Promethium(III) bromide is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

, with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

of PmBr₃. It is radioactive salt. It is a crystal of the

hexagonal crystal system In crystallography, the hexagonal crystal family is one of the six crystal family, crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the tr ...

, with the

space group In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that ...

of P6₃/mc (No. 176).

Preparation

Promethium(III) bromide can be obtained by reacting

hydrogen bromide Hydrogen bromide is the inorganic compound with the formula . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temper ...

and

promethium(III) oxide Promethium(III) oxide is a compound with the formula Pm2O3. It is the most common form of promethium. Crystal structure Promethium oxide exists in three major crystalline forms: *a, b and c are lattice parameters, Z is the number of formula ...

: : Pm₂O₃ + 6 HBr —^500°C→ 2 PmBr₃ + 3 H₂O Promethium(III) bromide hydrate cannot be heated to form its anhydrous form. Instead it decomposes in water to form promethium oxybromide: : PmBr₃ + H₂O(g) → PmOBr + 2 HBr

References

{{Lanthanide halides category:Bromides category:Promethium compounds Lanthanide halides