- Synthesis, structure and conformational properties of fluoroformylchlorodifluoroacetyl disulfide, FC(O)SSC(O)CF2Cl: Conformational transferability in -C(O)SSC(O)- compounds
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Pure fluoroformylchlorodifluoroacetyl disulfide, FC(O)SSC(O)CF 2Cl, has been prepared by the reaction of FC(O)SCl and CF 2ClC(O)SH in quantitative yield. The conformational properties of the novel molecule have been studied by vibrational spectroscopy (IR - gas phase, Raman - liquid phase) and quantum chemical calculations (B3LYP and MP2 methods). The gaseous compound exhibits a conformational equilibrium at room temperature where the most stable form adopts a C1 symmetry and a syn-periplanar (sp) orientation of both carbonyl groups with respect to the disulfide bond. A second form, observed in the IR spectrum of the vapor, corresponds to a conformer in which the carbonyl bond of the FC(O) moiety adopts an anti-periplanar (ap) position with respect to the S-S single bond, and gauche with respect to the ClC-C=O moiety in the chlorodifluoroacetyl group. The experimental free energy difference value ΔG0 = G 0(ap-sp) - G0(sp-sp) = 1.4(3) kcal/mol (IR) is reproduced well by the B3YLP/6-311+G(3df) (1.1 kcal/mol) and the MP2/6-31G* (1.8 kcal/mol) methods. In addition, the structure of a single-crystal, grown in situ, was determined by X-ray diffraction analysis at low temperature. The crystalline solid [monoclinic, P21/n, a = 5.579(3) A, b = 16.615(7), c = 8.455(4) A, β = 106.876(8)°] consists exclusively of molecules with the (sp-sp) conformation and the usual gauche orientation around the disulfide bond [φ(CS-SC) = 84.2°]. Conformational transferability is thus demonstrated once again for species that contain the -C(O)SSC(O)- group as part of a systematic program designed to analyze the behavior of this class of molecules. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Erben, Mauricio F.,Della Vedova, Carlos O.,Willner, Helge,Boese, Roland
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- Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS: Preparation and structural and spectroscopic studies
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Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS, was synthesized by the reaction of ClF2CC(O)Cl with an excess of AgNCS. The colorless product melts at -85 C, and its vapor pressure follows the equation ln p = -4471.1 (1/T) + 11.35 (p [atm], T [K]) in the range -38 to 22 C. The compound has been characterized by IR (gas phase, Ar matrix, and matrix photochemistry), by liquid Raman, by 19F and 13C NMR, gas UV-vis, and photoelectron spectroscopy (PES), by photoionization mass spectrometry (PIMS), and by gas electron diffraction (GED). The conformational properties of ClF2CC(O)NCS have been analyzed by joint application of vibrational spectroscopy, GED and quantum chemical calculations. The existence of two conformers has been detected in the gas and liquid phases, in which the C-Cl bond adopts a gauche orientation with respect to the C=O group; the C=O group is in syn- or anti-position with respect to the N=C double bond of the NCS group. The computed ΔG difference between these two gauche-syn and gauche-anti forms is ΔG = 0.63 kcal mol-1 in the B3LYP/6-31G(d) approximation. The most significant gas-phase structural parameters for gauche-syn ClF2CC(O)NCS are re(NC=S) 1.559(2) A, re(N=CS) 1.213(2) A, re(N-C) 1.399(7) A, re(C=O) 1.199(2) A, and ∠e(CNC) 134.7(13). Photolysis of ClF2CC(O)NCS using an ArF excimer laser (193 nm) mainly yields ClF2CNCS, CO, and ClC(O)CF2NCS. The valence electronic properties of the title compound were studied using PES and PIMS. The experimental first vertical ionization energy of 10.43 eV corresponds to the ejection primarily of the sulfur lone-pair electrons of the in-plane nonbonding orbital on the NCS group.
