Thorium (IV) bromide
General | ||||||||||||||||
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Surname | Thorium (IV) bromide | |||||||||||||||
other names |
Thorium tetrabromide |
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Molecular formula | ThBr 4 | |||||||||||||||
Brief description |
white solid |
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properties | ||||||||||||||||
Molar mass | 551.65 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
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Melting point |
679 ° C |
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solubility |
very soluble in water, ethanol and ethyl acetate |
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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 . |
Thorium (IV) bromide is an inorganic chemical compound of thorium from the group of bromides .
Extraction and presentation
Thorium (IV) bromide can be obtained by reacting thorium (IV) oxide with bromine and carbon at 800 to 900 ° C. In the normal preparation process, a mixture of α- and β-thorium (IV) bromide is usually obtained. Pure α-thorium (IV) bromide is obtained when the mixture is heated to 330-375 ° C for a prolonged period. Pure β-thorium (IV) bromide is produced when the product is heated to 470 ° C and quenched in ice water.
Thorium (IV) bromide can also be obtained by reacting thorium with bromine or thorium (IV) hydroxide with hydrobromic acid, with hydrates being formed in the latter reaction.
properties
Thorium (IV) bromide has a low-temperature form (α-form) and a high-temperature form (β-form). α- and β-thorium (IV) bromide form white, crystalline hygroscopic masses that are very soluble in water, ethanol and ethyl acetate. Thorium (IV) bromide is attacked by fluorine under normal conditions, by chlorine and oxygen when heated. β-Thorium (IV) bromide is metastable at room temperature; it converts into the stable α modification over the course of 10 to 12 weeks. The α-> β transformation takes place at around 420 ° C. α-Thorium (IV) bromide crystallizes in an orthorhombic crystal structure (a = 1361 pm, b = 1205 pm, c = 782.1 pm). β-Thorium (IV) bromide crystallizes in a tetragonal crystal structure with the space group I 4 1 / amd (space group no. 141) and the lattice parameters a = 893.9 pm, c = 769.4 pm. Some hydrates of the compound are known. These decompose to thorium oxide bromide when heated .
Individual evidence
- ↑ a b c d e f g Georg Brauer , with the assistance of Marianne Baudler u. a. (Ed.): Handbook of Preparative Inorganic Chemistry . 3rd, revised edition. tape I . Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , pp. 1136 .
- ^ William M. Haynes: CRC Handbook of Chemistry and Physics, 93rd Edition . CRC Press, 2012, p. 94 ( limited preview in Google Book search).
- ↑ The hazards emanating from radioactivity do not belong to the properties to be classified according to the GHS labeling. With regard to other hazards, this substance has either not yet been classified or a reliable and citable source has not yet been found.
- ^ A b Lester R. Morss, Norman M. Edelstein, J. Fuger (Ed.): The Chemistry of the Actinide and Transactinide Elements (Set Vol. 1-6) . Springer, 2010, ISBN 978-94-007-0211-0 , pp. 81 f . ( limited preview in Google Book search).