Sulphur compounds, pyrolysis

DouglasA.G., Sinninghe DamsteJ.S., Fowler M.G., Eglinton T.I., de Leeuw J.W. (1991) Unique distributions of hydrocarbons and sulphur compounds released by flash pyrolysis from the fossilised alga Gloeocapsomorpha prisca., a major... 

In a simulation of the reaction of glucose and cellulose with hydrogen sulphide and polysulphide at ambient temperature in aqueous solution the formation of organic sulphur compounds was observed which yielded thiophene on pyrolysis/evaporation. By such a process carbohydrates in nature might be converted into sulphur compound which, being resistant to microbial attack, would be preserved in sediments. ... 

Sulphur.—Compounds Containing Bivalent Sulphur. Attempts to oxidize bistrifluoromethyl sulphide (conveniently prepared by pyrolysis of commercial bistrifiuoromethyl disulphide at 425—435 °C) to either the sulphoxide or the sulphone using the reagents ( i-(n C H4-CO)sOa-100°C, NOjCIO, NOa-u.v., or NOa-Oa-350°C have proved unsuccessful fluorination of the monosulphide with hot argentic or cobaltic fluoride gave trifluoromethyl-sulphur pentafluoride, while bis(trifluoromethyl)sulphur difluoride was formed at low temperatures with fluorine itself. " Bis(trifluoromethyl)-sulphur difluoride and several other bis(perfluoroalkyl)sulphur difluorides, obtained from the corresponding sulphides and chlorine monofluoride (see p. 162), have been converted into bisperfluoroalkyl sulphoxides ... 

Rubber has a structure intermediate between thermosets and thermoplastics, with molecular chains linked by sulphur bridges during vulcanization. In pyrolysis, the main material is tyre rubber, a compound of styrene- butadiene- and isoprene-based rubber (SBR), of carbon black, sulphur, vulcanization aids, and zinc oxide. 

Compounds containing arsenic which are unstable in oxygen or moist air can be stabilized by exposure to sulphur for 8-48 h in vacuo. The resulting compounds may be analysed by pyrolysis for sulphur and arsenic ... 

In an alternative procedure the decomposition is effected by the use of concentrated sulphuric acid and potassium sulphate, followed by the addition of 30% hydrogen peroxide. The solution is adjusted to 6 N with respect to hydrochloric acid and antimony is extracted with diisopropyl ether. Colour is developed by the addition to the ether phase of 0.02% Rhodamine B in IN hydrochloric acid . Compounds containing trivalent antimony which are unstable in oxygen or moist air may be stabilized by exposure to sulphur for 8-48 h in vacuo and the resulting compounds are examined by pyrolysis . 

Sulphur-Nitrogen Compounds.—Linear Compounds. Results from ab initio Hartree-Fock calculations on the ground states of NSF and SSO have been reported.87 The photoelectron spectra of the bent, triatomic molecules NSF, SSO, 03, S02, and NSC1 were compared and experimental details of the photoelectron spectrum of SSO presented. Pyrolysis of the tetrathiatriazyl halide S4N3X at low pressures gives the corresponding thiazyl halide XSN where X = C1 or Br but not where X = I 88... 

Phosphorus(v) Compounds. X-Ray p.c. spectra for many phosphoryl and thiophosphoryl compounds have been analysed to give a series of substituent constants which accurately reproduce the experimental data/ There is now strong evidence for a monomeric metaphosphate, isoelectronic with sulphur trioxide, from pyrolysis experiments on methyl but-2-enyl phostonate (90)/ The... 

The utility of the Chugaev elimination for the formation of olefins without rearrangement of the carbon skeleton can be observed upon pyrolysis of the xanthate of alcohol 14.17 The desired vinyl cyclopropane (IS) was isolated in reasonable yield (42%) along with a small amount of the rearranged xanthate. Alternatively, acid-mediated dehydration with sulphuric acid yielded a variety of rearranged products in low yield. Ester pyrolysis (of the acetate of 14) also furnished a variety of compounds, with the major product being cyclopentene 16. 

Chumachenko et al. [170] determined sulphur in organic compounds. After pyrolysis of the sample in the presence of saturated hydrocarbons, H2S is analysed by GC. The relative standard deviation is 0.08%. 

Sulphur-Nitrogen-Phosphonis Compounds.—Thermolysis of compounds of the t3rpe RgPCl N—SOgX (R = Cl, Me, or Ph X = F or Cl) has been shown 2 to result in the formation of the compounds R2P(0)C1 and [NS(0)X] . Pyrolysis of phosphorus-sulphur-nitride halides with longer chains yields, amongst others, the cyclic compounds (37) and (38). The... 

Diazotization. Diazonium salts of benzothiazoles have been useful in interconversions involving amino-derivatives of this ring system. 2-Fluoro-benzothiazoles are accessible by the diazotization of the corresponding 2-amino-compounds, followed by cautious pyrolysis of the isolated diazonium fluoroborate with potassium fluoride and sand under reduced pressure. The four isomeric sulphonic acids of 2-methylbenzothiazoles are obtainable from the amino-compounds by diazotization, followed by treatment with acetic acid saturated with sulphur dioxide in the presence of cupric chloride the resulting sulphonyl chlorides serve as source of the... 

The reductive pyrolysis of organic compounds in the presence of metals leads to the formation of the metal cyanide, which can be detected as Prussian blue (Fe4[Fe(CN)g]3) or by the copper(ii) acetate-benzidine test . Several metals and salts have been recommended for the fusion of the organic compound, e.g. potassium , sodium , magnesium mixed with potassium carbonate , zinc mixed with potassium carbonate , and a mixture of dextrose with sodium carbonate . When the compound contains sulphur the metal thiocyanate is also produced, which can be detected by ferric chloride . ... 

Sulphur Di-imides.—Preparation and Properties of SN). This and related sulphur-nitrogen compounds have created interest both in their preparation and their physical properties (see Vol. 5, p. 103). Pyrolysis of S4N4 gives either (SN) or depending on the reaction conditions. - The physical and spectroscopic... 

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