Protactinium(IV) bromide

Protactinium(IV) bromide
Names
	IUPAC name Protactinium(IV) tetrabromide
Identifiers
CAS Number	13867-42-0 ;
3D model (JSmol)	Interactive image;
	SMILES [Pa](Br)(Br)(Br)Br;
Properties
Chemical formula	PaBr4
Molar mass	550.652
Appearance	红色晶體
Structure
Crystal structure	四方晶系，tI20
Space group	I41/amd , No. 141
	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 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 protatcinium(V) bromide with hydrogen gas or aluminium:^[3]

{\mathsf {3PaBr_{5}+Al\ {\xrightarrow {400-450^{o}C}}\ 3PaBr_{4}+AlBr_{3}}}

{\mathsf {2PaBr_{5}+H_{2}\ {\xrightarrow {800^{o}C}}\ 2PaBr_{4}+2HBr}}

Properties

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

{\mathsf {3PaBr_{4}+Sb_{2}O_{3}\ {\xrightarrow {150-200^{o}C}}\ 3PaOBr_{2}+2SbBr_{3}}}

References

^ ^a ^b ^c 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. doi:10.1016/0022-5088(90)90436-N.
^ ^a ^b Brown, D.; Petcher, T. J.; Smith, A. J. (1968). "Crystal Structures of some Protactinium Bromides". Nature. 217 (5130): 737. doi:10.1038/217737a0.
^ Руководство по неорганическому синтезу: В 6-ти т. Vol. 4. М.: Мир. 1985. {{cite book}}: Unknown parameter |agency= ignored (help)
^ 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.

[pabr4-1] 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. doi:10.1016/0022-5088(90)90436-N.

[pabr5b-2] Brown, D.; Petcher, T. J.; Smith, A. J. (1968). "Crystal Structures of some Protactinium Bromides". Nature. 217 (5130): 737. doi:10.1038/217737a0.

[Брауэр-3] Руководство по неорганическому синтезу: В 6-ти т. Vol. 4. М.: Мир. 1985. {{cite book}}: Unknown parameter |agency= ignored (help)

[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.

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