This process is analogous to the chlorination of methane: Halogen exchange of carbon tetrachloride with aluminium bromide gives higher yields with aluminium chloride as the byproduct:[4] Tetrabromomethane has two polymorphs: crystalline II or β below 46.9 °C (320.0 K) and crystalline I or α above 46.9 °C.
Roughly speaking, the CBr4 are situated on the corners of the cubic unit cell as well as on the centers of its faces in an fcc arrangement.
It was thought in the past that the molecules could rotate more or less freely (a 'rotor phase'), so that on a time average they would look like spheres.
Moreover, they cannot take these orientations entirely independently from each other because in some cases the bromine atoms of neighboring molecules would point at each other leading to impossibly short distances.
[6] It is used as a solvent for greases, waxes, and oils, in plastic and rubber industry for blowing and vulcanization, further for polymerization, as a sedative and as an intermediate in manufacturing agrochemicals.