The Preparation and Some Properties of the C4F8 Olefins1

Brice, T. J.; LaZerte, J. D.; Hals, L. J.; Pearlson, W. H.

doi:10.1021/ja01107a044

Cited by 61 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fact that TFE and perfluorocyclobutane exist as equilibrium mixture under the condition was also noted by Atkinson and Atkinson [3]. The formation of PFIB is favored at higher temperature (850-900 8C) where radical recombinations are postulated to favor the formation of branched chain structure instead of straight chain or ring [1]. At even higher temperature (>950 8C) PFIB and other lower olefins disproportionate to yield mainly perfluoroethane (Scheme 1) [3].…”

Section: Discussionmentioning

confidence: 74%

See 1 more Smart Citation

Flash pyrolysis of polytetrafluoroethylene (teflon) in a quartz assembly

Bhadury

Singh

Sharma

et al. 2007

Journal of Analytical and Applied Pyrolysis

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 74%

“…tetrafluoethylene, perfluorocyclobutane, hexafluoropropene, polytetrafluoroethylene (PTFE, teflon) and sodium or potassium salts of n-perfluorovaleric acid are important techniques for obtaining volatile fluorocarbons [1][2][3][4][5][6]. Safe collection, storage and analysis of these fluorinated volatiles have always been a problem.…”

Section: Introductionmentioning

confidence: 99%

Flash pyrolysis of polytetrafluoroethylene (teflon) in a quartz assembly

Bhadury

Singh

Sharma

et al. 2007

Journal of Analytical and Applied Pyrolysis

View full text Add to dashboard Cite

“…The C 4 F 8 olefin was assigned [16] as predominantly the i-isomer, with only traces of the 2-isomer and none of the 1-isomer, based on IR spectra. This assignment is supported by an earlier preparative-scale flow thermolysis of c-C 4 F 8 (90% conversion) at 720 • C in a carbon-lined tube from which Brice and coworkers [18] reported a 70% isolated yield of i-C 4 F 8 with a much lower 5-10% yield of 2-C 4 F 8 , the isomers being separated by fractional distillation. The i-, 2-(Z-E mixture), and 1-C 4 F 8 isomers had distinguishable IR spectra and were identified chemically by oxidative cleavage of their double bonds.…”

Section: Medium-temperature Regimementioning

confidence: 81%

Chain elongation during thermolysis of tetrafluoroethylene and hexafluoropropylene: Modeling of mechanistic hypotheses and elucidation of data needs

Poutsma

2011

Journal of Analytical and Applied Pyrolysis

View full text Add to dashboard Cite

“…Since CF3CH3 and CzH6 were found in appreciable amounts in the products from experiments with methane as substrate it is reasonable to assume that the methyl radicals produced in reaction [3] …”

Section: Inmentioning

confidence: 99%

The Vapor Phase Photolysis of Hexafluoroacetone in the Presence of Methane and Ethane

Ayscough¹,

Polanyi²,

Steacie³

1955

Can. J. Chem.

View full text Add to dashboard Cite

The photolytic decomposition of hexafluoroacetone by light of wavelength 3130 A has been used to produce trifluoromethyl radicals for a study of their reactions with methane and ethane. I t has been shown that these radicals abstract hydrogen with greater facility than do methyl radicals. The activation energies for the two reactions CFa+CHd+ CFaH+CHs and CFa+CnHs+ CFaH +CzHa are found to be 10.3 f 0.5 kcal./mole and 7.5 f 0.5 kcal./mole respectively, if one can assume zero activation energy for the recombination of trifluoromethyl radicals. INTRODUCTIONRelatively few kinetic studies have been made on the reactions of fluoroalkyl radicals and most of those so far reported have not yielded very precise data about the elementary reactions of these radicals. In part this is the result of analytical difficulties in haildliilg the mixtures of fluorinated compounds in the reaction products. Further difficulties have arisen because of low quantum yields (as in the photolysis of trifluoromethyl iodide (2, 4, 6)), side reactions caused b y the necessity of using high temperatures for pyrolyses (as in t h e pyrolysis of tristrifluoromethyl arsine (I)), or the production of more than one type of radical in the primary breakdown (as in the photolysis of trifluoroacetone (12)). Some exploratory work on the photolysis of hexafluorodimethyl mercury (11) showed that trifluoromethyl radicals were produced by straightforward fission of the mercury-carbon bonds but the total yield was small on account of the low volatility of the substrate.During a preliminary study of the photolysis of hexafluoroacetone it was found that this compound fulfills most of the requirements of a source of trifluoromethyl radicals and t h a t a simple analytical procedure can be devised for estimating the products. I t was therefore decided t o begin a study of the elementary reactions of these radicals with an investigation of their reactions with the simpler hydrocarbons, using the photolysis of hexafluoroacetone a s the source of the radicals.Between 80" and 300°C. hexafluoroacetone yields on photolysis only hexafluoroethane and carbon monoxide, in the stoichiometric proportions. The quantum yield is independent of light intensity and is only slightly affected b y pressure in the range used (20-100 mm.). I n the presence of hydrocarbons fluoroform is found in the products and under certain conditions replaces the hexafluoroethane almost completely. For instance when 25 mm. hexafluoroacetone is photolyzed a t 120°C. in the presence of an equal amount of isobutane lMa?zzrscript

show abstract

The Preparation and Some Properties of the C₄F₈ Olefins¹

Cited by 61 publications

References 0 publications

Flash pyrolysis of polytetrafluoroethylene (teflon) in a quartz assembly

Flash pyrolysis of polytetrafluoroethylene (teflon) in a quartz assembly

Chain elongation during thermolysis of tetrafluoroethylene and hexafluoropropylene: Modeling of mechanistic hypotheses and elucidation of data needs

The Vapor Phase Photolysis of Hexafluoroacetone in the Presence of Methane and Ethane

Contact Info

Product

Resources

About