- Selective fluorination of dichloromethane by highest oxidation state transition-metal oxide fluorides
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In contrast to the reactivity of high oxidation state binary transition-metal fluorides with organic solvents, many transition-metal oxide fluorides do not react with CH2Cl2. Only the highest oxidation state species react, at temperatures below room temperature, via Cl-F exchange with > 90% selectivity, affording unstable high oxidation state chloro complexes which decompose to chlorine and lower oxidation state species.
- Holloway, John H.,Hope, Eric G.,Townson, Paul J.,Powell, Richard L.
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Read Online
- The reactions of xenon difluoride with "inert" solvents
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The reactions of XeF2 with a variety of organic solvents are dscribed.XeF2 is found to undergo both hydrogen-and chlorine-fluorine exchange over a relatively short timescale with chloroform, dichloromethane and dibromomethane.XeF2 reacts very slowly with tetrachloromethane and fluorotrichloromethane, although the addition of a catalitic amount of Hf increases the rate of reaction considerably.XeF2 dissolves in acetonitrile with negligible reaction to the extent of 2.25 mol kg-1.
- Dukat, Wolfgang W.,Holloway, John H.,Hope, Eric G.,Townson, Paul J.,Powell, Richard L.
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Read Online
- Selective reduction of a C–Cl bond in halomethanes with Et3GeH at nanoscopic Lewis acidic Aluminium fluoride
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The selective activation of C–Cl bonds of hydrochlorofluoromethanes and chloromethanes at moderate reaction conditions using ACF in a combination with Et3GeH is presented. The reactions of the chloromethanes (CH3Cl, CH2Cl2, CHCl3 and CCl4) in the presence of Et3GeH and ACF as catalyst led to the activation of only one C–Cl bond resulting in the hydrodechlorination. Friedel-Crafts reactions with benzene as solvent are suppressed by Et3GeH. A selective hydrodechlorination of hydrochlorofluoromethanes was achieved, because a transformation of a C–F bond into a C–H bond by the combination of ACF with Et3GeH did not occur. Supporting PulseTA experiments illustrated the interaction between the solid catalyst and Et3GeH, the solvent benzene or CH2Cl2.
- Mei?ner, Gisa,Feist, Michael,Braun, Thomas,Kemnitz, Erhard
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p. 234 - 241
(2017/09/12)
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- METHOD FOR PRODUCING DIFLUOROMETHANE
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A method for producing difluoromethane, including the catalytic reaction of dichloromethane with hydrogen fluoride in the liquid phase, in the presence of chlorine, and in the presence of an ionic liquid catalyst consisting of the product of the reaction of antimony pentachloride with an organic salt having the general formula X+A, where A is a halide anion or hexafluoroantimonate, and X+ is a quaternary ammonium cation, quarternary phosphonium or ternary sulfonium. Further, equipment suitable for implementing said method.