- Ramos, Luis A.,Ulic, Sonia E.,Romano, Rosana M.,Vishnevskiy, Yury V.,Mitzel, Norbert W.,Beckers, Helmut,Willner, Helge,Tong, Shengrui,Ge, Maofa,Vedova, Carlos O. Della
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- Gas phase structures of trifluoroacetyl chloride, CF3C(O)Cl, and chlorodifluoroacetyl chloride, CF2ClC(O)Cl
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The geometric structures of trifluoroacetyl chloride, CF3C(O)Cl, and chlorodifluoroacetyl chloride, CF2ClC(O)Cl were determined by gas electron diffraction. The CF3 group in CF3C(O)Cl adopts an eclipsed orientation relative to the C=O double bond. In the predominant conformer of CF2ClC(O)Cl (93(3)%) the two chlorine atoms are gauche to each other (6(ClCCCl) = 75.4(10)°) with a small contribution of the trans form (Θ(ClCCCl) = 180°). The experimental geometric parameters are compared to those obtained by ab initio calculations.
- Gobbato, Karina I.,Leibold, Christiane,Centeno, Silvia,Vedova, Carlos O. Della,Mack, Hans-Georg,Oberhammer, Heinz
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- Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO: Preparation and structural and spectroscopic studies
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Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO, was prepared by the reaction of ClF2CC(O)Cl with excess of AgNCO. The colorless compound melts at -83 °C and the vapor pressure follows the equation ln p = -3868.3 (1/T) + 10.89 (p [Atm], T [K]) in the range -38 to +22 °C, extrapolated bp ca. 82 °C. It has been characterized by IR (gas phase, Ar matrix), liquid Raman, 19F and 13C NMR, gas UV-vis spectrum, photoelectron spectroscopy (PES), photoionization mass spectrometry (PIMS), and gas electron diffraction (GED). The matrix photochemistry has been studied and the conformational properties of ClF2CC(O)NCO have been analyzed by joint application of vibrational spectroscopy, GED, and quantum chemical calculations. Two conformers were detected in gaseous and liquid phases, in which the C-Cl bond adopts a gauche orientation with respect to the C=O group, whereas this group can be in syn or anti orientation with respect to the N=C bond of the NCO group. An enthalpy difference δHexp° = 1.3 ± 0.2 kcal mol-1 between the most stable syn-gauche and the less stable anti-gauche form was derived using the van't Hoff equation, which is in reasonable agreement with the computed difference of δH° = 0.8 kcal mol-1 (B3LYP/6-311+G(3df) approximation). The most significant gas phase structural parameters for gauche-syn ClF2CC(O)NCO are re(NC=O) = 1.157(1) A, re(N=CO) = 1.218(1) A, re(N-C) = 1.378(9) A, re(C=O) = 1.195(1) A,e(CNC) = 128.6(19)°. Photolysis of ClF 2CC(O)NCO using an ArF excimer laser (193 nm) mainly yield ClF 2CNCO along with some ClF2CC(O)N nitrene. The valence electronic properties of the title compound were studied using the PES and PIMS. The experimental first vertical ionization energy of 11.54 eV corresponds to the ejection of a carbonylic oxygen lone pair electron.
- Ramos, Luis A.,Ulic, Sonia E.,Romano, Rosana M.,Vishnevskiy, Yury V.,Berger, Raphael J. F.,Mitzel, Norbert W.,Beckers, Helmut,Willner, Helge,Tong, Shengrui,Ge, Maofa,Della Vedova, Carlos O.
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- Chlorodifluoroacetyl azide, ClF2CC(O)N3: Preparation, properties, and decomposition
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Chlorodifluoroacetyl azide, ClF2CC(O)N3, was prepared and characterized by IR (gas, Ar matrix), Raman (liquid), UV-vis (gas), and 19F, 13C NMR spectroscopy. The vibrational spectra were analyzed in terms of a single conformer, gauche-syn, where the Cl-C and the Nα=Nβ bonds are gauche and syn to the C=O bond, respectively. The photo and thermal decomposition reactions of the azide were studied with the aid of matrix isolation. In both cases, a new isocyanate species ClF2CNCO was produced and characterized by matrix IR spectroscopy. The conformational properties and the Curtius rearrangement pathways of this new carbonyl azide were theoretically explored, which suggest the preference of a concerted over stepwise decomposition for the global minimum gauche-syn conformer.
