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Neptunium tetrabromide
Names
Other names
neptunium(IV) bromide
Identifiers
Properties
Br4Np
Molar mass 557 g·mol−1
Appearance red-brown crystals
Density 5.5 g/cm3
Melting point 464 °C (867 °F; 737 K)
Related compounds
Related compounds
Uranium tetrabromide, Thorium tetrabromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Neptunium tetrabromide is a binary inorganic compound of neptunium metal and bromine with the chemical formula NpBr4.[1][2][3][4]

Synthesis[edit]

The compound can be prepared from the reaction of bromine with metallic neptunium:

Np + 2Br2 → NpBr4

Also, a reaction of aluminum bromide with neptunium(IV) oxide:[5][6]

3NpO2 + 4AlBr3 → 3NpBr4 + 2Al2O3

Physical properties[edit]

Neptunium tetrabromide forms red-brown hygroscopic crystals of monoclinic crystal system, spatial group P 2/c,[7][8] cell parameters a = 1.089 nm, b = 0.874 nm, c = 0.705 nm, β = 95.19°, Z = 4.[9]

NpBr4 is easily purified by sublimation in a vacuum.[10]

Chemical properties[edit]

Decomposes under strong heating to form neptunium tribromide:

2NpBr4 → 2NpBr3 + Br2

With careful oxidation with antimony(III) oxide, the compound forms neptunium oxidibromide:

NpBr4 + Sb2O3 → NpOBr2 + 2SbOBr

References[edit]

  1. ^ "WebElements Periodic Table » Neptunium » neptunium tetrabromide". webelements.com. Retrieved 2 April 2024.
  2. ^ Stevens, J. L.; Jones, E. R.; Karraker, D. G. (15 February 1976). "Mössbauer spectra and magnetic susceptibility of neptunium tetrabromide". The Journal of Chemical Physics. 64 (4): 1492–1494. doi:10.1063/1.432366. Retrieved 2 April 2024.
  3. ^ Brown, D.; Hill, J.; Rickard, C. E. F. (1 January 1970). "Preparation of actinide bromides and bromo-complexes by use of liquid boron tribromide or liquid bromine". Journal of the Chemical Society A: Inorganic, Physical, Theoretical (0): 476–480. doi:10.1039/J19700000476. ISSN 0022-4944. Retrieved 2 April 2024.
  4. ^ Yaws, Carl L. (6 January 2015). The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals: Physical Properties for More Than 54,000 Organic and Inorganic Chemical Compounds, Coverage for C1 to C100 Organics and Ac to Zr Inorganics. Gulf Professional Publishing. p. 740. ISBN 978-0-12-801146-1. Retrieved 2 April 2024.
  5. ^ Fried, S. (1947). The Basic Dry Chemistry of Neptunium. Atomic Energy Commission. p. 10. Retrieved 2 April 2024.
  6. ^ Abstracts of Declassified Documents. Technical Information Division, Oak Ridge Directed Operations. 1947. p. 740. Retrieved 2 April 2024.
  7. ^ Morss, L. R.; Edelstein, Norman M.; Fuger, Jean (21 October 2010). The Chemistry of the Actinide and Transactinide Elements (Set Vol.1-6): Volumes 1-6. Springer Science & Business Media. p. 2416. ISBN 978-94-007-0211-0. Retrieved 2 April 2024.
  8. ^ Kirk-Othmer Concise Encyclopedia of Chemical Technology, 2 Volume Set. John Wiley & Sons. 16 July 2007. p. 47. ISBN 978-0-470-04748-4. Retrieved 2 April 2024.
  9. ^ The Chemical Thermodynamics of Actinide Elements and Compounds: The actinide halides. International Atomic Energy Agency. 1983. p. 162. Retrieved 2 April 2024.
  10. ^ Satya, Prakash (2013). Advanced Chemistry of Rare Elements. S. Chand Publishing. p. 684. ISBN 978-81-219-4254-6. Retrieved 2 April 2024.

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