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Neptunium(III) bromide

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Neptunium(III) bromide
Identifiers
3D model (JSmol)
  • InChI=1S/3BrH.Np/h3*1H;/q;;;+3/p-3
    Key: HVGILCLFCSGPEI-UHFFFAOYSA-K
  • [Np+3].[Br-].[Br-].[Br-]
Properties
Br3Np
Molar mass 477 g·mol−1
Appearance green solid[1]
Density 6.62 g·cm−3[2]
Structure
α-NpBr3: hexagonal

β-NpBr3: orthorhombic

α-NpBr3: P63/m (No. 176)

β-NpBr3: Ccmm (No. 63)

a = 791.7 pm (α), 411 pm (β), b = 791.7 pm (α), 1265 pm (β), c = 438.2 pm (α), 915 pm (β)
Related compounds
Other anions
neptunium(III) fluoride
neptunium(III) chloride
neptunium(III) iodide
Other cations
uranium(III) bromide
plutonium(III) bromide
Related compounds
neptunium(IV) bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Neptunium(III) bromide is a bromide of neptunium, with the chemical formula of NpBr3.

Preparation

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Neptunium(III) bromide can be prepared by reacting neptunium dioxide and aluminium bromide:[3]

6 NpO2 + 8 AlBr3 → 6 NpBr3 + 4 Al2O3 + 3 Br2

Properties

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Neptunium(III) bromide is a green solid. It can crystallize in two crystal systems:

  • α-NpBr3 is hexagonal with lattice parameters a = 791.7 pm and c = 438.2 pm.[2] It has the same structure as uranium trichloride.
  • β-NpBr3 is orthorhombic with lattice parameters a = 411 pm, b = 1265 pm and c = 915 pm.[2] It has the same structure as the bromides from plutonium to californium.

Neptunium(III) bromide also has a green hexahydrate, which is monoclinic.[3]

Reactions

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At 425 °C, neptunium(III) bromide bromide can be further brominated by bromine to form neptunium(IV) bromide.[2]

2 NpBr3 + Br2 → 2 NpBr4

References

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  1. ^ Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, p. 1969, ISBN 0-12-352651-5
  2. ^ a b c d Gmelins Handbuch der anorganischen Chemie, System No. 71, Transurane, Teil C, S. 148–150.
  3. ^ a b Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3, S. 1268.

External reading

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