75-68-3Relevant articles and documents
Estimation of atmospheric lifetimes of hydrofluorocarbons, hydrofluoroethers, and olefins by chlorine photolysis using gas-phase NMR spectroscopy
Marchione, Alexander A.,Fagan, Paul J.,Till, Eric J.,Waterland, Robert L.,LaMarca, Concetta
, p. 6317 - 6322 (2008)
An empirical correlation has been derived between accepted atmospheric lifetimes of a set of hydrofluorocarbons and hydrofluoroethers and relative rates of reaction with photolyzed chlorine in excess at ambient temperature. These kinetic systems were studied by nuclear magnetic resonance (NMR) spectroscopy in the gas phase, marking the first application of NMR spectroscopy to this field. The square of the Pearson coefficient R for the linear correlation between observed reaction rates and accepted atmospheric lifetimes was 0.87 for compounds of lifetime less than 20 years. The method was extended to the study of ethene and propene; the rate of reaction of propene was found to be 1.25 times that of ethene at 23°C. The chief advantage of this method is its simplicity and reliance only on common tools and techniques of an industrial chemical laboratory.
Method of producing 1,1-difluoroethane and application thereof for the production of 1,1-difluoroethylene
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Page/Page column 2; 4, (2008/06/13)
Process for the manufacture of 1,1-difluoroethane by liquid-phase fluorination of 1,2-dichloroethane using hydrofluoric acid in the presence of a Lewis acid as catalyst and of FeCl3 as cocatalyst. Process for the manufacture of 1,1-difluoroethylene employing it.
γ-Alumina-supported boron trifluoride: Catalysis, radiotracer studies and computations
Klap?tke, Thomas M.,McMonagle, Fiona,Spence, Ronald R.,Winfield, John M.
, p. 1446 - 1453 (2008/09/19)
The irreversible adsorption of boron trifluoride on calcined γ-alumina and amorphous chromia, in both cases at room temperature, has been studied using [18F]-labelled BF3. Although the resulting γ-alumina surface has some catalytic activity for the room temperature fluorination by anhydrous HF of CH3CCl3 under static conditions, its activity is far lower than that of γ-alumina, which has been fluorinated with SF4, nominally at room temperature. A possible explanation for the observed behaviour is given.
Method of making difluoromethane, 1,1,1-trifluoroethane and 1,1-difluoroethane
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Page/Page column 3, (2010/02/14)
A process for the production of difluoromethane (HFC-32), 1,1,1-trifluoroethane (HFC-143a) and 1,1-difluoroethane (HFC-152a). In the process the following steps are employed: (a) providing a reaction vessel, (b) providing in the reaction vessel activated carbon impregnated with a strong Lewis acid fluorination catalys selected from halides of As, Sb, Al, TI, In, V, Nb, Ta, Ti, Zr and Hf, (c) activating the catalyst by passing through the activated carbon impregnated with a strong Lewis acid fluorination catalyst anhydrous hydrogen fluoride gas and chlorine gas, (d) contacting, in a vapor state in the reaction vessel containing the activated catalyst, hydrogen fluoride and one or more halogenated hydrocarbons selected from chlorofluoromethane, dichloromethane, 1,1,1-trichloroethane, vinyl chloride, 1,1-dichloroethylene, 1.2-dichloroethylene, 1,2-dichloroethane, and 1,1-dichloroethane for a time and at a temperature to produce a product stream comprising hydrofluorocarbon product(s) corresponding to the chlorinated hydrocarbon reactant(s), and one or more of hydrogen chloride, unreactacted chlorinated hydrocarbon reactant(s), under-fluorinated intermediates, and unreacted hydrogen fluoride, and (e) separating the hydrofluorocarbon product(s) from the product stream.
Catalyst and method for producing 1,1-difluoroethane
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, (2008/06/13)
The present invention relates to a catalyst for producing 1,1-difluoroethane (HCFC-152a) and producing method thereof. More particularly, it is to provide the catalyst prepared by impregnating palladium on the active carbon pretreated with an aqueous hydrogen fluoride solution and an aqueous hydrogen chloride solution in series and its use in the production of 1,1-difluoroethane (HCFC-142b) by dehydrochlorinating 1,1-difluoro-1-chloroethane at 240-300° C. in the supplying molar ratio of 2-6 (H2/HCFC-142b) with maximizing a selectivity toward the product of HCFC-152a.
