Plutonium tetrafluoride

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Plutonium tetrafluoride [1]
Plutonium Tetrafluoride PuF4 from Hanford Site (cropped).jpg
A sample of plutonium tetrafluoride produced at the Hanford Site during the Cold War [2] [3]
Kristallstruktur Uran(IV)-fluorid.png
Names
IUPAC name
Plutonium(IV) fluoride
Other names
Plutonium tetrafluoride
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/4FH.Pu/h4*1H;/q;;;;+4/p-4
    Key: USCBBUFEOOSGAJ-UHFFFAOYSA-J
  • F[Pu](F)(F)F
Properties
PuF4
Molar mass 320 g/mol
Appearancereddish-brown monoclinic crystals
Density 7.1 g/cm3
Melting point 1,027 °C (1,881 °F; 1,300 K)
Structure
Monoclinic, mS60
C12/c1, No. 15
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Plutonium(IV) fluoride is a chemical compound with the formula PuF4. This salt is generally a brown solid but can appear a variety of colors depending on the grain size, purity, moisture content, lighting, and presence of contaminants. [4] [5] Its primary use in the United States has been as an intermediary product in the production of plutonium metal for nuclear weapons usage. [3]

Contents

Formation

Plutonium(IV) fluoride is produced in the reaction between plutonium dioxide (PuO2) or plutonium(III) fluoride (PuF3) with hydrofluoric acid (HF) in a stream of oxygen (O2) at 450 to 600 °C. The main purpose of the oxygen stream is to avoid reduction of the product by hydrogen gas, small amounts of which are often found in HF. [6]

PuO2 + O2 + 4 HF → PuF4 + O2 + 2 H2O
4 PuF3 + O2 + 4 HF → 4 PuF4 + 2 H2O

Laser irradiation of plutonium hexafluoride (PuF6) at wavelengths under 520 nm causes it to decompose into plutonium pentafluoride (PuF5) and fluorine; if this is continued, plutonium(IV) fluoride is obtained. [7]

Properties

In terms of its structure, solid plutonium(IV) fluoride features 8-coordinate Pu centers interconnected by doubly bridging fluoride ligands. [8]

Reaction of plutonium tetrafluoride with barium, calcium, or lithium at 1200 °C give Pu metal: [4] [5] [3]

PuF4 + 2 Ba → 2 BaF2 + Pu
PuF4 + 2 Ca → 2 CaF2 + Pu
PuF4 + 4 Li → 4 LiF + Pu
Plutonium tetrafluoride sample with example of one color illustrated through reference to a color standard Plutonium tetrafluoride color square.jpg
Plutonium tetrafluoride sample with example of one color illustrated through reference to a color standard

Related Research Articles

The actinide or actinoid series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. The actinide series derives its name from the first element in the series, actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide.

<span class="mw-page-title-main">Neptunium</span> Chemical element with atomic number 93 (Np)

Neptunium is a chemical element; it has symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. It is named after Neptune, the planet beyond Uranus in the Solar System, which uranium is named after. A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons. Neptunium metal is silvery and tarnishes when exposed to air. The element occurs in three allotropic forms and it normally exhibits five oxidation states, ranging from +3 to +7. Like all actinides, it is radioactive, poisonous, pyrophoric, and capable of accumulating in bones, which makes the handling of neptunium dangerous.

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

Chlorine pentafluoride is an interhalogen compound with formula ClF5. This colourless gas is a strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C4v symmetry, as confirmed by its high-resolution 19F NMR spectrum. It was first synthesized in 1963.

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

Beryllium fluoride is the inorganic compound with the formula BeF2. This white solid is the principal precursor for the manufacture of beryllium metal. Its structure resembles that of quartz, but BeF2 is highly soluble in water.

<span class="mw-page-title-main">Cobalt(III) fluoride</span> Chemical compound

Cobalt(III) fluoride is the inorganic compound with the formula CoF3. Hydrates are also known. The anhydrous compound is a hygroscopic brown solid. It is used to synthesize organofluorine compounds.

<span class="mw-page-title-main">Silver(II) fluoride</span> Chemical compound

Silver(II) fluoride is a chemical compound with the formula AgF2. It is a rare example of a silver(II) compound - silver usually exists in its +1 oxidation state. It is used as a fluorinating agent.

Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a strong Lewis acid and a component of the superacid fluoroantimonic acid, formed upon mixing liquid HF with liquid SbF5 in 1:1 ratio. It is notable for its strong Lewis acidity and the ability to react with almost all known compounds.

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

Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula HF. It is a very poisonous, colorless gas or liquid that dissolves in water to yield an aqueous solution termed hydrofluoric acid. It is the principal industrial source of fluorine, often in the form of hydrofluoric acid, and is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers, e.g. polytetrafluoroethylene (PTFE). HF is also widely used in the petrochemical industry as a component of superacids. Due to strong and extensive hydrogen bonding, it boils at near room temperature, much higher than other hydrogen halides.

