Bromine oxide, decomposition

Iodine oxides and bromine oxides are solid compounds which are beyond the scope of this article and will therefore not be discussed in any detail. Clyne and Coxon410 have found that BrO decays in a similar manner to CIO, with the second order rate coefficient of the order of 2x 108 1.mole-1.sec-1. In view of the important role of CIO in the decomposition of chlorine oxides, it is conceivable that BrO may play a similar role in the decomposition of bromine oxides. However, no kinetic information on the decomposition of bromine oxides in the gas phase appears to be available at the present time. 

The bromine-photosensitized decomposition of O3 was studied at 20° C by Spinks , who used radiation at 5460 and 3650 A. The yield of O3 decomposition was independent of the wavelength or intensity of the radiation and approximately independent of [Br2] and [O3]. Later Mungen and Spinks found the yield to be 30 at 1 °C independent of [O3] and only very slightly dependent on temperature, [Br2], and intensity. Experiments done at higher temperatures (> 20 °C) included water vapor as an inert gas to minimize the thermal reaction. Mungen and Spinks proposed a tentative reaction scheme involving several oxides of bromine as intermediates and wall reactions. However, the results are reasonably well explained by a mechanism analogous to that for the F2-O3 system, viz. 

Oxygen fluorides were described in Section 15.7. Iodine is the only halogen to form an oxide which is thermodynamically stable with respect to decomposition into its elements (equation 16.38). The chlorine and bromine oxides are hazardous materials with a tendency to explode. 

Halogenated (mostly Cl and Br) biocides (such as hypochloride or DBDMH, see Tab. 6.3-1) are the most commonly used chemicals for sanitizing water. They are strong oxidizers and, as dust and products of decomposition (below), irritate respiratory tracts. Therefore, airborne, inhalable fine particles and all dust must be avoided. This is also true for non-chlorine (or bromine) oxidizers that are used for the same... 

EXPLOSION and FIRE CONCERNS nonflammable NFPA rating (not rated) explosive reaction with crown ethers or potassium hydroxide violent reaction with lithium, sodium-potassium alloy, acetone, or bases incompatible with metals, caustic alkali, and strong oxidants decomposition emits highly toxic gases and vapors (such as hydrogen bromide and bromine) use dry chemical, carbon dioxide, water spray, fog or foam for firefighting purposes. 

B, products giving positive Tollen s Reagent tests were obtained. No attempts were made to isolate either 9A or 9B since previous work had indicated that such compounds were subject to decomposition, and bromine oxidation was attempted on the crude reaction mixture. For both systems, as bromine addition was carried out, a transient blue color was noticed and white precipitates appeared in the reaction mixtures. In order to obtain 11A and IIB in purer form, the precipitated crude polymer was subjected to Soxhlet extraction with ethanol. This was followed by azeotropic distillation of benzene over the insoluble products. These two purification steps removed most of the non-polymeric by-products including unreacted or partially reacted nitro compounds as well as water and ethanol. Both llA and IIB showed strong IR absorption at 1200 cm" characteristic of the trans nitroso dimer bond, and a medium sharp absorption... 

Elemental bromine that has been produced during oxidative decomposition of organic compounds by chromic-sulfuric acid, can be detected directly and in minimal amounts through reaction with -aminophenol. A blue water-soluble product results. The basis of the color reaction is that the initial oxidation product is -quinone imine which reacts with unaltered aminophenol to form an indamine. (See detection of j -aminophenol, Vol II page 517). 

If organic compounds containing halogen are heated with a mixture of potassium permanganate and concentrated sulfuric acid, oxidative decomposition occurs with production of free halogen. The latter. Like other strong oxidants, converts diphenylamine dissolved in concentrated sulfuric acid into a blue quinoidal compound. If, however, a saturated solution of diphenylamine in ethyl acetate that contains some trichloroacetic acid is used, only chlorine yields a blue coloration. Bromine and iodine produce a yellow color that can be discharged by means of sodium thiosulfate. 

Tribromoacetic acid [75-96-7] (Br CCOOH), mol wt 296.74, C2HBr302, mp 135°C bp 245°C (decomposition), is soluble in water, ethyl alcohol, and diethyl ether. This acid is relatively unstable to hydrolytic conditions and can be decomposed to bromoform in boiling water. Tribromoacetic acid can be prepared by the oxidation of bromal [115-17-3] or perbromoethene [79-28-7] with fuming nitric acid and by treating an aqueous solution of malonic acid with bromine. 

Rhenium Halides and Halide Complexes. Rhenium reacts with chlorine at ca 600°C to produce rheniumpentachloride [39368-69-9], Re2Cl2Q, a volatile species that is dimeric via bridging hahde groups. Rhenium reacts with elemental bromine in a similar fashion, but the metal is unreactive toward iodine. The compounds ReCl, ReBr [36753-03-4], and Rel [59301-47-2] can be prepared by careful evaporation of a solution of HReO and HX. Substantiation in a modem laboratory would be desirable. Lower oxidation state hahdes (Re X ) are also prepared from the pentavalent or tetravalent compounds by thermal decomposition or chemical reduction. 

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