Protactinium(V) fluoride
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3D model (JSmol)
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PubChem CID
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| Properties | |
| PaF5 | |
| Molar mass | 326.02790 g·mol−1 |
| Appearance | white solid[1] |
| Soluble in water and hydrofluoric acid[1] | |
| Related compounds | |
Other anions
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Other cations
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Uranium(V) fluoride |
Related compounds
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Protactinium(IV) fluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Protactinium(V) fluoride is a fluoride of protactinium with the chemical formula PaF5.
Preparation
[edit]Protactinium(V) fluoride can be obtained by reacting protactinium(V) oxide with bromine trifluoride or bromine pentafluoride at 600 °C:[1]
- 6 Pa2O5 + 20 BrF3 → 12 PaF5 + 10 Br2 + 15 O2
- 6 Pa2O5 + 12 BrF5 → 12 PaF5 + 6 Br2 + 15 O2
It can also be obtained by reacting protactinium(V) chloride or protactinium(IV) fluoride with fluorine gas at 700 °C:[1]
- 2 PaF4 + F2 → 2 PaF5
The hydrate form of protactinium(V) fluoride can be formed by the reaction of protactinium(V) oxide and hydrofluoric acid in an aqueous solution:[1]
- Pa2O5 + 10 HF → 2 PaF5·2H2O + 6 H2O
It can also be decomposed from fluorine-containing protactinium complexes.[2]
Properties
[edit]Protactinium(V) fluoride is a white, volatile, extremely hygroscopic solid that is partially soluble in water and soluble in hydrofluoric acid. It has a tetragonal crystal structure of the β-uranium pentafluoride type with the space group I42d (space group no. 122) with the lattice parameters a = 1153 pm, c = 510 pm. Quartz and Pyrex are attacked by the compound at higher temperatures. As a dihydrate, it is a colourless, hygroscopic, crystalline solid that is waxy in nature. It is soluble in water and hydrofluoric acid.[1] It reacts with phosphorus trifluoride to form protactinium(IV) fluoride.[3] The dihydrate cannot be converted into the anhydrous form in air, hydrogen fluoride or fluorine at low temperatures. Instead, diprotactinium(V) oxide octafluoride (Pa2OF8) is formed. At higher temperatures around 325 °C, a mixture of the diprotactinium(V) oxide octafluoride and protactinium(V) fluoride is formed.[2]
References
[edit]- ^ a b c d e f Brauer, Georg (1975). Handbuch der Präparativen Anorganischen Chemie. F. Enke. p. 1170. ISBN 3432023286.
- ^ a b G. Meyer; Lester R. Morss (1991). Synthesis of Lanthanide and Actinide Compounds (in German). Springer. p. 77. ISBN 9780792310181.
- ^ Lester R. Morss; Norman M. Edelstein; J. Fuger, eds. (2010). The Chemistry of the Actinide and Transactinide Elements (in German). Vol. 1. Springer. p. 198. ISBN 978-94-0070211-0.