Uranium(III) chloride

From Wikipedia, the free encyclopedia

Uranium(III) chloride
IUPAC name Uranium(III) chloride
Other names Uranium chloride,
Uranium trichloride
Identifiers
CAS number [10025-93-1]
Properties
Molecular formula Cl3U
Molar mass 344.39 g mol-1
Appearance Green crystalline solid
Density 5.500 g/cm³, liquid
Melting point

837 °C, 1110 K, 1539 °F
Boiling point

1657 °C, 1930 K, 3015 °F
Solubility in water Soluble
Structure
Hybridisation Tricapped trigonal prismatic
Hazards
Flash point Non-flammable
Autoignition
temperature		 Non-flammable
Related compounds
Related compounds Uranium(IV) chloride,
Uranium(V) chloride,
Uranium(VI) chloride
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Uranium(III) chloride , UCl3, is a chemical compound that contains the earth metal uranium and chlorine. UCl3 is used mostly to reprocess spent nuclear fuel. Uranium(III) chloride is synthesized various ways from uranium(IV) chloride; however, UCl3 is less stable than UCl4.

Contents

[edit] Preparation

There are two ways to synthesize uranium(III) chloride. The following processes describe how to produce uranium(III) chloride.

(1) In a mixture of NaCl-KCl at 670-710 °C, add uranium tetrachloride with uranium metal.

3UCl4 + U → 4UCl3[1]

(2) Heat uranium(IV) chloride in hydrogen gas.

2UCl4 + H2 → 2UCl3 + 2HCl[2]

[edit] Properties

In the uranium(III) chloride molecule, three chlorine atoms are bonded around a uranium center in a tricapped trigonal prismatic configuration. A tricapped trigonal prismatic configuration has a configuration number of nine.

Uranium(III) chloride is a green crystalline solid at room temperature. UCl3 melts at 837 °C and boils at 1657°C. Uranium(III) chloride has a density of 5500 kg/m³ or 5.500 g/cm³.

Its composition by weight:

Chlorine: 30.84%
Uranium: 69.16%

Its formal oxidative states:

Chlorine: −1
Uranium: +3

Uranium(III) chloride is very soluble in water and is also very hygroscopic. UCl3 is more stable in a solution of hydrochloric acid.[3]

[edit] Uses

[edit] Reagent

Uranium(III) chloride is used in reactions with tetrahydrofuran (THF) and sodium methylcyclopentadiene to prepare various uranium metallocene complexes.[4]

[edit] Catalyst

Uranium(III) chloride is used as a catalyst during reactions between lithium aluminium hydride (LiAlH4) and olefins to produce alkyl aluminate compounds.[5]

[edit] Molten form

The molten form of uranium(III) chloride is a typical compound in pyrochemical processes as it is important in the reprocessing of spent nuclear fuels.[6]UCl3 is usually the form that uranium takes as spent fuel in electrorefining processes.[7],[6]

[edit] Hydrates

There are three hydrates of uranium(III) chloride:

  1. UCl3.2H2O.2CH3CN
  2. UCl3.6H2O
  3. UCl3.7H2O

Each are synthesized by the reduction of uranium(IV) chloride in methylcyanide (acetonitrile), with specific amounts of water and propionic acid.[8]

[edit] Precautions

While there are no long-term data on the toxic effects thas UCl3, it is important to minimize exposure to this compound when possible.

Similar to other uranium compounds that are soluble, UCl3 is likely absorbed into the blood through the alveolar pockets of the longs within days of exposure. Exposure to uranium(III) chloride leads to toxicity of the renal system.[9]

Wikimedia Commons has media related to:

[edit] References

  1. ^ Serrano, K.; Taxil, P.; Dugne, O.; Bouvet, S.; Puech, E. J. Nucl. Mater. 2000, 282, 137–145.
  2. ^ Remsen, Ira. Inorganic Chemistry. New York: Henry Holt and Company, 1890.
  3. ^ Comey, Arthur M. and Hahn, Dorothy A. A Dictionary of Chemical Solubilities: Inorganic. New York: The MacMillan Company, 1921.
  4. ^ Brenna, J.G.; Anderson, R.A.; Zalkin, A. Inorg. Chem. 1986, 25, 1756–1760.
  5. ^ Le Marechal, J.F.; Ephritikhine, M.; Folcher, G. J. Organomet. Chem. 1986, 309, C1–C3
  6. ^ a b Okamoto, Y.; Madden, P.; Minato, K. J. Nucl. Mater. 2005, 344, 109–114.
  7. ^ Okamoto, Y.; Kobayashi, F.; Ogawa, T. J. Alloys Compd. 1998, 271, 355–358.
  8. ^ Mech, A.; Karbowick, M.; Lis, T. Polyhedron. 2006, 25, 2083–2092.
  9. ^ Bertell, Rosalie. "Gulf War Veterans and Depleted Uranium." May 1999. Available: http://ccnr.org/du_hague.html

[edit] External links