Carbonyl bromide

Last updated
Carbonyl bromide [1]
Structural formula of carbonyl bromide Bromphosgen.svg
Structural formula of carbonyl bromide
Ball-and-stick model of carbonyl bromide Carbonyl-bromide-3D-balls.png
Ball-and-stick model of carbonyl bromide
Names
Preferred IUPAC name
Carbonyl dibromide
Other names
Bromophosgene, carbonic dibromide
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
UNII
  • InChI=1S/CBr2O/c2-1(3)4 Yes check.svgY
    Key: MOIPGXQKZSZOQX-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/CBr2O/c2-1(3)4
    Key: MOIPGXQKZSZOQX-UHFFFAOYAM
  • BrC(Br)=O
Properties
COBr2
Molar mass 187.818 g·mol−1
Appearancecolorless liquid
Density 2.52 g/mL at 15 °C
Boiling point 64.5 °C (148.1 °F; 337.6 K) decomposes
reacts
Thermochemistry
61.8 J/(mol·K) (gas)
Std molar
entropy
(S298)
309.1 J/(mol·K) (gas)
−127.2 or −145.2 kJ/mol (liquid)
−96.2 or −114 kJ/mol (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).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Carbonyl bromide, also known as bromophosgene, is an organic chemical compound with the chemical formula COBr2. It is a colorless liquid. It is a bromine analogue of phosgene. It is a carbon oxohalide. Carbonyl bromide is a decomposition product of halon compounds used in fire extinguishers. [2]

Synthesis and reactions

Carbonyl bromide is formed by the oxidation carbon tetrabromide with sulfuric acid:

CBr4 + H2SO4 → COBr2 + SO2 + Br2 + H2O

In contrast to phosgene, carbonyl bromide cannot be produced efficiently by halogenation of carbon monoxide. The bromination of carbon monoxide follows this equation:

CO + Br2 ⇌ COBr2

But the process is slow 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 ΔRH < 0 and ΔRS < 0). [3] [4] [ clarification needed ]

Carbonyl bromide slowly decomposes to carbon monoxide and elemental bromine even at low temperatures. [5] It is also sensitive to hydrolysis, breaking down into hydrogen bromide, water and carbon dioxide.

Related Research Articles

<span class="mw-page-title-main">Bromine</span> Chemical element, symbol Br and atomic number 35

Bromine is a chemical element with the symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig and Antoine Jérôme Balard, its name was derived from the Ancient Greek βρῶμος (bromos) meaning "stench", referring to its sharp and pungent smell.

<span class="mw-page-title-main">Carbon monoxide</span> Colourless, odourless, tasteless and toxic gas

Carbon monoxide is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simplest carbon oxide. In coordination complexes, the carbon monoxide ligand is called carbonyl. It is a key ingredient in many processes in industrial chemistry.

<span class="mw-page-title-main">Phosgene</span> Toxic gaseous compound (COCl2)

Phosgene is an organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. It can be thought of chemically as the double acyl chloride analog of carbonic acid, or strucurally as formaldehyde with the hydrogen atoms replaced by chlorine atoms. Phosgene is a valued and important industrial building block, especially for the production of precursors of polyurethanes and polycarbonate plastics.

In organic chemistry, the Swern oxidation, named after Daniel Swern, is a chemical reaction whereby a primary or secondary alcohol is oxidized to an aldehyde or ketone using oxalyl chloride, dimethyl sulfoxide (DMSO) and an organic base, such as triethylamine. It is one of the many oxidation reactions commonly referred to as 'activated DMSO' oxidations. The reaction is known for its mild character and wide tolerance of functional groups.

