Chemistry:Protactinium(IV) bromide

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Protactinium(IV) bromide
Kristallstruktur Uran(IV)-chlorid.png
Names
IUPAC name
Protactinium(IV) tetrabromide
Identifiers
3D model (JSmol)
Properties
PaBr4
Molar mass 550.652
Appearance red crystals
Structure
tetragonal crystal system[1][2],tI20
I41/amd , No. 141
Related compounds
Other anions
Protactinium(IV) fluoride
Protactinium(IV) chloride
Protactinium(IV) iodide
Other cations
Uranium(IV) bromide
Thorium(IV) bromide
Praseodymium(III) bromide
Related compounds
Protactinium(V) bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Protactinium(IV) bromide is an inorganic compound. It is an actinide halide, composed of protactinium and bromine. It is radioactive, and has the chemical formula of PaBr4. It may be due to the brown color of bromine that causes the appearance of protactinium(IV) bromide to be brown crystals. Its crystal structure is tetragonal.[1][2] Protactinium(IV) bromide is sublimed in a vacuum at 400 °C.[1] The protactinium(IV) halide closest in structure to protactinium(IV) bromide is protactinium(IV) chloride.

Preparation

Protactinium(IV) bromide can be prepared by reacting protactinium(V) bromide with hydrogen gas or aluminium:[3]

[math]\displaystyle{ \mathsf{ 3 PaBr_5 + Al \ \xrightarrow{400-450^oC}\ 3 PaBr_4 + AlBr_3 } }[/math]
[math]\displaystyle{ \mathsf{ 2 PaBr_5 + H_2 \ \xrightarrow{800^oC}\ 2 PaBr_4 + 2 HBr } }[/math]

Properties

Protactinium(IV) bromide reacts with antimony trioxide to form protactinium bromate:[4]

[math]\displaystyle{ \mathsf{ 3 PaBr_4 + Sb_2O_3 \ \xrightarrow{150-200^oC}\ 3 PaOBr_2 + 2 SbBr_3 } }[/math]

See also

References

  1. 1.0 1.1 1.2 Tahri, Y; Chermette, H; Elkhatib, N; Krupa, J; Simoni, E (1990). "Electronic structures of thorium and protactinium halide clusters of [ThX8]4− type". Journal of the Less Common Metals 158: 105–116. doi:10.1016/0022-5088(90)90436-N. 
  2. 2.0 2.1 Brown, D.; Petcher, T. J.; Smith, A. J. (1968). "Crystal Structures of some Protactinium Bromides". Nature 217 (5130): 737. doi:10.1038/217737a0. Bibcode1968Natur.217..737B. 
  3. Руководство по неорганическому синтезу: В 6-ти т.. 4. М.: Мир. 1985. 
  4. Morss, Lester R.; Edelstein, Norman M.; Fuger, J. (2010). The chemistry of the actinide and transactinide elements. Volumes 1-6. Dordrecht: Springer. p. 874. ISBN 978-94-007-0211-0. OCLC 682907473.