is the inorganic compound with the formula MoOF4. It is a white, diamagnetic solid. According to X-ray crystallography, it is a coordination polymer consisting of a linear chain of alternating Mo and F atoms. Each Mo center is octahedral, the coordination sphere being defined by oxide, three terminal fluorides, and two bridging fluorides. In contrast to this motif, tungsten oxytetrafluoride crystallizes as a tetramer, again with bridging fluoride ligands.

References

  1. Dixon, David A.; Wang, Tsang-Hsiu; Grant, Daniel J.; Peterson, Kirk A.; Christe, Karl O.; Schrobilgen, Gary J. (1 November 2007). "Heats of Formation of Krypton Fluorides and Stability Predictions for KrF4 and KrF6 from High Level Electronic Structure Calculations". Inorganic Chemistry . 46 (23): 10016–10021. doi:10.1021/ic701313h. ISSN   0020-1669. PMID   17941630 . Retrieved 28 March 2023.
  2. Williams, Jeffrey H. (28 September 2017). Crystal Engineering: How Molecules Build Solids. Morgan & Claypool Publishers. p. 4–1. ISBN   978-1-68174-625-8 . Retrieved 28 March 2023.
  3. Pauling, Linus (May 1933). "The Formulas of Antimonic Acid and the Antimonates". Journal of the American Chemical Society . 55 (5): 1895–1900. doi:10.1021/ja01332a016. ISSN   0002-7863 . Retrieved 28 March 2023.
  4. Burbank, R. D.; Falconer, W. E.; Sunder, W. A. (22 December 1972). "Crystal Structure of Krypton Difluoride at −80°C". Science . 178 (4067): 1285–1286. doi:10.1126/science.178.4067.1285. ISSN   0036-8075. PMID   17792123. S2CID   96692996 . Retrieved 28 March 2023.