Английская Википедия:Chromium(III) bromide
Шаблон:Chembox Chromium(III) bromide is an inorganic compound with the chemical formula Шаблон:Chem2. It is a dark colored solid that appears green in transmitted light but red with reflected light. It is used as a precursor to catalysts for the oligomerization of ethylene.
Synthesis
The compound is prepared in a tube furnace by the reaction of bromine vapor and chromium powder at 1000 °C. It is purified by extracting with absolute diethyl ether to remove any [[Chromium(II) bromide|Шаблон:Chem2]], and is subsequently washed with absolute diethyl ether and absolute ethanol.[1]
Analogous to the behavior of related chromium(III) halides, the tribromide dissolves in water to give Шаблон:Chem2 only upon the addition of catalytic amounts of a reducing agent, which generates Шаблон:Chem2.[1] The reducing agent generates chromous bromide on the surface of the solid, which dissolves and re-oxidizes to Cr(III).Шаблон:Cn
Reactions
Chromium(III) bromide is reduced by hydrogen gas at 350-400 °C to give chromium(II) bromide:[1]
References
Шаблон:Reflist Шаблон:Chromium compounds Шаблон:Bromine compounds
