- Formation of octachlorostyrene during the synthesis of chromium(iii) chloride
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Octachlorostyrene has been recovered from the reaction tube, along with previously reported hexachlorobenzene, during the synthesis of CrCl3 from Cr2O3 and CCl4 at high temperature. The region in the reaction tube where the octachlorostyrene was found, namely upstream from the Cr2O3 held at 890°C, suggests that this molecule is formed at a temperature below 890°C and that it decomposes if raised to that temperature. A low gas flow was used in this experiment, allowing products to diffuse countercurrently. Copyright
- Mataruse,Yuknis,McDonald,Booth,Cleary,Twamley
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- Organochlorine formation in magnesium electrowinning cells
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The formation of organochlorines during the electrolytic production of magnesium was investigated using a laboratory-scale electrolytic cell having a graphite anode, a liquid aluminium alloy cathode, and a molten chloride electrolyte. The cell was operated at current densities ranging from 3000 to 10,000 A m-2 and at temperatures ranging from 660°C to 750°C. Organochlorines were adsorbed from the cell off-gases onto silica gel, extracted with hexane, and determined by gas chromatography. All compounds identified were fully chlorinated aliphatic and aromatic compounds, the major components being hexachlorobutadiene, hexachlorobenzene, hexachloroethylene, and octachlorostyrene. The total amount of organochlorines per tonne of magnesium produced decreased with electrolysis time and with current density and increased with operating temperature; it was also dependent on the type of graphite employed. The output of organochlorines Varied from 5 to 20 g t-1 of magnesium.
- Deutscher,Cathro
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p. 147 - 155
(2007/10/03)
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- Influence of elemental sulfur on the de-novo-synthesis of organochlorine compounds from residual carbon on fly ash
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Thermal experiments between 300°C and 500°C were performed with fly ash of a municipal waste incineration plant which had been spiked with elemental sulfur. The influence of elemental sulfur on the heterogeneous carbon-decomposition and the de-novo-synthesis of polychlorinated compounds was investigated. Compounds such as polychlorinated dibenzodioxins, dibenzofurans, benzenes, benzoand dibenzothiophenes, Cl4-thiophene, Cl4- thienothiophene, Cl7- and Cl8-phenylthiophene were quantified. Apart from those, other intermediate structures were determined. These compounds are mainly aromatics with a vinyl- or butadienyl-group, stabilized by perchlorination. In detail, the compounds are Cl7- and Cl8-styrene, Cl10-vinylnaphthalenes, Cl10-phenylbutadiene, Cl10-octatetraene, Cl10-bis-butadienylsulfides and Cl12-stilbenes.
- Bechtler,Stieglitz,Zwick,Will,Roth,Hedwig
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p. 2261 - 2278
(2007/10/03)
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- Formation of octachloroacenaphthylene in the pyrolysis of decachlorobiphenyl
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The pyrolytic degradation of decachlorobiphenyl (PCB 209) in the temperature range of 700-1000°C and at a pyrolysis time of 10 seconds generated one main chloroaromatic product. This compound has been identified by HPLC-UV, GC-MS, GC-FTIR and 13C-NMR as octachloroacenaphthylene (OCAN). The mechanism of the nearly quantitative formation of octachloroacenaphthylene (OCAN) occurs via a nonachlorobenzobarrylene radical (Z1R) as an intermediate followed by a rearrangement and further dechlorination to form OCAN. Calculations with the program THERM based on the Benson-group-theory indicated that this mechanism is not possible for lower or nonchlorinated biphenyls.
- Bleise,Kleist,Guenther,Schwuger
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p. 655 - 666
(2007/10/03)
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- NOVEL PRODUCTS IN THE CO2-LASER INDUCED REACTION OF TRICHLOROETHYLENE
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Previous report on the thermal or CO2-laser induced decomposition of trichloroethylene have identified only one condensable product, hexachlorobenzene (in addition to HCl and mono- and dichloroacetylene).We have found that trichloroethylene vapor exposed to cw irradiation on the P(24) line of the (001-100) band of the CO2 laser at incident power levels from 8-17 W procedures numerous products, of which the 13 major ones have been identified using IR, GC/MS, GC/FTIR, and NMR methods.All of these products have 4, 6, or 8 carbons, are highly unsaturated, and are completely chlorinated or contain a single hydrogen.C4HCl5 and C6Cl6 isomers (three of each) account for ca. 55percent to 85percent of total products (based on peak area in the total ion chromatograms in GC/MS runs), depending on reaction conditions.In addition to characterizing the products, we discuss the dependence of the product distribution on laser power, irradiation time, and cell geometry, and we outline a possible mechanism.
- Earl, Boyd L.,Titus, Richard L.
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p. 104 - 114
(2007/10/02)
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- Thermolysis of phenoxyaluminum compounds and formation of PCDD/F and their precursors
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Within the study of the formation of chlorinated dioxins and dibenzofurans and their precursors the thermolysis of hexachloroethane over the aluminum melt was investigated. "De novo" synthesis of precursors of PCDD/F was studied in the model system AlCl3/elemental carbon. Totally chlorinated heterocyclic compounds have been detected parallel with the formation of organochlorine compounds. The possibility of inserting oxygen to aluminum organyls was presented. In order to gain more detailed knowledge of the catalytic behaviour of fly ash the chemistry of thermolysis of phenoxy- and chlorophenoxy aluminum compounds at 300°C with the presence and absence of Al2O3 was investigated. Reagent compounds and products of thermolysis were followed by mass spectrometry.
- Voncina,Medved,Zerjal
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p. 2029 - 2038
(2007/10/03)
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- Synthesis and Chemical Behavior of Perchlorophenylacetylene
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Perchlorophenylacetylene (6) is synthesized in three steps: (1) vicinal reductive dechlorination of perchlorostyrene (1) to (pentachlorophenyl)acetylene (2), (2) conversion of 2 into its silver acetylide (7), and (3) chlorination of 7 to 6.Some thermal an
- Ballester, Manuel,Castaner, Juan,Riera, Juan,Tabernero, Ignacio
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p. 1413 - 1419
(2007/10/02)
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- Syntheses with Halogen Derivatives of Thiophene and Benzothiophene
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Pyrolysis of octachlorotetrahydrothiophene 1,1-dioxide provides a practical synthesis of octachlorocyclobutane. 1,2-Dichlorohexafluorotetrahydrothiophene 1,1-dioxide also yields a cyclobutane.Treatment of these sulfones with potassium hydroxide forms perhalogenated 3-butenesulfonates.From octachloro-2,3-dihydrobenzothiophene 1,1-dioxide, octachlorostyrene is produced by pyrolysis and hexachlorobenzothiophene 1,1-dioxide by treatment with sodium iodide.Hexachlorobenzothiophene has been prepared from octachloro-2,3-dihydrobenzothiophene and oxidized with chromium trioxide to a thiolactone (17).Hydrolysis of the latter gives a 2H-benzothiete (18).Oxidation of tetrachlorothiophene forms the thiolactone tetrachloro-2,3-dihydrothiophen-2-one (19).Octachlorodibenzothiophene can be made by direct chlorination.
- Raasch, Maynard S.
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p. 2151 - 2155
(2007/10/02)
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