Neptunium (III) bromide
Crystal structure | |||||||
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α-NpBr 3 (left) β-NpBr 3 (right) |
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__ Np 3+ __ __ Br - | |||||||
Crystal system |
α-NpBr 3 : hexagonal |
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Space group |
α-NpBr 3 : P 6 3 / m (No. 176)
β-NpBr 3 : Ccmm (No. 63, position 2) |
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Lattice parameters |
α-NpBr 3 : |
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General | |||||||
Surname | Neptunium (III) bromide | ||||||
other names |
Neptunium tribromide |
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Ratio formula | NpBr 3 | ||||||
Brief description |
green solid |
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External identifiers / databases | |||||||
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properties | |||||||
Molar mass | 476.76 g mol −1 | ||||||
Physical state |
firmly |
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density |
6.62 g cm −3 |
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Hazard and safety information | |||||||
Radioactive |
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Thermodynamic properties | |||||||
ΔH f 0 |
−185 kcal mol −1 |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Neptunium (III) bromide is a chemical compound made up of the elements neptunium and bromine . It has the formula NPBR 3 and belongs to the class of the bromides .
presentation
Neptunium (III) bromide can be produced by reacting neptunium (IV) oxide (NpO 2 ) with aluminum bromide (AlBr 3 ).
properties
Physical Properties
Neptunium (III) bromide is a green solid. It crystallizes in two different forms:
- α-NpBr 3 in the hexagonal crystal system in the space group P 6 3 / m (No. 176) with the lattice parameters a = 791.7 pm and c = 438.2 pm. It is isostructural to uranium (III) chloride .
- β-NpBr 3 in the orthorhombic crystal system ( plutonium (III) bromide type) in the space group Ccmm (No. 63, position 2) with the lattice parameters a = 411 pm , b = 1265 pm and c = 915 pm and four formula units per Unit cell . It is isostructural to the bromides of the actinide elements plutonium to californium .
The hexahydrate, which is also green, has a monoclinic crystal structure with the space group P 2 / n (No. 13, position 2) .
Chemical properties
Heating neptunium (III) bromide with excess bromine at 425 ° C leads to neptunium (IV) bromide (NpBr 4 ).
safety instructions
Classifications according to the CLP regulation are not available because they only include chemical hazard and play a completely subordinate role compared to the hazards based on radioactivity . The latter also only applies if the amount of substance involved is relevant.
Individual evidence
- ↑ a b c d e f C. Keller: The chemistry of Neptunium. In: Fortschr. chem. Forsch. , 1969/70 , 13/1 , p. 69.
- ^ 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 c d e Gmelin's Handbook of Inorganic Chemistry , System No. 71, Transurane, Part C, pp. 148-150.
- ↑ 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 Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1268.
literature
- Zenko Yoshida, Stephen G. Johnson, Takaumi Kimura, John R. Krsul: Neptunium , 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. 699-812 ( doi : 10.1007 / 1-4020-3598-5_6 ).
- C. Keller: The chemistry of neptunium. In: Fortschr. chem. Forsch. , 1969/70 , 13/1 , pp. 1–124 ( doi : 10.1007 / BFb0051170 ).