Hexabromo

Bismuth, tris(dipropyldithiophosphonium)-stereochemistry, 1, 81 Bismuthate, hexabromo-structure, 1,73 Bismuthate, hexachloro-structure, 1, 73 Bismuthate, hexaiodo-structure, 1, 73... 

A purchased sample of hexabromo DPF chromatographed coincident with peak 3 of Figure IB. The NMR data (Table 1) agreed with published data (refs. 3-6) and was consistent with the structural assignment of 2,2, 4,4, 5,5 hexabromo DPF. 

The mechanism is usually electrophilic (see p. 972), but when free-radical initiators (or UV light) are present, addition can occur by a free-radical mechanism. Once Br-or Cl- radicals are formed, however, substitution may compete (14-1 and 14-2). This is espiecially important when the alkene has allylic hydrogens. Under free-radical conditions (UV light) bromine or chlorine adds to the benzene ring to give, respectively, hexabromo- and hexachlorocyclohexane. These are mixtures of stereoisomers (see p. 161). ... 

Very little is known as yet of the chemistry of cyclopentadienylthallium(I) and the related compounds listed in Table I. The parent compound gives tribromocyclopentane on treatment with bromine and the hexabromo derivative with potassium hypobromite 112). By far the most important use discovered so far for these organothallium(I) compounds is the preparation of metallocenes and cyclopentadiene-transition metal complexes. These preparations are, in general, characterized by manipulative simplicity and high yields, and details of the reactions reported thus far are summarized in Tables II-IV. 

Sellstrdm U, A Kierkegaard, C de Witt, B Jansson (1998) Polybrominated diphenyl ethers and hexabromo-cyclododecane in sediment and fish from a Swedish river. Environ Toxicol Chem 17 1065-1072. 

The IrIV anion, [Ir(H20)Br5], oxidises ascorbic acid at 20.0 °C.51 This reaction is first order with respect to ascorbic acid concentration and first order with respect to the Irlv anion. Comparison of hexabromo-, hexachloro, aquopentachloro-, and di-aquotetracholoiridium(IV) reactions with ascorbic acid shows that replacing a halide ion with a water molecule increases the standard reduction potential of the IrIV complex and increases the rate of reaction. 

Ten grams (0.0134 mol) of solid potassium hexabromo-rhenate(IV)8 is added slowly to a vigorously stirred solution of 5.5 g. (0.032 mol) of silver nitrate in 50 ml. of concentrated nitric acid and 200 ml. of water. The slurry is stirred for 10 minutes after addition of the solid. After standing, the clear supernatant is decanted. The brown solid is transferred onto... 

Higher valency glycoclusters were also obtained by reaction of the hexabromo-methylated P3N3 scaffold derivative with di- or triazide building blocks containing a hydroxy anchoring function (Fig. 27). Corresponding deprotected dodeca- and... 

Potassium hexafluorotechnetate(IV), K TcFg, is obtained from potassium pertechnetate via the hexabromo derivative with subsequent fusion with KHF2 (28), and the electronic spectrum (see Table 5) has been measured... 

Guerra P, Eljarrat E, Barcelo D (2008) Enantiomeric specific determination of hexabromo-cyclododecane by liquid chromatography-quadrupole linear ion trap mass spectrometry in sediment samples. J Chromatogr A 1203 81-87... 

The novel, low-melting-point salt [N-pentylpyridinium][cJoso-CB11H12] has been used as solvent in several dehalogenations of mono- and polychlorides and -bromides, catalyzed by several Pd phosphine complexes [69]. The debromina-tion of hexabromo- and 1,2,4,5-tetrabromobenzene was accomplished quite rapidly, whereas the dechlorination of 1,2,4-trichlorobenzene proceeded more slowly, but with excellent selectivity to 1,2-dichlorobenzene. The system could be recycled at least seven times without noticeable decrease of activity. 

Eriksson P (1996) Developmental neurotoxicology in the neonate-effects of pesticides and polychlorinated organic substances. Arch Toxicol Suppl 18 81-88 Eriksson P, Viberg H, Fischer C, Wallin M, Frediiksson A (2002) A comparison of developmental neurotoxic effects of hexabromo cyclododecane, 2,2, 4,4, 5,5 -hexabromodiphenylether (PBDE 153) and 2,2, 4,4, 5,5 -hexachlorobiphenyl (PCB 153). Organohalogen Comp 57 389-392... 

Aza[60]fulleronium ion 28 has been isolated and characterized by X-ray crystallography via the oxidation of 2 with the radical cation hexabromo(phenyl)carbazole (HBPC ) in dry ODCB [27]. The counter-ion is the silver(I) complex carborane ion Ag(CBjjHgCl5)2]. The salt was crystallized as dark green crystals by diffusion of hexane vapor. The solid is reasonably air stable. has almost the same structure... 

Woodward, L. A., and M. J. Ware Vibrational spectra of the PtFj and the question of dir-dir bonding in the hexachloro- and hexabromo-platinate ions. Spectrochim. Acta 19, 775 (1963). 

A closer inspection of A. luteoviolaceus by different groups provided a further variety of highly active metabolites, tetrabromopyrrole, hexabromo-2,2 -bipyrrole, tetrabromobiphenol, several simple phenols including 4-hydroxy-benzaldehyde and n-propyl-4-hydroxybenzoate, violacein (5) and related pigments, and the extremely strong siderophore alterobactin [97]. 

Characteristic Hexabromobiphen yl Octabromobiphenyl Decabromobiph enyl 2,2, 4,4 5,5 -Hexabromo- biphenyl... 

Polybrominated Biphenyls. Information found in the literature regarding the physical and chemical properties of hexabromobiphenyl, oetabromobiphenyl, decabromobiphenyl, and 2,2, 4,4, 5,5 -hexabromo-biphenyl is presented in Table 4-4. The data for the properties listed inTable 4-4 may not be reliable because products of questionable purity were used by earlier investigators to derive them. For example, the water solubility of hexabromobiphenyl (Neufeld et al. 1977) was reported to be the same as that of FireMaster FF-1 (Getty et al. 1977), although FireMaster FF-1 contained only 84.4% (Robertson et al. 1983b) hexabrominated biphenyls. 

Polybrominated Biphenyls. Many of the relevant physical and chemical properties of the PBBs are not available (see Table 4-3). More data on the physical and chemical properties of hexabromobiphenyl are available relative to octabromo- and decabromobiphenyl. Even in the case of hexabromobiphenyl, not all relevant data are available, and the quality of data are questionable because the properties of FireMaster BP-6 have been reported as the properties of hexabromobiphenyls. More importantly, very limited data are available on the physical and chemical properties for the individual congeners of hexabromo-, octabromo-, and decabromobiphenyl. The absence of such important data as K, vapor pressure, and Henry s law constant, is a major impediment in the prediction of the environmental fate and transport of PBBs. 

Decabromobiphenyl Decabromodiphenyl ether Hexabromo-1, T-biphenyl Octabromobiphenyl Octabromodiphenyl ether p-Bromodiphenyl ether Pentabromodiphenyl ether... 

Decabromobiphenyl Decabromdiphenyl ether Hexabromobiphenyl Hexabromo-1, T-biphenyl Octabromobdiphenyl p-Bromodiphenyl ether Polybrominated biphenyl... 

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