Thionyl bromide

Thionyl bromide

Names
IUPAC name Thionyl bromide
Other names Sulfur oxy dibromide
Identifiers
CAS Number	507-16-4 N
ChemSpider	61483 Y
Jmol 3D model	Interactive image
PubChem	68176
InChI InChI=1S/Br2OS/c1-4(2)3 Y Key: HFRXJVQOXRXOPP-UHFFFAOYSA-N Y InChI=1/Br2OS/c1-4(2)3 Key: HFRXJVQOXRXOPP-UHFFFAOYAY
SMILES BrS(Br)=O
Properties
Chemical formula	SOBr2
Molar mass	207.87 g/mol
Appearance	colorless liquid
Density	2.688 g/mL, liquid
Melting point	−52 °C (−62 °F; 221 K)
Boiling point	68 °C (154 °F; 341 K) at 40 mmHg
Solubility in water	decomposes
Solubility	reacts in HBr, acetone, and alcohol soluble in benzene, toluene, ether
Structure
Molecular shape	trigonal pyramidal
Vapor pressure	{{{value}}}
Related compounds
Related compounds	SOCl2, SeOCl2; PBr3, Br2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Thionyl bromide is the chemical compound SOBr₂. 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:

SOCl₂ + 2HBr → SOBr₂ + 2HCl

Thionyl bromide is used for some brominations of certain α,β-unsaturated carbonyls, and it also converts alcohols to alkyl bromides. Otherwise it hydrolyzes readily to release sulfur dioxide:

SOBr₂ + H₂O → SO₂ + 2HBr

Safety

SOBr₂ hydrolyzes readily to release dangerous HBr and acts as a lachrymator.