Uranium tetrafluoride
Names | |
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IUPAC names
Uranium(IV) fluoride
Uranium tetrafluoride | |
Identifiers | |
3D model (
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ChemSpider | |
ECHA InfoCard
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100.030.142 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
UF4 | |
Molar mass | 314.02 g/mol |
Appearance | Green crystalline solid |
Density | 6.70 g/cm3, solid |
Melting point | 1,036 °C (1,897 °F; 1,309 K) |
Boiling point | 1,417 °C (2,583 °F; 1,690 K) |
Insoluble | |
Structure | |
Monoclinic, mS60
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C2/c, No. 15 | |
Hazards | |
GHS labelling: | |
Danger | |
H300, H330, H373, H411 | |
Flash point | Non-flammable |
Safety data sheet (SDS) | External MSDS |
Related compounds | |
Other anions
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Other cations
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Plutonium(IV) fluoride
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Related compounds
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Uranium hexafluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Uranium tetrafluoride is the
Production
UF4 is prepared from UO2 in a fluidized bed by reaction with HF. The UO2 is derived from mining operations. Around 60,000 tonnes per year are prepared in this way annually. A common impurity is UO2F2. UF4 is susceptible to hydrolysis as well.[1]
UF4 is formed by the reaction of UF6 with hydrogen gas in a vertical tube-type reactor. UF4 is less stable than the uranium oxides and reacts slowly with moisture at ambient temperature, forming UO2 and HF, the latter of which is very
of UF4 varies from about 2.0 g/cm3 to about 4.5 g/cm3 depending on the production process and the properties of the starting uranium compounds.A
Reactions
Uranium tetrafluoride reacts with fluorine, first to give uranium pentafluoride and then volatile UF6:
- 2 UF4 + F2 → 2 UF5
- 2 UF5 + F2 → 2 UF6
UF4 is reduced by magnesium to give the metal:[2]
- UF4 + 2 Mg → U + 2 MgF2
It is oxidized to UF5 at room temperature and then, at 100 °C, to the hexafluoride.
Structure
Like most metal fluorides, UF4 is a dense highly crosslinked inorganic polymer. As established by X-ray crystallography, the U centres are eight-coordinate with square antiprismatic coordination spheres. The fluoride centres are doubly bridging.[2][3]
Safety
Like all uranium salts, UF4 is
See also
- Praseodymium(IV) fluoride which has the same crystal structure
References of historical interest
- Booth, H. S.; Krasny-Ergen, W.; Heath, R. E. (1946). "Uranium Tetrafluoride". Journal of the American Chemical Society. 68 (10): 1969. .
References
- ^ ISBN 978-3527306732.
- ^ ISBN 978-0-08-037941-8.
- doi:10.1063/1.467963.
External links
- "Uranium Tetrafluoride". Appendix A of the PEIS (DOE/EIS-0269). Argonne National Laboratory. Archived from the original on 30 January 2016. Retrieved 22 November 2011.