- Ramos, Luis A.,Zeng, Xiaoqing,Ulic, Sonia E.,Beckers, Helmut,Willner, Helge,Della Vedova, Carlos O.
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- Synthesis of 2-(Chlorodifluoromethyl)indoles for Nucleophilic Halogen Exchange with [18F]Fluoride
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The synthesis of 2-[18F]trifluoromethylated indoles from the corresponding chlorodifluoromethyl precursors was found to proceed under milder conditions when compared to known metal-free nucleophilic exchange reactions with [18F]fluoride on chlorodifluoro-methyl arenes. A key element in the reaction course is – most likely – a favorable elimination-addition mechanism on the 2-methyl position of the indole. Given the increasing interest in 18F-labelled compounds, this single step labeling methodology nicely complements the so far existing routes to 2-[18F]trifluoromethylated indoles.
- Bock, Leonard,Schulthei?, Stefanie K.,Maschauer, Simone,Lasch, Roman,Gradl, Susanne,Prante, Olaf,Zard, Samir Z.,Heinrich, Markus R.
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supporting information
p. 6258 - 6262
(2021/12/17)
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- Photooxidation preparation method of haloacetyl chloride
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The invention discloses a photooxidation preparation method of haloacetyl chloride. The halogenated alkane is mixed with an oxygen source and vaporized, and then the materials are introduced into a reactor for photooxidation to obtain haloacetyl chloride, the photooxidation reaction temperature is 5 to 60 DEG C, the stay time of the material is 1 to 50 s, and the molar ratio of the oxygen source to the halogenated alkane is 0.1 to 5:1, a quartz cold trap is arranged in the reactor, and the quartz cold trap is composed of a quartz inner shell and a quartz outer shell, a light source is arrangedin the quartz inner shell, and a double-layer cold trap jacket is formed between the quartz inner shell and the quartz outer shell, and the double-layer cold trap jacket is filled with circularly flowed filter liquid, and the filter liquid filters out ultraviolet light generated by the light source in a wavelength band of less than 300 nm. The method has the advantages of simple process, high yield, safety and environmental protection, and continuous operation.
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Paragraph 0021; 0024; 0042-0049
(2019/01/24)
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- DISTILLATION PROCESS COMPRISING AT LEAST TWO DISTILLATION STEPS TO OBTAIN PURIFIED HALOGENATED CARBOXYLIC ACID HALIDE, AND USE OF THE PURIFIED HALOGENATED CARBOXYLIC ACID HALIDE
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The present invention concerns a process for the production of a fluorinated carboxylic halide having a reduced content of impurities, a fraction of the fluorinated carboxylic halide having a reduced content of impurities, and its use in the manufacture of agriculturally and pharmaceutically active compounds or their intermediates.
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Page/Page column 9
(2016/06/15)
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- HALOGENATION PROCESS OF 1,1-DIHALOETHENE
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The present invention concerns a halogenation process, in which a 1,1- dihaloethene CX2=CH2 (I) with at least one halogenation agent. The invention concerns further a process for the manufacture of chlorodifluoroacetic acid chloride (CDFAC), which comprise the steps of (a) chlorination of VF2, and (b) an oxidation process. Another object of the present invention is a process for the manufacture of agriculturally or pharmaceutically active compounds, comprising the halogenation and/or oxidation process.
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Page/Page column 8
(2016/07/05)
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- Synthesis production process of difluorochloroacetic acid
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The invention discloses a synthesis production process of difluorochloroacetic acid, comprising the following steps: charging sulfur trioxide with nitrogen gas into an oxidation reaction kettle by an intermittent process, starting stirring; after reaching a certain temperature, adding difluorotetrachloroethane and catalyst according to a predetermined ratio into the oxidation reaction kettle; heating for reaction, observing the backflow condition, starting steaming the byproduct sulfuric chloride when the kettle temperature rises to a certain temperature while the backflow is small; after steaming the byproduct sulfuric chloride, carrying out charging for the second time; carrying out three-stage spray hydrolysis and absorption on the product difluorochloracetyl chloride to generate crude product difluorochloroacetic acid, and carrying out defluorination and rectification on the crude product to obtain finished product difluorochloroacetic acid. The synthesis production process of difluorochloroacetic acid disclosed by the invention adopts the difluorotetrachloroethane as a raw material, the finished product difluorochloroacetic acid is prepared by oxidation reaction, the preparation process has reasonable design, high absorption rate, high overall yield and low energy consumption; and the byproduct can be hydrolyzed and reused, so that the production process is clean, environment-friendly, safe and reliable.