<span class="mw-page-title-main">Nickel tetracarbonyl</span> Chemical compound

Nickel carbonyl (IUPAC name: tetracarbonylnickel) is a nickel(0) organometallic compound with the formula Ni(CO)4. This colorless liquid is the principal carbonyl of nickel. It is an intermediate in the Mond process for producing very high-purity nickel and a reagent in organometallic chemistry, although the Mond Process has fallen out of common usage due to the health hazards in working with the compound. Nickel carbonyl is one of the most dangerous substances yet encountered in nickel chemistry due to its very high toxicity, compounded with high volatility and rapid skin absorption.

Phosphorus trifluoride (formula PF3), is a colorless and odorless gas. It is highly toxic and reacts slowly with water. Its main use is as a ligand in metal complexes. As a ligand, it parallels carbon monoxide in metal carbonyls, and indeed its toxicity is due to its binding with the iron in blood hemoglobin in a similar way to carbon monoxide.

<span class="mw-page-title-main">Organoboron chemistry</span> Study of compounds containing a boron-carbon bond

Organoboron chemistry or organoborane chemistry is the chemistry of organoboron compounds or organoboranes, which are chemical compounds of boron and carbon that are organic derivatives of borane (BH3), for example trialkyl boranes..

<span class="mw-page-title-main">Gold(III) chloride</span> Chemical compound

Gold(III) chloride, traditionally called auric chloride, is an inorganic compound of gold and chlorine with the molecular formula Au2Cl6. The "III" in the name indicates that the gold has an oxidation state of +3, typical for many gold compounds. It has two forms, the monohydrate (AuCl3·H2O) and the anhydrous form, which are both hygroscopic and light-sensitive solids. This compound is a dimer of AuCl3. This compound has a few uses, such as an oxidizing agent and for catalyzing various organic reactions.

<span class="mw-page-title-main">Aluminium bromide</span> Chemical compound

Aluminium bromide is any chemical compound with the empirical formula AlBrx. Aluminium tribromide is the most common form of aluminium bromide. It is a colorless, sublimable hygroscopic solid; hence old samples tend to be hydrated, mostly as aluminium tribromide hexahydrate (AlBr3·6H2O).

<span class="mw-page-title-main">Tantalum(V) bromide</span> Chemical compound

Tantalum(V) bromide is the inorganic compound with the formula Ta2Br10. Its name comes from the compound's empirical formula, TaBr5. It is a diamagnetic, orange solid that hydrolyses readily. The compound adopts an edge-shared bioctahedral structure, which means that two TaBr5 units are joined by a pair of bromide bridges. There is no bond between the Ta centres. Niobium(V) chloride, niobium(V) bromide, niobium(V) iodide, tantalum(V) chloride, and tantalum(V) iodide all share this structural motif.

Carbonyl fluoride is a chemical compound with the formula COF2. It is a carbon oxohalide. This gas, like its analog phosgene, is colourless and highly toxic. The molecule is planar with C2v symmetry, bond lengths of 1.174 Å (C=O) and 1.312 Å (C–F), and an F–C–F bond angle of 108.0°.

Bromine compounds are compounds containing the element bromine (Br). These compounds usually form the -1, +1, +3 and +5 oxidation states. Bromine is intermediate in reactivity between chlorine and iodine, and is one of the most reactive elements. Bond energies to bromine tend to be lower than those to chlorine but higher than those to iodine, and bromine is a weaker oxidising agent than chlorine but a stronger one than iodine. This can be seen from the standard electrode potentials of the X2/X couples (F, +2.866 V; Cl, +1.395 V; Br, +1.087 V; I, +0.615 V; At, approximately +0.3 V). Bromination often leads to higher oxidation states than iodination but lower or equal oxidation states to chlorination. Bromine tends to react with compounds including M–M, M–H, or M–C bonds to form M–Br bonds.

