1717-00-6Relevant articles and documents
Substituent effects and threshold energies for the unimolecular elimination of HCl (DCl) and HF (DF) from chemically activated CFCl2CH3 and CFCl2CD3
McDoniel, J. Bridget,Holmes, Bert E.
, p. 3044 - 3050 (1996)
Combination of CFCl2 and methyl-d0 and -d3 radicals form CFCl2CH3-d0 and -d3 with 100 and 101 kcal/mol of internal energy, respectively. An upper limit for the rate constant ratio of disproportionation to combination, kd/kc, for Cl transfer is 0.07 ± 0.03 for collision of two CFCl2 radicals and 0.015 ± 0.005 for CH3 and CFCl2 radicals. The chemically activated CFCl2CH3 undergoes 1,2-dehydrochlorination and 1,2-dehydrofluorination with rate constants of 3.9 × 109 and 4.9 × 107 s-1, respectively. For CFCl2CD3 the rate constants are 8.7 × 108 s-1 for loss of DCl and 1.1 × 107 s-1 for DF. The kinetic isotope effect is 4.4 ± 0.9 for HCl/DCl and appears to be identical for HF/DF. Threshold energies are 54 kcal/mol for loss of HCl and 68 kcal/mol for HF; the E0's for the deuterated channels are 1.4 kcal/mol higher. Comparison of these threshold energies with other haloethanes suggests that for HF and HCl elimination the transition states are developing charges of different signs on the carbon containing the departing halogen and that chlorine and fluorine substituents exert similar inductive effects.
Liquid-phase fluorination of 1,1,1-trichloroethane
Brunet, S.,Batiot, C.,Barrault, J.,Blanchard, M.
, p. 33 - 39 (1992)
The reaction of HF with SbCl5 at 60 deg C and 1 MPa provides antimony mixed halides whose empirical formulae have been determined.The product is a mixture of SbClF4 and SbClF2 solvated by HF and its activity has been measured for the conversion of 1,1,1-trichloroethane (F140a) into mono- and difluorochloroethane (F141b and F142b).
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.
Production of organic fluorine compounds
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, (2008/06/13)
A process is disclosed for hydrofluorinating an olefinic hydrocarbon of the formula where X, X' and X" are the same or different and are hydrogen or halo and R' is hydrogen or C1 -C6 alkyl, with hydrogen fluoride. The process is carried out by admixing the olefinic hydrocarbon with hydrogen fluoride in an imidofluoride hydrogen fluoride solvent having the formula where R is C1 to C6 alkyl, C1 to C6 alkyl substituted with halo or C6 to C10 aryl either unsubstituted or substituted with alkyl and η is 0 or an integer that is at least 1.