The noble gases are the naturally occurring members of group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Under standard conditions, these elements are odorless, colorless, monatomic gases with very low chemical reactivity and cryogenic boiling points.
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.
Iodine pentafluoride is an interhalogen compound with chemical formula IF5. It is one of the fluorides of iodine. It is a colorless liquid, although impure samples appear yellow. It is used as a fluorination reagent and even a solvent in specialized syntheses.
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.
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.
Technetium hexafluoride or technetium(VI) fluoride (TcF6) is a yellow inorganic compound with a low melting point. It was first identified in 1961. In this compound, technetium has an oxidation state of +6, the highest oxidation state found in the technetium halides. In this respect, technetium differs from rhenium, which forms a heptafluoride, ReF7. Technetium hexafluoride occurs as an impurity in uranium hexafluoride, as technetium is a fission product of uranium (spontaneous fission in natural uranium, possible contamination from induced fission inside the reactor in reprocessed uranium). The fact that the boiling point of the hexafluorides of uranium and technetium are very close to each other presents a problem in using fluoride volatility in nuclear reprocessing.
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
2F+
3 cations.
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 isotope of 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.
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.
Molybdenum hexafluoride, also molybdenum(VI) fluoride, is the inorganic compound with the formula MoF6. It is the highest fluoride of molybdenum. It is a colourless solid and melts just below room temperature and boils in 34 °C. It is one of the seventeen known binary hexafluorides.
Chromyl fluoride is an inorganic compound with the formula CrO2F2. It is a violet-red colored crystalline solid that melts to an orange-red liquid.
Chromium hexafluoride or chromium(VI) fluoride (CrF6) is a hypothetical chemical compound between chromium and fluorine with the chemical formula CrF6. It was previously thought to be an unstable yellow solid decomposing at −100 °C, but this has been shown to be a misidentification of chromium pentafluoride, CrF5.
Nitrogen pentafluoride is a theoretical compound of nitrogen and fluorine with the chemical formula NF5. It is hypothesized to exist based on the existence of the pentafluorides of the atoms below nitrogen in the periodic table, such as phosphorus pentafluoride. Theoretical models of the nitrogen pentafluoride molecule are either a trigonal bipyramidal covalently bound molecule with symmetry group D3h, or [NF4]+F−, which would be an ionic solid.
Polonium hexafluoride is a possible chemical compound of polonium and fluorine and one of the seventeen known binary hexafluorides.
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.
Krypton(IV) fluoride is a hypothetical inorganic chemical compound of krypton and fluorine with the chemical formula KrF4. At one time researchers thought they had synthesized it, but the claim was discredited. The compound is predicted to be difficult to make and unstable if made. However, it is predicted to become stable at pressures greater than 15 GPa. Theoretical analysis indicates KrF4 would have an approximately square planar molecular geometry.
Americium hexafluoride is an inorganic chemical compound of americium metal and fluorine with the chemical formula AmF
6. It is still a hypothetical compound. Synthesis by fluorination of americium tetrafluoride was unsuccessfully attempted in 1990. A thermochromatographic identification in 1986 remains inconclusive. Calculations suggest that it may be distorted from octahedral symmetry.
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.
Einsteinium hexafluoride is a binary inorganic chemical compound of einsteinium and fluorine with the chemical formula EsF6. This is a hypothetical compound—its existence has been predicted theoretically, but the compound has yet to be isolated.
