Uranium (III) chloride
Crystal structure | ||||||||||
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__ U 3+ __ Cl - | ||||||||||
Crystal system | ||||||||||
Space group |
P 6 3 / m (No. 176) |
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Lattice parameters |
a = 745.2 pm |
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Coordination numbers |
U [9], Cl [3] |
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General | ||||||||||
Surname | Uranium (III) chloride | |||||||||
other names |
Uranium trichloride |
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Ratio formula | UCl 3 | |||||||||
Brief description |
red crystals |
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External identifiers / databases | ||||||||||
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properties | ||||||||||
Molar mass | 344.39 g mol −1 | |||||||||
Physical state |
firmly |
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density |
5.50 g cm −3 |
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Melting point |
837 ° C |
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boiling point |
1657 ° C |
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Hazard and safety information | ||||||||||
Radioactive |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Uranium (III) chloride is a chemical compound consisting of the elements uranium and chlorine . It has the formula UCl 3 and belongs to the chloride class . It is an intermediate in spent nuclear fuel reprocessing.
presentation
There are two routes to the synthesis of uranium (III) chloride. On the one hand, it can be obtained by converting metallic uranium in a molten salt of sodium chloride and potassium chloride at 670-710 ° C.
Another possibility is by heating uranium (IV) chloride in a hydrogen atmosphere.
properties
At room temperature, uranium (III) chloride is a red, very hygroscopic , crystalline solid that is very soluble in water. UCl 3 is less stable than uranium (IV) chloride (UCl 4 ) because the +3 oxidation state is stabilized in acidic solution. In hydrochloric acid solution , UCl 3 is more stable than in water. Uranium (III) chloride melts at 837 ° C and boils at 1657 ° C, it has a density of 5.50 g / cm 3 .
Three hydrates of uranium (III) chloride are known:
- UCl 3 • 2 H 2 O • 2 CH 3 CN
- UCl 3 • 6 H 2 O
- UCl 3 · 7H 2 O
They are made by reducing uranium (IV) chloride in acetonitrile in the presence of water and propionic acid.
Crystal structure
The structure of uranium (III) chloride is the lead structure for a number of other compounds. In this the uranium atoms are surrounded by nine chlorine atoms each. The coordination polyhedron is a triple-capped, trigonal prism , as is often found in the later actinides and lanthanides . It crystallizes in the hexagonal crystal system in the space group P 6 3 / m (space group no. 176) with the lattice parameters a = 745 pm and c = 433 pm and two formula units per unit cell . Other compounds that crystallize in a uranium (III) chloride structure include neptunium (III) chloride , plutonium (III) chloride , americium (III) chloride , curium (III) chloride and antimony (III) - chloride .
use
Uranium (III) chloride is used to prepare various uranium metallocenes , for example in reactions with tetrahydrofuran (THF) and methylcyclopentadienyl sodium. It can also be used as a catalyst , for example in reactions between lithium aluminum hydride (LiAlH 4 ) and alkenes , for the synthesis of alkyl aluminum compounds.
Uranium (III) chloride is used in molten salts and plays a role in the reprocessing of spent nuclear fuel .
safety instructions
Similar to other soluble uranium compounds, UCl 3 is easily absorbed. It is highly toxic when inhaled and swallowed. In addition, there is a risk of accumulation in the human body, especially in the liver and kidneys . It is also toxic to aquatic organisms and can cause long-term damage to the aquatic world. Like all uranium compounds, it is radioactive . The activity depends on the isotopic composition of the uranium.
Individual evidence
- ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1969.
- ↑ a b David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Properties of the Elements and Inorganic Compounds, pp. 4-97.
- ^ Uranium (III) chloride at www.webelements.com.
- ↑ Entry on uranium compounds in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)
- ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry uranium compounds with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) , accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling.
- ↑ K. Serrano, P. Taxil, O. Dugne, S. Bouvet, E. Puech: "Preparation of Uranium by Electrolysis in Chloride Melt", in: J. Nucl. Mater. , 2000 , 282 (2-3), pp. 137-145 ( doi : 10.1016 / S0022-3115 (00) 00423-2 ).
- ↑ Ira Remsen: Inorganic Chemistry , New York: Henry Holt and Company, 1890.
- ^ Arthur Messinger Comey , Dorothy A. Hahn: A Dictionary of Chemical Solubilities: Inorganic. New York: The MacMillan Company, 1921.
- ↑ A. Mech, M. Karbowick, T. Lis: "Monomeric, Dimeric and Polymeric Structure of the Uranium Trichloride Hydrates", in: Polyhedron , 2006 , 25 (10), pp. 2083-2092 ( doi : 10.1016 / j. poly.2006.01.004 ).
- ^ Lester R. Morss, Norman M. Edelstein, Jean Fuger (Eds.): The Chemistry of the Actinide and Transactinide Elements: Vol. 3 , 2006 , Springer, ISBN 1-4020-3555-1 .
- ^ JG Brenna, RA Anderson, A. Zalkin: "Chemistry of Trivalent Uranium Metallocenes: Electron-Transfer Reactions with Carbon Disulfide. Formation of [(RC 5 H 4 ) 3 U] 2 [μ-η 1 , η 2 -CS 2 ] ", in: Inorg. Chem. , 1986 , 25 (11), pp. 1756-1760 ( doi : 10.1021 / ic00231a007 ).
- ^ JF Le Marechal, M. Ephritikhine, GJ Folcher: "Hydroalumination of olefins by the LiAlH 4 / UCl 4 system", in: Organomet. Chem. , 1986 , 309 (1-2), C1-C3 ( doi : 10.1016 / S0022-328X (00) 99589-5 ).
- ^ Y. Okamoto, P. Madden, K. Minato,: "X-Ray Diffraction and Molecular Dynamics Simulation Studies of Molten Uranium Chloride", in: J. Nucl. Mater. , 2005 , 344 (1-3), pp. 109-114; doi : 10.1016 / j.jnucmat.2005.04.026 .
- ^ Y. Okamoto, F. Kobayashi, T. Ogawa: “Structure and Dynamic Properties of Molten Uranium Trichloride”, in: J. Alloys Compd. , 1998 , 271-273 , pp. 355-358 ( doi : 10.1016 / S0925-8388 (98) 00087-5 ).
- ↑ Rosalie Bertell: "Gulf War Veterans and Depleted Uranium" , May 1999.
literature
- Ingmar Grenthe, Janusz Drożdżynński, Takeo Fujino, Edgar C. Buck, Thomas E. Albrecht-Schmitt, Stephen F. Wolf: Uranium , in: Lester R. Morss, Norman M. Edelstein, Jean Fuger (eds.): The Chemistry of the Actinide and Transactinide Elements , Springer, Dordrecht 2006; ISBN 1-4020-3555-1 , pp. 253-698 ( doi : 10.1007 / 1-4020-3598-5_5 ).