Iodine can form compounds using multiple oxidation states. Iodine is quite reactive, but it is much less reactive than the other halogens. For example, while chlorine gas will halogenate carbon monoxide, nitric oxide, and sulfur dioxide, iodine will not do so. Furthermore, iodination of metals tends to result in lower oxidation states than chlorination or bromination; for example, rhenium metal reacts with chlorine to form rhenium hexachloride, but with bromine it forms only rhenium pentabromide and iodine can achieve only rhenium tetraiodide. By the same token, however, since iodine has the lowest ionisation energy among the halogens and is the most easily oxidised of them, it has a more significant cationic chemistry and its higher oxidation states are rather more stable than those of bromine and chlorine, for example in iodine heptafluoride.

<span class="mw-page-title-main">Indium(I) bromide</span> Chemical compound

Indium(I) bromide is a chemical compound of indium and bromine. It is a red crystalline compound that is isostructural with β-TlI and has a distorted rock salt structure. Indium(I) bromide is generally made from the elements, heating indium metal with InBr3. It has been used in the sulfur lamp. In organic chemistry, it has been found to promote the coupling of α, α-dichloroketones to 1-aryl-butane-1,4-diones. Oxidative addition reactions with for example alkyl halides to give alkyl indium halides and with NiBr complexes to give Ni-In bonds are known. It is unstable in water decomposing into indium metal and indium tribromide. When indium dibromide is dissolved in water, InBr is produced as a, presumably, insoluble red precipitate, that then rapidly decomposes.

Organobromine chemistry is the study of the synthesis and properties of organobromine compounds, also called organobromides, which are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane.

<span class="mw-page-title-main">Diphenyl carbonate</span> Chemical compound

Diphenyl carbonate is the organic compound with the formula (C6H5O)2CO. It is classified as an acyclic carbonate ester. It is a colorless solid. It is both a monomer in combination with bisphenol A in the production of polycarbonate polymers and a product of the decomposition of polycarbonates.

<span class="mw-page-title-main">Dioxane tetraketone</span> Chemical compound

Dioxane tetraketone (or 1,4-dioxane-2,3,5,6-tetrone) is an organic compound with the formula C4O6. It is an oxide of carbon (an oxocarbon), which can be viewed as the fourfold ketone of dioxane. It can also be viewed as the cyclic dimer of oxiranedione (C2O3), the hypothetical anhydride of oxalic acid.

<span class="mw-page-title-main">Dibromine monoxide</span> Chemical compound

Dibromine monoxide is the chemical compound composed of bromine and oxygen with the formula Br2O. It is a dark brown solid which is stable below −40 °C and is used in bromination reactions. It is similar to dichlorine monoxide, the monoxide of its halogen neighbor one period higher on the periodic table. The molecule is bent, with C2v molecular symmetry. The Br−O bond length is 1.85 Å and the Br−O−Br bond angle is 112°, similar to dichlorine monoxide.

Rhenium compounds are compounds formed by the transition metal rhenium (Re). Rhenium can form in many oxidation states, and compounds are known for every oxidation state from -3 to +7 except -2, although the oxidation states +7, +6, +4, and +2 are the most common. Rhenium is most available commercially as salts of perrhenate, including sodium and ammonium perrhenates. These are white, water-soluble compounds. Tetrathioperrhenate anion [ReS4] is possible.

<span class="mw-page-title-main">Tungsten hexabromide</span> Chemical compound

Tungsten hexabromide, also known as tungsten(VI) bromide, is a chemical compound of tungsten and bromine with the formula WBr6. It is an air-sensitive dark grey powder that decomposes above 200 °C to tungsten(V) bromide and bromine.

References

  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.
  4. Parkington, Michael J.; Ryan, T. Anthony; Seddon, Kenneth R. (1997). "Carbonyl dibromide: A novel reagent for the synthesis of metal bromides and bromide oxides". Journal of the Chemical Society, Dalton Transactions (2): 257–262. doi:10.1039/A603977D.
  5. Katrizsky, Alan R.; Meth-Cohn, Otto; Wees, Charles W. (1995), Organic Functional Group Transformations, vol. 6, Elsevier, pp. 417–8, ISBN   978-0-08-042704-1 , retrieved 2009-11-23