Carbonyl bromide

Carbonyl bromide^[1]
Names
	Preferred IUPAC name Carbonyl dibromide
	Other names Bromophosgene, carbonic dibromide
Identifiers
CAS Number	593-95-3 ;
3D model (JSmol)	Interactive image;
ChemSpider	71389 ;
PubChem CID	79057;
UNII	MNU12QTS1I ;
CompTox Dashboard (EPA)	DTXSID20208041 ;
	InChI InChI=1S/CBr2O/c2-1(3)4 Key: MOIPGXQKZSZOQX-UHFFFAOYSA-N ; 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
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 (ΔfH⦵298)	-127.2 or -145.2 kJ·mol−1 (liquid) ; -96.2 or -114 kJ·mol−1 (gas)
Hazards
NFPA 704 (fire diamond)	4 0 1
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).
	(what is ?)
	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.^[2]

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).^[3]

On the other hand, carbonyl bromide slowly decomposes to carbon monoxide and elemental bromine even at low temperatures.^[4] It is also sensitive to hydrolysis, breaking down into Hydrogen bromide and Carbon dioxide.

References[]

^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 3–96, 4–50, 5–26, ISBN 0-8493-0594-2
^ US Occupational Safety and Health Administration (May 1996). "Common Fire Extinguishing Agents". Archived from the original on 2009-09-12. Retrieved 2009-11-21.
^ T.A. Ryan; E.A. Seddon; K.R. Seddon; C. Ryan (24 May 1996). Phosgene: And Related Carbonyl Halides. pp. 669–671. ISBN 9780080538808. Retrieved April 11, 2015.
^ Katrizsky, Alan R.; Meth-Cohn, Otto; Wees, Charles W. (1995), Organic Functional Group Transformations, 6, Elsevier, pp. 417–8, ISBN 978-0-08-042704-1, retrieved 2009-11-23

[hand-1] Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 3–96, 4–50, 5–26, ISBN 0-8493-0594-2

[2] US Occupational Safety and Health Administration (May 1996). "Common Fire Extinguishing Agents". Archived from the original on 2009-09-12. Retrieved 2009-11-21.

[3] T.A. Ryan; E.A. Seddon; K.R. Seddon; C. Ryan (24 May 1996). Phosgene: And Related Carbonyl Halides. pp. 669–671. ISBN 9780080538808. Retrieved April 11, 2015.

[org-4] Katrizsky, Alan R.; Meth-Cohn, Otto; Wees, Charles W. (1995), Organic Functional Group Transformations, 6, Elsevier, pp. 417–8, ISBN 978-0-08-042704-1, retrieved 2009-11-23

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