76-12-0Relevant articles and documents
High surface area chromium(III)fluoride – Preparation and some properties
Tav?ar, Ga?per,Skapin, Toma?
, p. 81 - 89 (2019/05/14)
Reaction of hydrated hydrazinium fluorochromate(III), [N2H6][CrF5]·H2O, with fluorine (F2)in anhydrous hydrogen fluoride (aHF)medium at room temperature yields completely amorphous CrF3-based materials with exceptionally high specific surface areas of 180–420 m2 g?1 (HS-CrF3). The stepwise reaction starts with the oxidative decomposition of the cationic part of the precursor with F2 that gives a CrF3 intermediate with low surface area. In the following step, part of Cr3+ is oxidized to Cr>3+, and in the presence of residual H2O/[H3O]+ species Cr>3+ fluoride oxides are formed. Formation of volatile chromium compounds, mainly CrO2F2, is apparently the key step in HS-CrF3 formation. Removal of these components from the final product reduces the oxygen content, and generates microporosity. The HS-CrF3 materials are completely amorphous with a bulk composition that is close to stoichiometric CrF3. Small amounts of Cr>3+ and oxygen in the final product very likely originate from the retained non-volatile CrOF3. The HS-CrF3 materials are Lewis acids and exhibit a high reactivity towards chlorofluorocarbons (CFCs)evidenced by substantial F/Cl exchange between CFCs and the solid fluoride. High reactivity of these new materials can be ascribed to their nanoscopic nature, exceptionally high surface area, and low levels of impurities. As such, they represent an interesting new class of benchmark fluoride materials applicable in fluorocarbon chemistry.
METHOD FOR PRODUCING 1-CHLORO-1,2-DIFLUOROETHYLENE
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Paragraph 0082; 0084, (2016/12/22)
PROBLEM TO BE SOLVED: To provide a method for efficiently and economically producing 1-chloro-1,2-difluoroethylene that can industrially be performed. SOLUTION: The method for producing 1-chloro-1,2-difluoroethylene comprises bringing 1,2-dichloro-1,2-difluoroethane into contact with an alkali aqueous solution in the presence of a phase transfer catalyst to thereby subject 1,2-dichloro-1,2-difluoroethane to dehydrochlorination reaction. COPYRIGHT: (C)2015,JPO&INPIT
PROCESS FOR THE SYNTHESIS OF PERFLUOROBUTADIENE
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Page/Page column 13, (2009/09/04)
Process for preparing perfluoro-1,3-butadiene, comprising the following steps : A) preparation of fluoro-halo-butanes of formula : CF2 YI-CFYIICFYIICF2 YI (V) in which YI and YII which may be identical or different, may be H, C1 or Br, with the condition that YI and YII are not simultaneously hydrogen; starting with a chloroolefin having the formula : CY'Y = CY'C1 (II) in which Y, Y', Y', which may be identical or different, are H, C1 or Br, with the condition that Y, Y', Y' are not simultaneously hydrogen; and performing the following steps : - a fluorodimerization, and - a fluorination with elemental fluorine, the order of the two steps also possibly being inverted, - a dehalogenation or dehydrohalogenation step being performed between the two steps, B) dehalogenation or dehydrohalogenation of the fluoro-halo compounds of formula (V) to give the compound perfluoro-1,3-butadiene.
Process for preparing fluorohalogenethers
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Page/Page column 10, (2008/06/13)
A process for preparing perfluorovinylethers having general formula: ???????? RfO-CF=CF2?????(IA) wherein Rf is a C1-C3 alkyl perfluorinated substituent; comprising the following steps: 1a) fluorination with fluorine of olefins of formula: ???????? CY"Y=CY'Cl?????(II) wherein Y, Y' and Y", equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y' and Y" are not contemporaneously hydrogen; and obtainment of fluorohalogencarbons of formula: ???????? FCY"Y-CY'ClF?????(III) wherein Y, Y' and Y" are as above; 2a) dehalogenation or dehydrohalogenation of the fluorohalogencarbons (III) and obtainment of fluorohalogen olefins of formula: ???????? FCYI=CYIIF?????(IV) wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H; 3a) reaction between a hypofluorite of formula RfOF and a fluorohalogenolefin (IV), obtaining the fluorohalogenethers of formula: ???????? RfO-CFYI-CF2YII?????(I) wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H; 4a) dehalogenation or dehydrohalogenation of the compounds (I) and obtainment of the perfluorovinylethers (IA).
