677-69-0Relevant articles and documents
Synthesis of telogens and optimization of tetrafluoroethene telomerization process
Lewandowski, Grzegorz,Meissner, Egbert,Milchert, Eugeniusz
, p. 337 - 344 (2007/10/03)
The most advantageous technological parameters of tetrafluoroethene telomerization using 1-chloro-2-iodohexafluoropropane (telogen) towards the telomers n2-n4 or n1-n4 were experimentally established. The telomers n1-n4 were prepared with the yield of 48 mol% under the following conditions: temperature 170°C, the molar ratio of 1-chloro-2-iodohexafluoropropane to tetrafluoroethene equal to 1.2, the autoclave filling of 1.5 kg dm-3. The maximum yield of telomers n2-n4 amounted to 27 mol% when the molar ratio of telogen to tetrafluoroethene was decreased to 0.7 and the other parameters of synthesis remained the same. The optimum parameters for the synthesis of telogens: 1-chloro-2-iodohexafluoropropane and 2-iodoheptafluoropropane have been also determined.
Addition of some unreactive fluoroalkanes to tetrafluoroethylene.: Direct catalytic synthesis of F-butene-2
Petrov, Viacheslav A.,Krespan, Carl G.
, p. 199 - 204 (2007/10/03)
Condensation of trifluoromethanes, CF3X (X=H, Cl, Br, I), with tetrafluorethylene to form the corresponding F-n-propyl adducts have been carried out with aluminum chlorofluoride as catalyst. Yields of C3F7I and C3F7Br are especially good, making these useful perfluoropropyl intermediates readily available. Details of the reactions, especially the presence of low percentages of perfluoroisopropyl iodide and bromide in the products, are accounted for by proposed mechanisms involving halonium intermediates. Longer-chain primary iodides can also be added to tetrafluoroethylene, but the final products are predominantly fluoroolefins, with pentafluoroethyl iodide as a byproduct. In the case of the addition of C2F5I to tetrafluoroethylene, conditions for an efficient, low temperature dimerization of terafluoroethylene to F-butene-2 catalyzed by a combination of C2F5I/aluminum chlorofluoride have been defined. Evidence for an unusual transfer of I+ from the iodonium derivative of F-butene-2 to tetrafluoroethylene is presented.
Process for the preparation of fluoroolefins
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, (2008/06/13)
The invention concerns processes for the preparation of fluoroolefins, including a process for the deiodofluorination of an iodine containing fluorocarbon comprising contacting said iodine containing fluorocarbon with a fluoroolefin in the presence of an aluminum chlorofluoride catalyst.
Transformations of F-Alkyl Iodides and Bromides Induced by Nickel(0) Carbonyl
Krespan, Carl G.,Dixon, David A.
, p. 36 - 43 (2007/10/03)
Adducts of primary F-alkyl iodides with nickel carbonyl are formed readily in donor solvents and pyrolyze at 100-150 °C to give olefinic coupling products in high yield. The mechanism proposed to account for the observed chemistry involves preferential α-elimination of fluorine with formation of a carbenoid species complex coordinated to nickel. Differences in reaction paths among several types of substrate halides are rationalized on the basis of polarization of the Ni-C bond in the adducts. Support for these proposals is provided by state-of-the-art calculations.
Lewis acid catalyzed conjugated iodofluorination of fluoroolefins
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, (2008/06/13)
A process for the preparation of perfluoroalkyl iodides, especially perfluoroethyl iodide, by reaction of perfluorinated compounds which contain a carbon carbon double bond with ICl in HF solvent in the presence of Lewis acid catalysts. The compounds are used as telogens for the telomerization of tetrafluoroethylene to long-chain perfluoroalkyl iodides.
RELATIONSHIPS IN THE IODOFLUORINATION OF FLUOROOLEFINS IN THE IODINE-IODINE PENTAFLUORIDE-METAL FLUORIDE SYSTEM
Morozov, A. V.,Maksimov, B. N.
, p. 1224 - 1229 (2007/10/03)
On the basis of the results from investigation of the reaction of fluoroolefins with the components of the iodine-iodine pentafluoride-metal fluoride iodofluorinating system and kinetic and spectroscopic investigations a mechanism is proposed for the iodofluorination of fluoroolefins as the conjugate addition of iodine and fluorine with initial electrophilic attack on the multiple bond by the I2+ cation.The role of mass exchange during synthesis in a flow-type system is noted.
Pyrolysis of branched-chain perfluoroalkanes in the presence of halogens
Tonelli, Claudio,Tortelli, Vito
, p. 125 - 128 (2007/10/03)
The thermal decomposition of some highly branched perfluoroalkanes in the presence of molecular halogens (Cl2, Br2, I2) has been studied.The clear-cut cleavage of the most hindered carbon-carbon bond and the trapping by halogens of the intermediate radicals so formed account for the product distribution.Kinetic measurements support a mechanism based on homolytic rupture of the perfluoroalkanes as the rate-determining step, followed by the fast reaction of the intermediates with halogens.
MEASUREMENT OF RATE CONSTANTS AND EQUILIBRIUM CONSTANTS OF RI R + I AND I + RI I2 + R FOR R = C3F7, iso-C3F7, C6F13, CF3OCF2CF2, OR C3F7OCF2CF2
Skorobogatov, G. A.,Dymov, B. P.,Tedeev, R. Sh.
, p. 158 - 165 (2007/10/02)
The method of isothermal pyrolysis of an iodide RI can produce highly accurate data about the equilibrium constants and rate constants of the reactions RI R + I and I + RI R + I2, if the rate constant for recombination R + R -> R2 is known.Data on the absolute rate constants of the thermal dissociation of the iodides C3F7I, iso-C3F7I, C6F13I, CF3O(CF2)2I and C3F7O(CF2)2I, and also for their reaction with atomic iodine were obtained for the first time using this technique.The dissociation energies ED (R-I) are 212+/-2, 201+/-2, 202+/-2, 213+/-2, and 213+/-2 kJ/mole, respectively.
THERMOLYSIS AND UV-PHOTOLYSIS OF PERFLUORINATED IODO-ALKANES AND IODO-OXAALKANES: THERE IS A PREFERRED REACTION CHANNEL
Probst, Anton,Werner, Konrad von
, p. 163 - 173 (2007/10/02)
The thermal stability of perfluorinated iodides depends on their structure and decreases in the order of RFCF2CF2I>RFCF2CF(CF3)I>RFOCF(CF3)I=RFCF2C(CF3)2I.The major decomposition path consists of the elimination of an unsaturated compound (CF2=CF2, CF2=CF-CF3, O=CF-CF3, CF2=C(CF3)2, respectively) with concomitant formation of RFI.The highest selectivities were found for tertiary iodides and 2-iodo-3-oxaalkanes, whose decomposition is virtually irreversible.UV-photolysis of the iodo-compounds gave the same products as the thermolysis reactions.