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Paragraph 0015-0021
(2017/05/10)
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- A scalable and regioselective synthesis of 2-difluoromethyl pyridines from commodity chemicals
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A scalable de novo synthesis of difluoromethyl pyridines from inexpensive materials is reported. The pyridyl subunit is built around the difluoromethyl group rather than a late stage introduction of this moiety. This user-friendly approach allows access to a diverse range of substitution patterns on all positions on the ring system and on the difluoromethyl group.
- Desrosiers, Jean-Nicolas,Kelly, Christopher B.,Fandrick, Daniel R.,Nummy, Larry,Campbell, Scot J.,Wei, Xudong,Sarvestani, Max,Lee, Heewon,Sienkiewicz, Alexander,Sanyal, Sanjit,Zeng, Xingzhong,Grinberg, Nelu,Ma, Shengli,Song, Jinhua J.,Senanayake, Chris H.
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p. 1724 - 1727
(2014/04/17)
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- A practical source of chlorodifluoromethyl radicals. Convergent routes to gem -difluoroalkenes and -dienes and (2,2-Difluoroethyl)-indoles, -azaindoles, and -naphthols
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The preparation of O-octadecyl-S-chlorodifluoromethyl xanthate from chlorodifluoroacetic acid and its use as a convenient source of chlordifluoromethyl radicals is described. This reagent may be used to access gem-difluoroalkenes and -dienes, as well as (2,2-difluoroethyl)indolines, -indoles, and -naphthols.
- Salomon, Pierre,Zard, Samir Z.
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supporting information
p. 2926 - 2929
(2014/06/23)
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- An atom-efficient route to ethyl 3-(difluoromethyl)-1-methyl-1 H-pyrazole-4-carboxylate (DFMMP)-A key building block for a novel fungicide family
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A growing number of fluorine-containing active ingredients in the pharmaceutical and agrochemical industries inevitably raises the demand for new fluorinated building blocks. Their availability is mainly constricted by suitable chemistry and available bulk fluorine containing starting materials. Because of the high cost impact especially in the agrochemical industry, the choice of a synthetic route is heavily driven by economic aspects; thus, the environmental profile often is handled as a "secondary factor" or finally falls aside. DFMMP is a key building block for a fast growing new fungicide family, like Syngenta's Sedaxane, and BASF's Fluxapyroxad and Bayer's Bixafen currently made by environmetally less friendly routes. Herein we present a cost-competitive and green route, developed at Solvay laboratories, displaying significantly lower environmental impact.
- Jaunzems, Janis,Braun, Max
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p. 1055 - 1059
(2014/10/15)
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- PROCESS FOR THE PREPARATION OF ESTERS OF 4-FLUOROSUBSTITUTED 3-OXO-ALCANOIC ACIDS
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Esters of 4-fluorosubstituted 3-oxo-alcanoic acids can be prepared by addition reaction of ketene with the respective acid chloride, subsequent esterification and hydrodechlorination. Preferred reaction products are esters of 4,4- difluoro-3-oxo-butanoic acid.