<span class="mw-page-title-main">Hexafluorosilicic acid</span> Octahedric silicon compound

Hexafluorosilicic acid is an inorganic compound with the chemical formula H
2SiF
6. Aqueous solutions of hexafluorosilicic acid consist of salts of the cation and hexafluorosilicate anion. These salts and their aqueous solutions are colorless.

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

Zirconium(IV) fluoride describes members of a family inorganic compounds with the formula (ZrF4(H2O)x. All are colorless, diamagnetic solids. Anhydrous Zirconium(IV) fluoride' is a component of ZBLAN fluoride glass.

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

Selenium tetrafluoride (SeF4) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.

<span class="mw-page-title-main">Manganese(IV) fluoride</span> Chemical compound

Manganese tetrafluoride, MnF4, is the highest fluoride of manganese. It is a powerful oxidizing agent and is used as a means of purifying elemental fluorine.

<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 isotope of plutonium is needed to avoid premature ignition of low-mass nuclear weapon designs by neutrons produced by spontaneous fission of plutonium-240.

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

Germanium tetrafluoride (GeF4) is a chemical compound of germanium and fluorine. It is a colorless gas.

<span class="mw-page-title-main">Neptunium(VI) fluoride</span> Chemical compound

Neptunium(VI) fluoride (NpF6) is the highest fluoride of neptunium, it is also one of seventeen known binary hexafluorides. It is a volatile orange crystalline solid. It is relatively hard to handle, being very corrosive, volatile and radioactive. Neptunium hexafluoride is stable in dry air but reacts vigorously with water.

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">Hafnium tetrafluoride</span> Chemical compound

Hafnium tetrafluoride is the inorganic compound with the formula HfF4. It is a white solid. It adopts the same structure as zirconium tetrafluoride, with 8-coordinate Hf(IV) centers.

<span class="mw-page-title-main">Protactinium(V) fluoride</span> Chemical compound

Protactinium(V) fluoride is a fluoride of protactinium with the chemical formula PaF5.

Neptunium compounds are compounds containing the element neptunium (Np). Neptunium has five ionic oxidation states ranging from +3 to +7 when forming chemical compounds, which can be simultaneously observed in solutions. It is the heaviest actinide that can lose all its valence electrons in a stable compound. The most stable state in solution is +5, but the valence +4 is preferred in solid neptunium compounds. Neptunium metal is very reactive. Ions of neptunium are prone to hydrolysis and formation of coordination compounds.

References

  1. ↑ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, pp. 4–76, ISBN   0-8493-0594-2
  2. ↑ Pfeiffer, Martin (March 3, 2019). "FOI 2019-00371.Loaded powder pan at RMC line". Pfeiffer Nuclear Weapon and National Security Archive. Retrieved May 23, 2019.
  3. 1 2 3 United States Department of Energy (1997). Linking Legacies: Connecting the Cold War Nuclear Weapons Production Processes to Their Environmental Consequences (PDF). Washington D.C.: United States Department of Energy. pp. 184, passim.
  4. 1 2 Baldwin, Charles E.; Navratil, James D. (1983-05-19). "Plutonium Process Chemistry at Rocky Flats". In Carnall, William T.; Choppin, Gregory R. (eds.). Plutonium Chemistry. ACS Symposium Series. Vol. 216. AMERICAN CHEMICAL SOCIETY. pp. 369–380. doi:10.1021/bk-1983-0216.ch024. ISBN   9780841207721.
  5. 1 2 Christensen, Eldon L.; Grey, Leonard W.; Navratil, James D.; Schulz, Wallace W. (1983-05-19). "Present Status and Future Directions of Plutonium Process Chemistry". In Carnall, William T.; Choppin, Gregory R. (eds.). Plutonium Chemistry. ACS Symposium Series. Vol. 216. AMERICAN CHEMICAL SOCIETY. pp. 349–368. doi:10.1021/bk-1983-0216.ch023. ISBN   9780841207721. OSTI   6781635.
  6. ↑ Gmelins Handbuch der anorganischen Chemie , System Nr. 71, Transurane, Teil C, pp. 104–107.
  7. ↑ 4670239,Rabideau, Sherman W.&Campbell, George M.,"Photochemical preparation of plutonium pentafluoride",issued 1987-06-02
  8. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  9. ↑ Pfeiffer, Martin (March 3, 2019). "PuF4 Pics ORO 2019 00475-FN Final Response 20190312_Page_07_Image_0001". Pfeiffer Nuclear Weapon and National Security Archive. Retrieved May 23, 2019.
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