Carbonyl bromide

Carbonyl bromide

Structural formula of carbonyl bromide Ball-and-stick model of carbonyl bromide
Names
Other names Bromophosgene, carbonic dibromide, carbonyl dibromide
Identifiers
CAS Number	593-95-3 Y=
ChemSpider	71389 Y
Jmol 3D model	Interactive image
PubChem	79057
InChI InChI=1S/CBr2O/c2-1(3)4 Y Key: MOIPGXQKZSZOQX-UHFFFAOYSA-N Y InChI=1/CBr2O/c2-1(3)4 Key: MOIPGXQKZSZOQX-UHFFFAOYAM
SMILES BrC(Br)=O
Properties
Chemical formula	COBr2
Molar mass	187.818 g/mol
Appearance	colorless liquid
Density	2.52 g/ml at 15°C
Boiling point	64.5 °C (148.1 °F; 337.6 K) decomposes
Solubility in water	reacts
Thermochemistry
Specific heat capacity (C)	61.8 J·mol−1·K−1 (gas)
Std molar entropy (So298)	309.1 J·mol−1·K−1 (gas)
Std enthalpy of formation (ΔfHo298)	-127.2 or -145.2 kJ·mol−1 (liquid) -96.2 or -114 kJ·mol−1 (gas)
Vapor pressure	{{{value}}}
Related compounds
Related compounds	Carbonyl fluoride Phosgene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)
Infobox references

Carbonyl bromide, also known as bromophosgene by analogy to phosgene, is an organic chemical compound. It is a decomposition product of halon compounds used in fire extinguishers.

Reactions

Carbonyl bromide is formed when carbon tetrabromide is melted and concentrated sulfuric acid is added.

In contrast to phosgene, carbonyl bromide cannot be produced efficiently from carbon monoxide and bromine. A complete conversion is not possible due to thermodynamic reasons. Additionally, the reaction

CO + Br₂ <-> COBr₂

processes slowly at room temperature. Increasing temperature, in order to increase the reaction rate, results in a further shift of the chemical equilibrium towards the educts (since Δ_RH < 0 and Δ_RS < 0).

On the other hand, carbonyl bromide slowly decomposes to carbon monoxide and elemental bromine even at low temperatures. It is also sensitive to hydrolysis.