- The reaction of dioxygenyl salts with 13CO Formation of F13C(O)13C(O)F
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Oxalyl fluoride has been prepared directly in high yield from CO and the dioxygenyl salts O2[BF4] or O2[AsF6]. The formation of intermediate FCO radicals is indicated by differences in reaction rates and the observation of FC(O)OOC(O)F as a by-product. From the analysis of the NMR spectra of 13C enriched FC(O)C(O)F including selective irradiation experiments positive signs for both the FF (+50.6 Hz) and CC (+126.1 Hz) coupling constants are deduced. From the temperature dependency of 3J(FF), values of +70 Hz and -10 Hz are estimated for the trans- and cis-rotamers, respectively.
- Pernice,Willner,Eujen
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Read Online
- Fluorinated olefins and oleum
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Oleum has some advantages over pure sulfur trioxide and may be successfully used for preparation of beta-sultones from hexafluoropropene, 2H-pentafluoropropene, 6H-perfluoro-1-hexene and perfluoro(propylvinyl) ether (VE). Depending on the reaction conditi
- Cheburkov, Yuri,Lamanna, William M.
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p. 147 - 152
(2007/10/03)
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- Kinetics of the thermal decomposition of bis(trifluoromethyl) peroxydicarbonate, CF3OC(O)OOC(O)OCF3
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Thermal decomposition of bis(trifluoromethyl) peroxydicarbonate has been studied. The mechanism of decomposition is a simple bond fission, homogeneous first-order process when the reaction is carried out in the presence of inert gases such as N2 or CO. An activation energy of 28.5 kcal mol-1 was determined for the temperature range of 50-90°C. Decomposition is accelerated by nitric oxide because of a chemical attack on the peroxide forming substances different from those formed with N2 or CO. An interpretation on the influence of the substituents in different peroxides on the O-O bond is given.
- Burgos Paci, Maximiliano A.,Argueello, Gustavo A.,Garcia, Placido,Willner, Helge
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- Synthesis of vinyl ether compounds by pyrolysis of dimethyl perfluoro-2,7-dimethyl-3,6-dioxa-1,8-octanedioate
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Dimethyl perfluoro-2,7-dimethyl-3,6-dioxa-1,8-octanedioate (1) is pyrolyzed over Na2CO3, K2CO3, CaCO3, BaCO3 and ZnO to give mixtures containing perfluoro-3,6-dioxa-1,7-octadiene (2) and methyl perfluoro-2-methyl-3,6-dioxaoctanoate-7-ene (3).The pyrolysis conditions necessary to obtain these vinyl ethers require a higher temperature for the divalent metal compounds than for the monovalent.Increase in the pyrolysis temperature and decomposition time result in an increasing conversion of 1.At lower temperatures the pyrolysis product is mainly 3.However, the formation of 2 increases with increasing decomposition temperature.Dimethyl carbonate was found in the decomposition product of the pyrolysis of 1 over Na2CO3, K2CO3. - Keywords: Pyrolysis; Dimethyl perfluoroalkanedioate; Perfluorodivinyl ether; Methyl perfluorovinylalkanoate; Metal carbonate
- Takata, Kuniaki,Takesue, Masahiro,Iseki, Yuji,Sata, Toshikatu
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p. 163 - 168
(2007/10/03)
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- Perhalodioxins and Perhalodihydrodioxins
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Two perhalo-1,4-dihydrodioxins, representatives of a previously unknown class of compounds, have been synthesized and shown to exhibit unusual reactivity.In particular, reaction with oxygen is spontaneous and exothermic, and radical-catalyzed homopolymerization will proceed through a fluorinated double bond.Representatives of the perhalo-2,3-dihydro-1,4-dioxin class have also been prepared and found to have reactivity in general intermediate to that of the perhalodioxoles and acyclic trifluorovinyl ethers.Computational studies of the two systems established thatintroduction of the first double bond raises the energy substantially, while the second double bond results in a near-planar ring with dramatically increased energy content.
- Krespan, Carl G.,Dixon, David A.
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p. 3915 - 3923
(2007/10/02)
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- CW CO2 LASER DRIVEN OXIDATION OF SOME PERHALOGENOCYCLOALKENES
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The title reaction of hexafluorocyclobutene, 1,2-dichloro-3,3,4,4-tetrafluorocyclobutene and decafluorocyclohexene studied at total pressure 13.3 and 16 kPa yield oxalyl halides COX.COX (X = F, Cl) and C2F4 that undergo consecutive reactions to COF2, CO and X2.The oxidation of decafluorocyclohexene is preceded by retro-Diels-Alder decomposition affording hexafluorocyclobutene and C2F4.Two alternative mechanisms for the oxidation of the cyclobutenes are presented, one involving a novel cleavage of intermediary bicyclic dioxetanes.The decomposition of oxalyl fluoride into COF2 and CO is favored over its oxidation.
- Pola, Josef,Vcelak, Jaroslav,Chvatal, Zdenek
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p. 398 - 405
(2007/10/02)
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- Process for producing difluoroiodoacetyl fluoride
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A process for producing difluoroiodoacetyl fluoride comprises a step of producing an intermediate having a group of ICF2 CF2 OSO2 -- by reacting 1,2-diiodotetrafluoroethane with an oxidizing acid having S(VI) atom and a step of decomposing said intermediate into said product.
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