2220. Chromic Bromide

Nomenclature

CAS number: 10031-25-1
Br3Cr; mol wt 291.71.
Br 82.17%, Cr 17.82%.
CrBr3.

Description and references

Prepd by passing Br2 vapor over Cr powder at 1000°: Hein, Herzog, in Handbook of Preparative Inorganic Chemistry vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) p 1341.

Properties

Black, lustrous, hexagonal crystals; green in transmitted and reddish in reflected light. Sol in cold water only upon addition of chromous salts; sol in boiling water.

Derivative

Hexahydrate.

Properties

At least two isomeric forms exist. Dibromotetraaquochromium bromide dihydrate, [CrBr2(H2O)4]Br.2H2O; green, deliquesc crystals; sol in water, alc. Hexaaquochromium tribromide, [Cr(H2O)6]Br3; violet, deliquesc crystals; sol in water. Insol in alc. Both forms practically insol in ether.

Use

In catalysts for polymerization of olefins.