Thionyl bromide 5199120 183989750 2008-01-13T05:47:52Z Rifleman 82 1255637 fix box {{Chembox new | Name = Thionyl bromide | ImageFile = Thionyl-bromide.png <!-- | ImageSize = 120px --> | ImageName = Structure of the thionyl bromide molecule | ImageFile1 = Thionyl-bromide-3D-space-filling.png <!-- | ImageSize1 = 120px --> | ImageName1 = 3D model of a thionyl bromide molecule | IUPACName = Thionyl bromide | OtherNames = Sulfur oxy dibromide | Section1 = {{Chembox Identifiers | SMILES = O=S(Br)Br | CASNo = 507-16-4 | RTECS = }} | Section2 = {{Chembox Properties | Formula = SOBr<sub>2</sub> | MolarMass = 207.87 g/mol | Appearance = colorless liquid | Density = 2.688 g/mL, liquid | Solubility = decomposes violently | MeltingPt = –52 °C | BoilingPt = 68 °C/40 mmHg | Viscosity = }} | Section3 = {{Chembox Structure | MolShape = trigonal pyramidal | Dipole = }} | Section7 = {{Chembox Hazards | ExternalMSDS = | MainHazards = dangerously sensitive to water<br />source of bromine, HBr | FlashPt = nonflammable | RPhrases = 14-20/21-34 | SPhrases = 26-36/37/39-45 }} | Section8 = {{Chembox Other | OtherCpds =[[Thionyl chloride|SOCl<sub>2</sub>]], [[Selenium oxydichloride|SeOCl<sub>2</sub>]]; PBr<sub>3</sub>, Br<sub>2</sub>}} }} '''Thionyl bromide''' is the chemical compound SOBr<sub>2</sub>. It is less stable and less widely used than its chloride analogue, thionyl chloride. It is prepared by the action of [[hydrogen bromide]] on thionyl chloride, a characteristic reaction where a stronger acid is converted to a weaker acid: :SOCl<sub>2</sub> + 2HBr → SOBr<sub>2</sub> + 2HCl Thionyl bromide is used for some brominations of certain α,β-unsaturated carbonyls, and it also converts [[alcohol]]s to alkyl bromides. Otherwise it hydrolyzes readily to release [[sulfur dioxide]]: :SOBr<sub>2</sub> + H<sub>2</sub>O → SO<sub>2</sub> + 2HBr ==Safety== SOBr<sub>2</sub> hydrolyzes readily to release dangerous [[Hydrogen bromide|HBr]]. It also reacts with acetone to give a hazardous lacrymator. ==References== Mundy, B. P. "Thionyl Bromide" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. [[Category:Inorganic sulfur compounds]] [[Category:Bromides]] [[Category:Thionyl compounds]] {{inorganic-compound-stub}} [[ca:Template:Chembox]] [[es:Plantilla:Chembox]] [[fr:Modèle:Chimiebox général]]