Topic summary
Disulfur dibromide
Disulfur dibromide is the inorganic compound with the formula S2Br2. It is a yellow-brown liquid that fumes in air. It is prepared by direct combination of the elements and purified by vacuum distillation. Higher yields can be obtained from disulfur dichloride and 50% aqueous hydrobromic acid, but the product must be promptly removed from water, lest it hydrolyze. The compound has no particular application, unlike the related sulfur compound disulfur dichloride, although acidic alcoholysis is "an excellent synthesis of alkyl bromides."
The molecular structure is Br−S−S−Br, akin to that of disulfur dichloride (S2Cl2). According to electron diffraction measurements, the angle between the Br−S−S and S−S−Br planes is 84° and the Br−S−S angle is 107°. The S−S distance is 198.0 pm, circa 5.0 pm shorter than for S2Cl2.