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Paragraph 0121-0125
(2015/08/04)
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- Xenon(IV)-carbon bond of [C6F5XeF2]+; Structural characterization and bonding of [C6F5XeF2][BF4], [C6F5XeF2][BF4]·2HF, and [C6F5XeF2][BF4]· n NCCH 3 (n = 1, 2); And the fluorinating properties of [C6F5XeF2][BF4]
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The [C6F5XeF2]+ cation is the only example of a XeIV-C bond, which had only been previously characterized as its [BF4]- salt in solution by multi-NMR spectroscopy. The [BF4]- salt and its new CH3CN and HF solvates, [C6F5XeF2][BF4]·1.5CH3CN and [C6F5XeF2][BF4]·2HF, have now been synthesized and fully characterized in the solid state by lowerature, single-crystal X-ray diffraction and Raman spectroscopy. Crystalline [C6F5XeF2][BF4] and [C6F5XeF2][BF4]·1.5CH3CN were obtained from CH3CN/CH2Cl2 solvent mixtures, and [C6F5XeF2][BF4]·2HF was obtained from anhydrous HF (aHF), where [C6F5XeF2][BF4]·1.5CH3CN is comprised of an equimolar mixture of [C6F5XeF2][BF4]·CH3CN and [C6F5XeF2][BF4]·2CH3CN. The crystal structures show that the [C6F5XeF2]+ cation has two short contacts with the F atoms of [BF4]- or with the F or N atoms of the solvent molecules, HF and CH3CN. The lowerature solid-state Raman spectra of [C6F5XeF2][BF4] and C6F5IF2 were assigned with the aid of quantum-chemical calculations. The bonding in [C6F5XeF2]+, C6F5IF2, [C6F5XeF2][BF4], [C6F5XeF2][BF4]·CH3CN, [C6F5XeF2][BF4]·2CH3CN, and [C6F5XeF2][BF4]·2HF was assessed with the aid of natural bond orbital analyses and molecular orbital calculations. The 129Xe, 19F, and 11B NMR spectra of [C6F5XeF2][BF4] in aHF are reported and compared with the 19F NMR spectrum of C6F5IF2, and all previously unreported J(129Xe-19F) and J(19F-19F) couplings were determined. The long-term solution stabilities of [C6F5XeF2][BF4] were investigated by 19F NMR spectroscopy and the oxidative fluorinating properties of [C6F5XeF2][BF4] were demonstrated by studies of its reactivity with K[C6F5BF3], Pn(C6F5)3 (Pn = P, As, or Bi), and C6F5X (X = Br or I).
- Koppe, Karsten,Haner, Jamie,Mercier, Hlne P. A.,Frohn, Hermann-J.,Schrobilgen, Gary J.
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p. 11640 - 11661
(2015/01/16)
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- Method of making difluoromethane, 1,1,1-trifluoroethane and 1,1-difluoroethane
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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.
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Page/Page column 3
(2010/02/14)
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- A PROCESS FOR THE PRODUCTION OF DIFLUOROMETHANE
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A process for vapor phase fluorination of methylene chloride with anhydrous hydrogen fluoride (AHF) in the presence of a coprecipitated chromia-alumina impregnated with zinc salt as catalyst, removing (HCl) and heavier components by distillation, subjecting (HFC-32) rich cut to a further step of fluorination catalyst.
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- Process for the production of difluoromethane
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A process for vapor phase fluorination of methylene chloride with anhydrous hydrogen fluoride (AHF) in the presence of a coprecipitated chromia-alumina impregnated with zinc salt as catalyst, removing HCl and heavier components by distillation, subjecting HFC-32 rich cut to a further step of fluorination in the presence of a fluorination catalyst.
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- METHOD OF PRODUCING DIFLUOROMETHANE
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Disclosed is a method of producing difluoromethane (HFC-32), which comprises firstly reacting methylene chloride with hydrogen fluoride in gas phase at 280 to 340° C. in the presence of a fluorinated catalyst to produce chlorofluoro methane, and secondly reacting the chlorofluoro methane with hydrogen fluoride in liquid phase at 60 to 80° C. in the presence of an antimony chloride catalyst. The method is advantageous in that HFC-32 is produced in high yield under mild reaction conditions using a relatively small amount of energy.
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- Process for the manufacture of defluoromethane
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The subject of the invention is a continuous process for the manufacture of difluoromethane (F32) from methylene chloride (F30) and hydrogen fluoride in the presence of chlorine, in the gas phase, over a fluorination catalyst. According to the invention, the gas flow exiting from the reactor is subjected to a distillation in order to separate, at the top, a flow containing virtually all the HCl and at least 90% of the F32 produced by the reaction and, at the bottom, a flow containing at least 90% of the unconverted reactants (F31, F30 and HF) and the latter flow is recycled directly to the reactor, without any purification operation.
