Carbonyl bromides

Lenher and Schumacher135 first studied the kinetics of the thermal dissociation of COBr2 in 1928. They showed that the reaction 

---

Bromine oxidizes carbon and reacts with carbon monoxide to form carbonyl bromide [593-95-3]. 

Carbonyl bromide/595-95-iy M 187.8, b 64.5°/760mm. Purified by distn from Hg and from powdered Sb to remove free bromine, then vacuum distd to remove volatile SO2 (the major impurity) [Carpenter et al. y Chem Soc. Faraday Trans 2 384 1977]. TOXIC... 

Carbon yields, 72 274 Carbonylation, 73 654-656 ionic liquids in, 26 882-885 methanol, 76 315 of methyl acetylene, 7 6 245 reaction, 70 506-507 Carbonyl bromide, 4 300 Carbonyl clusters, high nuclearity, 76 64-66... 

Begin by considering how an equilibrium system adjusts to a change in the concentration of any substance. At equilibrium, the concentrations of all substances are fixed, and their ratio yields the equilibrium constant. Le Chateliers principle tells you that changing the concentration of a substance causes the system to adjust to minimize the change in that substance. The decomposition of carbonyl bromide provides an illustration ... 

Reaction with phosgene yields carbonyl bromide and aluminum chlorobromide ... 

Carbonyl bromide [593-95-3] M 187.8. Purified by distn from Hg and from powdered Sb to remove free... 

Alkenes, alkynes, and arenes, e.g., ethylene, acetylene and benzene, respectively, react (1) with bromine by addition, e.g., ethylene dibromide C HiBri (1.2). acetylene tetrabromide C2H .Br4 1,1,2,2. hexabromocyclo-hexane QHgBr also carbon monoxide yields carbonyl bromide COBr2i (2) with hypobromous add by addition. e.g., olefins form, for example,... 

A stable polynuclear paramagnetic 7r-cyclopentadienyliron carbonyl bromide [CpFe(CO)]4+Br3 is reported to be formed by oxidation of the tetrameric carbonyl [CpFe(CO)]4 (160). 

The tendency to form the halocarbonyls as a frmction of the halide decreases in the seqnence Cl > Br > I. The carbonyl bromides of palladium(Il), Pd2Br4(CO)2, and gold, AnBr(CO), tend to decarbonylate in the solid state even under CO at atmospheric pressure, and the corresponding carbonyl iodides are unknown. 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by ingestion, inhalation, skin contact, and intraperitoneal routes. See also HYDROBROMIC ACID and ACETIC ACID. Violent reaction on contact with water, steam, methanol, or ethanol produces toxic and reactive HBr. When heated to decomposition it emits highly corrosive and toxic fumes of carbonyl bromide and bromine. To fight fire, use dry chemical, CO2. 

Questionable carcinogen with experimental neoplastigenic data. Mutation data reported. When heated it emits highly toxic fumes of carbonyl bromide and Br . See also ACETYLENE COMPOUNDS and BROMIDES. 

Analogues of phosgene, such as carbonyl bromide have been studied at various times, 1 but experiments on the chemical and particularly toxicological properties have only been carried out in the last few years. ... 

Carbonyl bromide, because of its boiling point (64° C.) and its comparative stability to the action of water would be preferred as a war gas to phosgene were it not for its lower stability to light and its lesser toxicity. 

Oxalyl bromide, (COBr), has been obtained by the action of hydrobromic acid on oxalyl chloride. Heat decomposes it with production of carbon monoxide and carbonyl bromide. It reacts easily with water forming carbon monoxide, carbon dioxide and hydrobromic acid. 

Carbonyl bromide, or bromophosgene, was prepared for the first time by Emmerling by the oxidation of bromoform with potassium dichromate and sulphuric acid. Later it was also obtained by heating boron bromide to 150° C. with phosgene, but by this method a mixture with other compounds is obtained ... 

The most suitable method for the preparation of carbonyl bromide consists in treating carbon tetrabromide with sulphuric... 

Carbonyl bromide easily decomposes under the influence of light and heat, liberating bromine, according to the equation COBr2 = CO 4- Br2. 

The vapour of carbonyl bromide attacks rubber, rendering it hard and brittle. 

---