Uranyl bromide
| Structural formula | |||||||||
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| No drawing available | |||||||||
| Space group |
P 4 1 2 1 2 (No. 92) |
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| General | |||||||||
| Surname | Uranyl bromide | ||||||||
| other names |
Dibromodioxourane |
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| Molecular formula | UO 2 Br 2 | ||||||||
| Brief description |
light red solid |
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| properties | |||||||||
| Molar mass | 429.836 g mol −1 | ||||||||
| Physical state |
firmly |
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| solubility |
very soluble in water and polar organic solvents |
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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 . | |||||||||
Uranyl bromide , (UO 2 ) Br 2 , is a light red, hygroscopic solid, and is the uranyl salt of hydrobromic acid .
properties
Uranyl bromide is a light red solid that turns yellow in moist air. It is thermally unstable and loses bromine at room temperature. If uranyl bromide is heated to 350 ° C in an inert gas atmosphere, it decomposes within 48 hours. In coordinating solvents, uranyl bromide forms corresponding coordination compounds with the formulas (UO 2 ) Br 2 L (L = acetonitrile ), (UO 2 ) Br 2 2 L (L = acetic anhydride , diethyl ether , N -methylacetanilide ), (UO 2 ) Br 2 · 3 L (L = N , N -dimethylformamide ) and (UO 2 ) Br 2 · 4 L (L = dimethyl sulfoxide ) as well as twofold, threefold and fourfold coordinated complexes with ammonia according to the formula (UO 2 ) Br 2 · x NH 3 (x = 2, 3, 4). Uranyl bromide also forms a stable trihydrate (UO 2 ) Br 2 · 3 H 2 O in the form of dark yellow needles from aqueous HBr solution. Drying over phosphoric acid gives the monohydrate (UO 2 ) Br 2 · H 2 O. The trihydrate is stable in air and loses a molecule of water of crystallization when heated to 60 ° C. In ionic liquids , uranyl bromide forms the corresponding tetrabromo anion [(UO 2 ) Br 4 ] 2− with bromide ions .
presentation
Uranyl bromide can be obtained by reacting anhydrous uranium (IV) bromide with oxygen at a temperature between 150 and 160 ° C.
Electrochemical anodic oxidation of uranium metal in the presence of bromine, dissolved in acetonitrile and in the presence of dry oxygen is also possible.
Health and environmental hazards
Uranyl bromide, like all uranium compounds, is radioactive and poisonous and should therefore be handled with appropriate care and absorption into the body avoided.
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 .
Individual evidence
- ^ Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 782 ( limited preview in Google Book search).
- ↑ a b c d Lester R. Morss, Norman M. Edelstein, Jean Fuger (Eds.): The Chemistry of the Actinide and Transactinide Elements. Springer, Dordrecht 2006, p. 571.
- ↑ 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.
- ^ Sigfred Peterson, Journal of Inorganic and Nuclear Chemistry , Volume 17 , Issues 1-2, 1961 , pp. 135-137.
- ↑ Marie-Olga Sornein, Mickaël Mendes, Céline Cannes, Claire Le Naour, Peter Nockemann, Kristof Van Hecke, Luc Van Meervelt, Jean-Claude Berthet, Christoph Hennig, Polyhedron , 2009 , 28 (7), pp. 1281-1286.
- ↑ N. Kumar, Dennis G. Tuck, Inorganica Chimica Acta , Volume 95 , Issue 4, 1984 , pp. 211-215.