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Page/Page column 6-7
(2008/06/13)
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- Process for producing difluoromethane
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A process is disclosed for producing difluoromethane by fluorinating dichloromethane with hydrogen fluoride in a liquid phase in the presence of a catalyst, wherein the reaction is conducted at a temperature within the range from 80 to 150° C. under a pressure within the range from 8 to 80 kg/cm2using a mixture of antimony pentafluoride and antimony trifluoride, or antimony pentafluoride as the fluorinating catalyst. The process economically and safely produces difluoromethane from dichloromethane and hydrogen fluoride.
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Page column 4
(2008/06/13)
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- Process for the production of difluoromethane
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The present invention provides a vapor phase process for the production of difluoromethane, HFC-32. The process of this invention provides for the preparation of HFC-32 by a process that exhibits both good product yield and selectivity.
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Page column 4
(2008/06/13)
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- Generation of 'naked' fluoride ions in unprecedentedly high concentrations from a fluoropalladium complex
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An F-/Cl- ligand exchange in the stable organopalladium fluoro complex 1 generates naked fluoride ions in unusually high concentrations. The released Freadily fluorinates dichloromethane under exceedingly mild conditions and deprotonates chloroform to produce dichlorocarbene.
- Grushin, Vladimir V.
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p. 994 - 996
(2007/10/03)
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- High Oxidation State Binary Transition Metal Fluorides as Selective Fluorinating Agents
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High oxidation state transition metal fluorides are selective fluorinating agents for dichloromethane, those with d0 electronic configurations undergo hydrogen-fluorine exchange and metal reduction, while dn species undergo chlorine-
- Dukat, Wolfgang W.,Holloway, John H.,Hope, Eric G.,Rieland, Matthias R.,Townson, Paul J.,Powell, Richard L.
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p. 1429 - 1430
(2007/10/02)
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- Reactions of Halogenated Methanesulfonyl Chlorides with Trimethylamine and an Inverse Sulfene-Amine Adduct
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Starting from chlorofluoromethane (3), prepared by a convenient procedure, fluoromethanesulfonyl chloride (6) was synthesized easily and cleanly via the intermediate thioethers 4-chlorobenzyl fluoromethyl sulfide (4) or benzhydryl fluoromethyl sulfide (5) for the first time.Reaction of 6 with trimethylamine leads to an inverse amine-adduct 9a of fluorosulfene, which was characterized by transformation to (fluoromethyl)trimethylammonium chloride (10) and by oxidation to the sulfonate 11.The structure of 9a is discussed on the basis of spectroscopic data.Bromomethanesulfonyl chloride (17) similarly as chloromethanesulfonyl chloride leads to a dimeric adduct 18a of (bromomethylsulfonyl)sulfene and trimethylamine, which is characterized by its hydrolysis product 19a. 2,4-Dibromo-1,3-dithietane 1,1,3,3-tetraoxide (15) could not be detected, but has been prepared by another method.The products, resulting from the monohalogenmethanesulfonyl chlorides, can be explained by the intermediate existence of the monohalogensulfenes.Difluoro- (20) and dichloromethanesulfonyl chloride (24) gave no sulfeneamine adducts; 20 yields (difluoromethyl)trimethylammonium chloride and other products while from 24 under various conditions only trimethylammonium trichloromethanesulfinate (25) is formed.
- Rheude, Udo,Sundermeyer, Wolfgang
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p. 2208 - 2219
(2007/10/02)
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- DIE ELEKTROFLUORIERUNG VON CHLORMETHYLSULFOCHLORID
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The electrochemical fluorination of ClCH2SO2Cl was studied.The main products were CF4, CF3Cl, SO2F2, SF6, CF3SO2F and ClCF2SO2F.Also minor amounts of CF3H and CF2HCl were formed as well as traces of CFH2Cl and CF2H2 under certain conditions.The yield of ClCF2SO2F increased with descending temperature, concentration and current density.
- Sartori, P.,Habel, W.
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p. 265 - 276
(2007/10/02)
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