Radical addition of iodine monochloride to vinylidene fluoride
Kharroubi,Manséri,Améduri,Boutevin
, p. 145 - 153 (2007/10/03)
The radical addition of iodine monochloride to 1,1-difluoroethylene or vinylidene fluoride (VDF) leading to a ClCF2CH2I (I)/ClCH2CF2I (II) mixture is described. Four different ways of initiation (thermal, photochemical, presence of radical initiators or redox catalysts) were used and all of them led to a high amount (≥98%) of isomer (I). The percentages of (I) and (II) isomers were determined by 19F NMR and they were also deduced from those of ClCF2CH3 and ClCH2CF2H obtained by selective reduction of the iodine atom of the product mixture, by tributylstannane. The reactivity of ICl to VDF and the high proportion of isomer (I) were interpreted by means of a thermodynamical approach from the enthalpy of formation of (I) and (II), respectively, determined by semi-empirical computations. In addition, heats of formation of both isomers and interactions between the SOMO of radicals and the HOMO of the fluoroolefin show that the mechanism of such a reaction occurs via the addition of I· to the less fluorinated side of VDF.
Generation of radical species in surface reactions of chlorohydrocarbons and chlorocarbons with fluorinated gallium(III) oxide or indium(III) oxide
Thomson
, p. 1881 - 1885 (2007/10/03)
The reactions of C1 and C2 chlorohydrocarbons and chlorocarbons have been studied with the Lewis acid catalysts fluorinated gallium(III) oxide and fluorinated indium(III) oxide, respectively. Product analysis shows chlorine-for-fluorine exchange reactions together with the formation of 2-methylpropane and its chlorinated analogues 2-chloromethyl-1,3-dichloropropane and 2-chloromethyl-1,2,3-trichloropropane. Reactivities of the chlorohydrocarbon probe molecules show fluorinated gallium(III) oxide to be a stronger Lewis acid than fluorinated indium(III) oxide. The formation of the symmetrical butyl compounds is consistent with the generation of surface radical species and is also consistent with a 1,2-migration mechanism operating within radical moieties at the Lewis acid surface.
Liquid phase fluorination process and fluorinated organic products resulting therefrom
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, (2008/06/13)
In an improved process and plant for carrying out liquid phase fluorination in the presence of a catalyst, consisting in reacting hydrofluoric acid and an organic starting material in a reaction zone, and in separating, in a separating zone, reactional mixture and at least one light fraction containing the desired fluorinated organic products and at least a first part of the sub-fluorinated organic products formed, and a heavy fraction that includes the remainder of the sub-fluorinated organic products formed, and further comprising partial condensation of the said light fraction in order to obtain a gaseous phase containing the desired fluorinated organic products and a liquid phase containing said first part of the said sub-fluorinated organic products, said heavy fraction being returned to said reaction zone and said liquid phase being returned as a reflux to the top of the separation zone, intermediate recovery is carried out at, or in the proximity of, the lower portion of said separation zone.
CH3CF3-nCln haloalkanes and CH2=CF2-nCln halo-olefins on γ-alumina catalysts: reactions, kinetics and adsorption
Hess, A.,Kemnitz, E.
, p. 27 - 36 (2007/10/03)
The heterogeneously catalyzed reactions of the haloalkane, CH3CF(3-n)Cln, and halo-olefin, CH2=CF(2-n)Cl(n), series have been studied on a γ-alumina catalyst and the experimental results compared with calculated thermodynamic data.The main reactions occurring in this system can be explained by the following reaction paths: dehydrohalogenation, hydrohalogenation, F/Cl and Cl/F exchange with hydrogen halides.Dismutation reactions which are observed in other halocarbon series are unimportant in this system.A survey of the dominant reactions is given.In addition, the kinetic behaviour of CH3CF2Cl on the γ-alumina catalyst and the adsorption of various halocarbons have been investigated.The isosteric enthalpies of adsorption demonstrate that the interaction between the haloalkanes and the solid surface is more dominant than simple condensation. - Keywords: Chlorofluorocarbons; γ-Alumina catalysts; Heterogeneous catalysis; Kinetics; Adsorption; Enthalpy of adsorption
Process for the purification of 1,1-dichloro-1-fluoroethane
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, (2008/06/13)
A process for purification of crude, 1,1-dichloro-1-fluoroethane includes the steps of treating a mixture of crude, 1,1-dichloro-1-fluoroethane and hydrogen fluoride with chlorine in the presence of a Lewis acid, and distilling to recover purified 1,1-dichloro-1-fluoroethane, wherein hydrogen fluoride is present during the treatment with chlorine at a ratio of at least 5% by weight with respect to the mixture of crude, 1,1-dichloro-1-fluoroethane and hydrogen fluoride.
