Plutonium(III) bromide is an

inorganic 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''. Inor ...

salt of

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

and

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

with the formula PuBr₃. This radioactive green solid has few uses, however its

crystal structure In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...

is often used as a structural archetype in

crystallography Crystallography is the branch of science devoted to the study of molecular and crystalline structure and properties. The word ''crystallography'' is derived from the Ancient Greek word (; "clear ice, rock-crystal"), and (; "to write"). In J ...

Crystal structure

The PuBr₃ crystal structure was first published in 1948 by

William Houlder Zachariasen William Houlder Zachariasen (5 February 1906 – 24 December 1979), more often known as W. H. Zachariasen, was a Norwegian-American physicist, specializing in X-ray crystallography and famous for his work on the structure of glass. Background ...

. The compound forms orthorhombic crystals, a type of square antiprism, within which the Pu atoms adopt an 8-coordinate

bicapped trigonal prismatic In chemistry, the bicapped trigonal prismatic molecular geometry describes the shape of compounds where eight atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a biaugmented triangular prism. This sh ...

arrangement. Its

Pearson symbol The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure. It was originated by William Burton Pearson and is used extensively in Pearson's handbook of crystallographic data for intermetallic p ...

is oS16 with the corresponding space group No. 63 (in International Union of Crystallography classification) or Cmcm (in

Hermann–Mauguin notation In geometry, Hermann–Mauguin notation is used to represent the symmetry elements in point groups, plane groups and space groups. It is named after the German crystallographer Carl Hermann (who introduced it in 1928) and the French mineralogist ...

). The majority of trivalent chloride and bromide salts of lanthanide and actinides crystallise in the PuBr₃ structure.

References

Plutonium(III) compounds Actinide halides Crystal structure types {{inorganic-compound-stub