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Page/Page column 4
(2009/04/25)
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- Ethyl difluoro(trimethylsilyl)acetate and difluoro(trimethylsilyl) acetamides - Precursors of 3,3-difluoroazetidinones
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Difluoro(trimethylsilyl)acetamides 7 have been prepared from chlorodifluoroacetamides 5 by electrochemical silylation. When condensed with carbonyl compounds, they were shown to be precursors of 2,2-difluoro-3- hydroxyacetamides 8. N-(p-Methoxyphenyl)-2,2-difluoro-3-hydroxy-4- methylvaleramide (8a) has been converted into the correspending 3,3-difluoroazetidinone 9a. This new route to 3,3-difluoroazetidinones is shown to be an alternative to the one utilizing the condensation of ethyl difluoro(trimethylsilyl)acetate with imines. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Bordeau, Michel,Frebault, Frederic,Gobet, Mallory,Picard, Jean-Paul
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p. 4147 - 4154
(2007/10/03)
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- Kinetics of the gas-phase reaction of Cl atoms with CF2ClCFClH at 263-313 K
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The kinetics of the reaction of Cl atoms with CF2ClCFClH at 263-313 K were studied. The decay of CF2ClCfClH and the reference compounds was measured using infrared absorption in the 700-2000 cm-1. Three reference compounds were used: CF2ClH, CH3CN and CH4. Cl atom initiated oxidation of CF2ClCFClH generated a product with a carbonyl stretching which increased linearly with lost of CF2ClCFClH. The substitution of Cl by F atoms results in a strengthening of C-H bonds and hence a lowering of reactivity towards Cl atoms. The closer proximity and increased inductive effect of the F atom decreases the reactivity of HCFC-123a.
- Mauer,Wallington,Barnes,Becker
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p. 785 - 788
(2007/10/03)
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- Process for preparing polyfluorochlorocarbonyl chlorides and perfluorocarbonyl chlorides with addition of chlorine
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A process for preparing polyfluorochloro- and perfluorocarbonyl chlorides, for example for preparing perfluoropropionyl chloride, chlorodifluoroacetyl chloride or trifluoroacetyl chloride, in which starting materials are employed which have a CHCl2 group which is converted to a C(O)Cl group by photochemical oxidation with oxygen in the presence of added elemental chlorine and under exposure to activating irradiation by light having a wavelength λ≥290 nm. The procedure is preferably unpressurized. Outstanding conversions with high selectivity are achieved using doped Hg light sources.
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- Cyclization of α,α-difluoromethyl radicals: A new route to the preparation of difluorocyclopentane derivatives
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Intramolecular cyclization of difluoromethyl radicals with olefins, silylacetylenes and enol acetates afforded a variety of substituted difluorocyclopentanes.
- Barth, Francis,O-Yang, Counde
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p. 5873 - 5876
(2007/10/02)
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- The Thermal Gas-Phase Reaction of NO2 with 1,1-Dichlorodifluoroethane, CF2CCl2 in the Presence of O2
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The gas-phase reaction of NO2 with CF3CCl2 in the presence of O2 has been studied at 257.3 and 300.2 K./ The initial pressure of NO2 was varied between 0.7 and 4.7 torr, that of CF3CCl2 between 18.4 and 81.9 torr and that of O2 between 50.4 and 696.3 torr.Several experiments were made in the presence of N2 varying its pressure between 135 and 394 torr.Seven products were formed: COF2, COCl2, CF2ClC(O)Cl, , O2NCF2C(O)Cl, CF2ClCCl2NO2 and CF2ClCCL2O2NO2.The reaction was a homogeneous chain reaction, whose rate and distribution of the products depended on the relation between NO2, CF2CCl2 and O2 and also on the total presure.The following mechanism, where E = CF2CCl2, R' = O2NCF2CCl2, R'' = CF2C;CCl2, R = R' or R'' and M = effective pressure, explains the experimental results 1.) NO2 + E = R', 2.) R' + O2 + M = R'O2 + M 3.) 2 R'O2 = 2 R'O + O2, 4.) R'O = O2NCF2C(O)Cl + Cl, 5.) Cl + E = R'' 6.) R'' + NO2 + M = R''NO2 + M, 7.) R'' + O2 + M = R''O2 + M, 8.) R''O2 + NO2 + M = R''O2NO2 + M, 9.) R''O2NO2 = R''O2 + NO2, 10.) 2 R''O2 = 2 R''O + O2, 11.) R''O = CF2ClC(O)Cl + Cl, 12.) RO2 + E = RO2(E), 13.) RO2(E) = RO + ,14.) RO2(E) + O2 + M = RO2(E)O2 + M, 15.) 2 RO2(E)O2 = 2 RO2(E)O + O2, 16.) RO2(E)O = RO + COF2 + CLCl2. At room temperature the value of 1.3 +/- 0.2*10-4 S-1 was obtained for K9.
