Tags: Chemical Compound, Chemical Substance.
Phosphorus pentabromide is a reactive yellow solid of formula PBr5 which has the structure PBr4+ Br− in the solid state but in the vapor phase is completely dissociated to PBr3 and Br2. Rapid cooling of this phase to 15 K leads to formation of the ionic species [PBr4]+[Br3]-. It can be used in organic chemistry to convert carboxylic acids to acyl bromides. It is highly corrosive and should be handled with care.
