Arsenic tribromide
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. The compound exists as colourless deliquescent crystals that fume in moist air.
Preparation
Arsenic tribromide is optimally prepared by treating arsenic(III) oxide with hot concentrated hydrobromic acid.It can also be prepared by the direct bromination of arsenic powder. Alternatively, arsenic oxide can be treated with a mixture of elemental sulfur and bromine:
Arsenic tribromide hydrolyzes readily. It is soluble in hydrocarbons.
Bromides of arsenic
is not known, although the corresponding phosphorus compound is well characterized. is the parent for a series of hypervalent anionic bromoarsenates including,, and.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.