- Czarnowski, Joanna
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- THE 1,2-FLUORINE ATOM MIGRATION IN THE EPOXIDE OF 1,1-DICHLORODIFLUOROETHENE. THE INFRARED SPECTRUM OF DICHLOROFLUOROACETYL FLUORIDE
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The epoxide of 1,1-dichlorodifluoroethene, , and chlorodifluoroacetyl chloride, CF2ClC(O)Cl, were the principle products of the gas-phase thermal reaction of NO2 with 1,1-dichlorodifluoroethene, CF2CCl2, in presence of O2 at 257.3 K and 300.2 deg K.Five other products: COF2, COCl2, O2NCF2C(O)Cl, CF2ClCCl2NO2 and CF2ClCCl2O2NO2 were also formed in minor amounts of traces, depending on the relation between NO2, CF2Cl2 and O2.The initial pressure of NO2 was varied between 0.7 and 4.7 torr, that of CF2CCl2 between 18.4 and 81.9 torr, and that of O2 between 50.4and 696.3 torr.The isomerisation of to CF2ClC(O)Cl was never observed, but, in the presence of mercury vapour, the rearrangement of to CFCl2C(O)F occured, involving the unexpected 1,2-migration of a fluorine atom.The infrared spectrum of CFCl2C(O)F is given.The elementary reactions sequence is proposed to explain the formation of CF2C(O)Cl and .
- Czarnowski, Joanna
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p. 193 - 198
(2007/10/02)
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- Kinetics and Mechanism of the Thermal Reaction between Trifluoromethylhypofluorite and 1,1-Dichlorodifluoroethylene
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The thermal addition of CF3OF to CF2CCl2 has been studied between -7.0 and 29.7 deg C.The pressure of CF3OF was varied between 6.4 and 196.7 Torr and that of CF2CCl2 between 5.4 and 203 Torr.CF3CCl2F, CF3O(CF2CCl2)F and CF3O(CF2CCl2)iOCF3, where i = 2,3. . .n, were the products.Above 110 Torr of olefin, non-volatile condensate appeared.The reaction was homogeneous and not affected by the total pressure or the presence of an inert gas.Introducing a few Torr of O2 to the reaction system an instantaneous oxidation of CF2CCl2 to CF2ClC(O)Cl occurred.Higher amounts of O2 led to explosion with conversion of both reactant molecules.The basic steps of the reaction were: generation of radicals CF3O. and CF3CCl2. in the bimolecular process between CF3OF and CF2CCl2 (rate constant k1), generation of telomeric radicals by addition of CF3O. to CF2CCl2, abstraction of fluorine atoms from CF3OF by CF3CCl2. and by CF3O(CF2CCl2). (rate constant k4), chain propagation by further successive addition of telomeric radicals to another molecule of olefin (k5) and recombination of telomeric radicals.The following values of the rate constants were obtained: k1 = (5.0+/-1.0)106exp(-9.7+/-0.9 kcal*mol-1/RT)l*mol-1s-1, k4 = (2.6+/-0.5)107exp(-3.1+/-0.6 kcal*mol-1/RT)l*mol-1s-1, k5 = (1.7+/-0.4)105exp(-2.5+/-0.5 kcal*mol-1/RT)l*mol-1s-1. - Keywords: CF3OF, thermal reaction with CCl2CF2 / CCl2CF2, thermal reaction with CF3OF / Trifluoromethylhypofluorite, addition to 1,1-dichlorodifluoroethylene / 1,1-Dichlorodifluoroethylene, reaction with trifluoromethylhypofluorite
- Santos Afonso, M. dos,Czarnowski, J.
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- REGIOSPECIFIC PREPARATION OF α,α-DIHALOFLUOROMETHYL PERFLUOROALKYL KETONES.
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Acylation of F-phosphoranium salts with F-acyl chlorides gives the corresponding Z-perfluoro betaine in high yield.Subsequent chlorination or bromination regiospecifically yields the α,α-dihalofluoromethyl perfluoroalkyl ketones.
- Jeong, In Howa,Burton, Donald J.,Cox, Daryl G.
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p. 3709 - 3712
(2007/10/02)
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