SnBr4

Tin tetrabromide, or tin(IV) bromide, is a chemical compound with the formula SnBr4. It represents tin in the +4 oxidation state in a covalent, tetrahalogenated environment. The compound is typically described as a white crystalline solid that is sensitive to moisture.

The structure of SnBr4 features four tin–bromine bonds arranged around a tetrahedral tin center. As a heavier halide analog of tin tetrachloride, SnBr4 behaves as a Lewis acid and forms adducts with donors such as ethers or phosphines. It is generally less volatile than SnCl4 and is reactive toward water, but the exact physical properties, including melting and boiling points, are less well characterized in the literature.

SnBr4 is usually prepared by direct bromination of tin metal at elevated temperature in a dry environment. It can also be formed by halide exchange routes in suitable non-aqueous media. The compound is moisture sensitive and rapidly hydrolyzes in water or humid air, yielding tin oxyhalide species and hydrobromic acid. In organic synthesis, SnBr4 can act as a Lewis acid catalyst or brominating agent, but its use is more limited than tin tetrachloride due to its greater hydrolytic lability and handling challenges.

Safety and handling considerations are important: SnBr4 is corrosive and toxic, and releases acidic vapors such as hydrobromic acid upon hydrolysis. It should be stored under inert atmosphere in tightly sealed containers and kept away from moisture and incompatible materials.

See also: tin tetrachloride (SnCl4) and tin tetraiodide (SnI4).