Arsenic tribromide is an inorganic compound with the formula, it is a bromide of arsenic. Arsenic is a chemical element that has the symbol As and atomic number 33. This pyramidal molecule is the only known binary arsenic bromide. is noteworthy for its very high refractive index of approximately 2.3. It also has a very high diamagnetic susceptibility.[1] The compound exists as colourless deliquescent crystals that fume in moist air.
Arsenic tribromide can be prepared by the direct bromination of arsenic powder. Alternatively, arsenic(III) oxide can be used as the precursor in the presence of elemental sulfur:
Arsenic tribromide is a highly water soluble crystalline arsenic source for uses compatible with bromides and lower (acidic) pH. Most metal bromide compounds are water soluble for uses in water treatment, chemical analysis and in ultra high purity for certain crystal growth applications. Arsenic bromide is generally immediately available in most volumes.[2]
It is soluble in hydrocarbons; carbon tetrachloride; very soluble in ether, benzene, chlorinated hydrocarbons, carbon disulfide, oils, and fats.
is not known, although the corresponding phosphorus compound is well characterized. is the parent for a series of hypervalent anionic bromoarsenates including,, and .[3]
Organoarsenic bromides and are formed efficiently by the copper-catalyzed reaction of methyl bromide with hot arsenic metal. This synthesis is similar to the direct process used for the synthesis of methyl chlorosilanes.
Arsenic tribromide is highly toxic. It is a carcinogen and a teratogen.