Carbonyl bromide, decomposition

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 ... 

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. 

FORMYL TRIBROMIDE (75-25-2) CHBrj Noncombustible liquid. Violent reaction with chemically active metals, acetone, calciiun, strong caustics, potassium, potassium hydroxide, sodium hydroxide. Increases die explosive sensitivity of nitromethane. Incompatible with crown polyediers, sodium-potassium alloys. Forms fiiction- and shock-sensitive compounds with hthium. Aqueous solution is a medium-strong acid. Liquid attacks some plastics, rabber, and coatings. Corrosive to most metals in the presence of moisture. Thermal decomposition products include highly toxic carbonyl bromide and hydrogen bromide fumes. On small fires, use dry chemical powder (such as Purple-K-Powder), foam, or CO2 extinguishers. 

The decomposition products of Halon 1301 are dangerous in sufficient concentrations. The chief ones are the acids of the halide components, HF, HBr, and Brj. Fluorine is too reactive to be present in substantial amoimts alone. Small amounts of carbonyl fluoride and carbonyl bromide (COFj and COBrj), respectively, have been found as well. Because of the potential for these toxic materials being present after the intervention of a Halon 1301 system in a fire, fire persormel and others entering the area of a fire should exercisecaution. Where the fire involves substantial amoimts of solid fuel, the use of a positive pressure, air-supplied breathing apparatus is recommended to search the area for injured personnel. 

This cyclization is a reaction developed by Mori, who carried out a series of investigations with tin reagent 33. Fluoride is a much more reactive anion for initiation than any of the other halides, although it often leads to decomposition of the starting materials. In the case of vinylic or aryl halogen compounds the iodides are easier to transform than the bromides, and chlorides are unrcactive. The carbonyl group can be derived from either an aldehyde or a ketone, and even esters are sufficiently electrophilic.22... 

Cobalt Tetra-carbonyl, Co(C0)4 or Co2(CO)g.—This compound may be prepared by passing carbon monoxide at a pressure of 40 atmospheres over reduced cobalt at 150° C. The higher the pressure the more rapid is the formation of the earbonyl.7 It forms as fine, orange-coloured transparent crystals, which are best preserved by hermetically sealing them in a glass tube in an atmosphere of hydrogen or of carbon monoxide. Upon exposure to air decomposition takes place resulting in the formation of a basic cobalt carbonate. With bromine it yields cobalt bromide and carbon monoxide ... 

The 1,5,2,4-dioxazadiazinedione system (35) has been prepared. However, these compounds decompose very readily. Thermal decomposition leads to carbon dioxide loss with the formation of isocyanates and nitrosoalkanes (Equation (1)). The compounds are stable to water, but are attacked by organic soluble nucleophiles, and reagents such as phenylmagnesium bromide, to yield products which arise from attack of the nucleophile at the carbonate carbonyl, followed by fragmentation (Equation (1)). Catalytic reduction of (35) leads to ureas <86JOC3355>. 

The present preparation Illustrates a general and convenient method for a two-step deoxygenation of carbonyl compounds to olefins. Related procedures comprise the basic decomposition of p-toluenesulfonylhydrazones,2 the hydride reduction of enol ethers,3 enol acetates,9 enamines,3 3 the reduction of enol phosphates (and/or enol phosphorodlamidates) by lithium metal in ethylamine (or liquid ammonia),33 the reduction of enol phosphates by titanium metal under aprotic conditions,32 the reduction of thioketals by Raney nickel,33 and the reduction of vinyl sulfides by Raney nickel in the presence of isopropylmagnesium bromide.3 ... 

The iron carbonyl halides are light-sensitive water converts them to the corresponding Fe (11) salt solutions (the chloride and bromide react instantaneously, the iodide only upon heating). The thermal decomposition of iron carbonyl halides is a convenient way to produce fine powders of anhydrous Fe(II) halides. 

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