Brominated organics

FeBr2 120 [13463-12-2] is commercially available. Anhydrous inon(II) bromide is used as a catalyst ia organic brominations and polymerization reactions. 

Waste HBr is a common byproduct of organic brominations. Frequently, this waste is neutralized with caustic, the resulting sodium bromide salt is discharged, and valuable bromine is lost. The economic advantages of recovery and recycle of this HBr have long been recognized (refs. 1, 3). In practice, recovery typically takes the form of conversion of the HBr to clear drilling fluids or alkylbromides (ref. 4) as shown in equations 1 and 2. 

Orlando JJ (2003) Atmospheric chemistry of organic bromine and iodine compounds. Handbook Environ Chem 3R 253-299. 

Organic bromamines, 13 104-112 Organic bromine compounds, 4 340-362 aliphatic, 4 345-349 chemical reactions, 4 341—343 dyes and indicators, 4 361-362t, 362 flame retardants, 4 349, 354, 355—358t industrial chemical intermediates, 4 350—353t... 

Trace amounts of bromine in sodium diclofenac, sodium (2-[(2, 6-dichlorophenyl)amino] phenyl acetate, have been determined using XRF [82], since the drug substance should not contain more than 100 ppm of organic bromine remaining after the completion of the chemical synthesis. Pellets containing the analyte were compressed over a boric acid support, which yielded stable samples for analysis, and selected XRF spectra obtained in this study are shown in Fig. 7.19. It was found that samples from the Far East contained over 4000 ppm of organic bromine, various samples from Europe contained about 500 ppm, while samples from an Italian source contained less than 10 ppm of organic bromine. 

Fig. 7.19. XRF spectra of pure diclofenac (lower trace), and diclofenac containing organic bromine (upper trace). The bromine Ko, peak is the markeod peak at 1.04 A, while the bromine Kp peak is the marked peak located at 9.93 A. The figure was adapted from data in Ref. [82].

L. Bj ellerup. On the Accuracy of Heat ofCombustion Data Obtained with a Precision Moving-Bomb Calorimetric Method for Organic Bromine Compounds. Acta Chem. Scand. 1961,15, 121-140. 

L. Smith, L. Bjellerup. Combustion in a Bomb of Organic Bromine Compounds. In Experimental Thermochemistry, vol. 1 F. D. Rossini, Ed. Interscience New York, 1956 chapter 9. 

Hwang, S. C., Larson, R.A., and Snoeyink, V.L. Organic bromine as a source ofelectrophilic bromine in aqneons chlorination reactions, Chemosphere, 17(7) 1337-1342,1988. 

Figure 12.44 shows the major organobromine compounds measured at the earth s surface from 1988 to 1996 (Wamsley et al., 1998). These compounds have also been measured at the tropopause in the tropics, i.e., at the point at which the air is believed to enter the stratosphere. Methyl bromide and the halons are the major species obseived. For example, in one set of measurements, of 17.4 ppt organic bromine, 55% was from CH3Br, 38% from the halons, 6% from CH2Br2, and 0.8% from the combination of CH2BrCl and CHBrCl2 (Schauffler et al., 1998). 

FIGURE 12.44 Organic bromine compounds observed at the earth s surface from 1988 to 1996 (adapted from Wamsley et al., 1998). 

Material balances for the pyrolysis products from HIPS equipped with flame retardants have been given (53). The pyrolysis experiments were performed to some extent in the presence of zeolite catalysts. The zeolites were added in order to remove organic bromine from the products of pyrolysis. In addition to their potential of destroying toxic brominated flame retardants, zeolites have been believed to be suitable to upgrade the pyrolysis products. 

The zeolite catalysts are very effective in removing volatile organic bromine. However, they are not very effective in removing antimony bromide from the volatile pyrolysis products. Actually, the zeolites cause a dramatic increase of the formation of hydrogen by a factor of 10. In addition, zeolite catalysts were found to reduce the formation of some valuable pyrolysis products, such as styrene and cumene, but other products, such as naphthalene were formed instead (53). 

Sulphuric Acid, Chlorine, and Organic Bromine Compounds (Bromoform Carbon Tetrabromide). — 5 gm. of bromine dissolve without turbidity of any kind in 100 cc. of wat r after adding, by drops, 20 cc. of ammonia water. Evaporate to dryness the solution of ammonium bromide thus obtained, and test for ... 

Organic bromine compounds gradually separate out in the form of oily drops. 

Organic bromine has a zero tolerance because of the reported toxicity of monobromacetic acid. It can be extracted quantitatively with ether at pH 1. The determination is then the same as with total bromide (4). 

A -Bromosuccinimide (NBS) is a convenient organic brominating agent. In combination... 

Carpenter LJ, Liss PS (2000) On Temperate Sources of Bromoform and Other Reactive Organic Bromine Gases. J Geophys Res 105 20539... 

In 1957, Golub [47] first reported the cis-trans isomerisation of an unsaturated macromolecule. He showed the successful transformation of the cis 1,4 BR into corresponding trans units by means of ultraviolet irradiation in the presence of a suitable sensitiser, which may be any one of a wide variety of organic bromine or sulfur compounds. In the photoisomerisation of BR or other diene elastomers, there is direct excitation of 7t-electrons of the double bonds to an antibonding state in which free rotation and hence geometrical interconversion can occur. 

Test for Carbromal and Other Organic Bromine Compounds... 

Acidify a portion of stomach contents with 2M hydrochloric acid, and extract with four times its volume of chloroform evaporate the extract to dryness, dissolve the residue in 0.5 ml of ethanol, transfer the solution to a white porcelain dish, add 2 drops of 2M sodium hydroxide, and dry with gentle heat. Cool, add 2 drops of a 1% solution of fluorescein, 4 drops of acetic acid, and 4 drops of strong hydrogen peroxide solution, and evaporate to dryness on a boiling water-bath. A red colour, due to eosin, indicates the presence of carbromal, bromvaletone, or other organic bromine compounds. 

Hydrobromic acid is used in the production of inorganic bromides as well as in organic brominations, particularly in the production of pesticides. Some physical properties of the hydrohalide acids are summarized in Table 6. 

What all flame retardants have in common is that they start to decompose when heated. A critical factor in the selection of a flame retardant is therefore its thermal stability with respect to that of the polymer. The ideal situation is when the flame retardant decomposes at about 50 % below the combustion temperature of the polymer. This is the case with most organic bromine compounds and most synthetic polymers [1]. In addition, brominated flame retardants are economically feasible, and they have little effect on the flexibility of the base compounds [16]. Because of the advantages mentioned above, the commercial use of brominated compounds is attractive. 

Carpenter L. J. and Liss P. S. (2000) On temperate sources of bromoform and other reactive organic bromine gases. J. Geophys. Res. 105, 20539-20547. 

Commercial bromine usually contains chlorine, iodine and some organic bromine compounds. 

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