Neptunium(III) bromide explained

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

Preparation

Neptunium(III) bromide can be prepared by reacting neptunium dioxide and aluminium bromide:^[1]

Properties

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. 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. It has the same structure as the bromides from plutonium to californium.

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

Reactions

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

Notes and References

1. [Georg Brauer]