Process for preparing fluorohalogenethers
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Page/Page column 5, (2008/06/13)
A process for preparing perfluorovinylethers having general formula: [in-line-formulae]RfO—CF═CF2 ??(IA)[/in-line-formulae] wherein Rf is a C1-C3 alkyl perfluorinated substituent; comprising the following steps: 1a) fluorination with fluorine of olefins of formula: [in-line-formulae]CY″Y═CY′Cl ??(II)[/in-line-formulae]wherein Y, Y′ and Y″, equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y′ and Y″ are not contemporaneously hydrogen; and obtainment of fluorohalogencarbons of formula: [in-line-formulae]FCY″Y—CY′ClF ??(III)[/in-line-formulae]wherein Y, Y′ and Y″ are as above; 2a) dehalogenation or dehydrohalogenation of the fluorohalogencarbons (III) and obtainment of fluorohalogen olefins of formula: [in-line-formulae]FCYI═CYIIF ??(IV)[/in-line-formulae]wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H; 3a) reaction between a hypofluorite of formula RfOF and a fluorohalogenolefin (IV), obtaining the fluorohalogenethers of formula: [in-line-formulae]RfO—CFYI—CF2YII ??(I)[/in-line-formulae]wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H; 4a) dehalogenation or dehydrohalogenation of the compounds (I) and obtainment of the perfluorovinylethers (IA).
Dynamic behaviour of chlorofluoroethanes at fluorinated chromia aerogels and fluorinated zinc(II) or magnesium(II) doped chromia aerogels
Bozorgzadeh, Hamid,Kemnitz, Erhard,Nickkho-Amiry, Mahmood,Skapin, Toma?,Winfield, John M.
, p. 83 - 92 (2007/10/03)
The preparation and characterisation of two series of fluorinated chromia aerogel materials, lightly doped with zinc(II) or magnesium(II), are described. They behave as heterogeneous catalysts for transformations of 1,1,2-trichlorotrifluoroethane under HF
Kinetics and mechanism of the thermal gas-phase oxidation of tetrachloroethene by molecular oxygen in presence of trifluoromethylhypofluorite, CF3OF
Czarnowski, Joanna
, p. 183 - 197 (2007/10/03)
The oxidation of tetrachloroethene by molecular oxygen in presence of CF3OF has been studied at 314.0, 324.2, 334.1 and 344.3 K. The initial pressure of CF3OF was varied between 2.0 and 8.2 Torr, that of CCl2CCl2 between 8.7 and 21.7 Torr, that of O2 between 33.2 and 730.7 Torr. Several runs were made adding N2 at pressure varying between 250.4 and 525.9 Torr. The major products were CCl3C(O)Cl and COCl2. CF3OCCl2C(O)Cl, CCl2FC(O)Cl, CF3OCCl2CCl2F and CCl2FCCl2F were formed in traces. The oxidation is a chain reaction. Its rate increases with total pressure. The following mechanism, where E = CCl2CCl2, R = CCl2FCCl2, CF3OCCl2CCl2 or CCl3CCl2, R′ = CCl2F, CF3OCCl2 or CCl3 and M = effective pressure, explains the experimental results: 1) CF3OF+E → R+CF3O 3, 7) R+O2+M → RO2+M 5) RO → R′C(O)Cl+Cl 9) CCl3CCl2O → CCl3C(O)Cl+Cl 11) CCl3+O2+M → CCl3O2+M 13) CCl3O → COCl2+Cl 15) R+CF3OF → RF+CF3O 2) CF3O+E → R 4, 8) 2RO2 → 2RO+O2 6) Cl+E → CCl3CCl2 10) CCl3CCl2O → CCl3+COCl2 12) CCl3O2+RO2 → CCl3O+RO+O2 14) 2R → recombination products, k9 = (3.0±1.4) × 1013 exp(-9.66±1 kcal mol-1/RT) s-1. by R. Oldenbourg Verlag, Muenchen 1998.
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.
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 (2007/10/03)
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.
Kinetics and mechanism of the thermal gas-phase reaction between trifluoromethylhypofluorite, CF3OF, and tetrachloroethene
Czarnowski
, p. 489 - 495 (2007/10/03)
The thermal gas-phase reaction of CF3OF with CCL2CCL2 has been studied between 313.8 and 343.8 K. The initial pressure of CF3OF was varied between 10.8 and 77.5 torr and that of CCl2CCl2 between 3.7 and 26.8 torr. CF3OF was always present in excess, varying the initial ratio of CF3OF to that of CCl2CCl2 from 1.3 to 10. Three products were formed: CF3OCCl2CCl2F, CCl2FCCl2F, and CF3O(CCl2CCl2)2OCF3. The yields of CF3OCCl2CCl2F were 98-99.5%, based on the sum of the products. The reaction was a homogeneous chain reaction not affected by the total pressure. In presence of O2 the oxidation of CCl2CCl2 to CCl3C(O)Cl and COCl2 occurred. The proposed basic reaction steps are: generation of the radicals CF3O· and CCl2FCCl2· (k1) in a biomolecular process between CF3OF and CCl2CCl2, formation of the radical CF3OCCl2CCl2· by addition of CF3O· to CCl2CCl2, chain generation of CF3O· by abstraction of fluorine atom from CF3OF by CF3OCCl2CCl2· (k4), and chain termination by recombination of the radicals CF3OCCl2CCl2·. The expressions obtained for the constants k1 and k4 are: k1 = 3.16 ± 0.6 × 107 exp(- 15.2 ± 1.7 Kcal mol-1/RT) dm3 mol-1 s-1; k4 = 3.7 ± 0.5 × 109 exp(- 6.0 ± 1.1 Kcal mol-1/RT) dm3mol-1s-1.
