cas 75-72-9, Chlorotrifluoromethane | Articles data

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EXPLOSIVE REACTIONS OF LIQUID MIXTURES OF CHLORINE TRIFLUORIDE WITH HYDROCARBONS AND HALOCARBONS
Combinations of liquid ClF3 with several hydrocarbons and halocarbons have been caused to explode by sudden mixing at various temperatures from 25 degC downward.The mixtures occasionally detonate.By fast recording of pressure, flame ionization, and carbon deposition it is found that mixtures derived from all of the fuels tested except perfluorohexane initiate in less than 1 ms at all temperatures down -70 degC.An ionic mechanism is proposed.Analysis of the explosion gases indicates that all chemical bonds including C-H are labilized owing to the extremely high temperature.Calorimetric measurements agree with calculated heats of explosion.
Brower, K. R.
p. 333 - 350
(1986)
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Heterogeneous catalyzed decomposition reactions of dichlorodifluoromethane in the presence of water on γ-alumina
The heterogeneous catalyzed decomposition of CCl2F2 (CFC-12) in the presence of water was investigated, employing γ-alumina as catalyst. The catalyzed hydrolysis reaction yields very high conversion degrees of CFC-12 in the first reaction stage. For a period of about 3 h there is a remarkable lack of balance between the amount of liberated HF and HCl owing to the uptake of HF by the oxide solid forming α-AlF3. Only after about 3 h does the heterogeneous solid/gas reaction come to an end and then the HCl and the HF balance is equal. With the increasing fluoride content of the solid phase, the decomposition degree of CFC-12 decreases to a stable value of about 60% with respect to liberated CO2. The conversion degree of CFC-12 seems to be higher but this is owing to the formation of CClF3 (CFC-13), which is nearly stable under the conditions used. Mechanistic explanations are given for the formation of CClF3 whether by dismutation reactions or owing to hydrofluorination reactions of CFC-12. Arguments are given about which mechanism might be the most probable. Furthermore, mechanistic hypotheses are concluded and discussed with respect to the processes at the catalyst surface on the basis of the experimental results.
Kemnitz,Kohne,Lieske
p. 197 - 204
(1997)
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PROCESSES FOR PRODUCING TRIFLUOROIODOMETHANE
The present disclosure provides a gas-phase process for producing trifluoroiodomethane, the process comprising providing a reactant stream comprising hydrogen iodide and trifluoroacetyl halide selected from the group consisting of trifluoroacetyl chloride, trifluoroacetyl fluoride, trifluoroacetyl bromide, and combinations thereof, and reacting the reactant stream in the presence of a catalyst at a temperature from about 200° C. to about 600° C. to produce a product stream comprising the trifluoroiodomethane.
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Paragraph 0053-0055

(2020/03/09)

Cu-catalyzed chlorotrifluoromethylation of alkenes with CF3SO2Cl
Although CF3SO2Cl is an efficient chlorotrifluoromethylation reagent, an expensive transition metal complex usually has to be used. We found that CuCl2-catalyzed chlorotrifluoromethylation of alkenes with CF3SO2Cl occurred smoothly under mild conditions. A wide substrate scope and good functional group compatibility were observed.
Zhang, Wei,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information
p. 25 - 31
(2018/09/18)

One-Step Process for Hexafluoro-2-Butene
Disclosed is a one step process for making of 1,1,1,4,4,4-hexafluoro-2-butene. More specifically, the present invention provides a process for making hexafluoro-2-butene, continuously, from 2-chloro-3,3,3-trifluoropronene using Fe2O3/NiO impregnated carbon catalyst at 600° to 650° C.
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Paragraph 0033; 0034

(2016/02/18)

PROCESS FOR 1-CHLORO-3,3,3-TRIFLUOROPROPENE FROM TRIFLUOROMETHANE
The present invention provides routes for making 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) from commercially available raw materials. More specifically, this invention provides routes for HCFO-1233zd from inexpensive and commercially available trifluoromethane (HFC-23).
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Paragraph 0056; 0057

(2015/02/25)

Chemical ionization using CF3+: Efficient detection of small alkanes and fluorocarbons
The trifluoromethyl ion CF3+ is evaluated as a chemical ionization (CI) precursor in a compact Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer. It reacts with alkanes by hydride abstraction allowing characterization and quantification of alkanes up to C4 and cyclic. With larger alkanes fragmentation occurs. Fluorocarbons react by fluoride abstraction. Rate coefficients have been measured for reaction with alkanes, fluoroalkanes, chlorofluoroalkanes as well as several common VOCs. Use of CF3+ for trace analysis in air has been tested on an air sample containing traces of acetone, toluene, benzene and cyclohexane. The results are consistent with those obtained with H3O+ precursor and allow additional cyclohexane quantification.
Dehon, Christophe,Lemaire, Jo?l,Heninger, Michel,Chaput, Aurélie,Mestdagh, Hélène
experimental part
p. 113 - 119
(2011/08/21)

Nitrogen trifluoride as an oxidative co-reagent in high temperature vapor phase hydrofluorinations
Nitrogen trifluoride (NF3) has proven to be a useful additive in high temperature vapor phase hydrofluorination reactions of chlorocarbons. The activity of chromium-based catalysts is maintained by introducing a co-stream of NF3 into the reagent chlorocarbon and HF stream. NF3 is a desirable additive instead of O2 as there is no water generation due to its use.
Belter, Randolph K.,Sweval, Mark S.,Iikubo, Yuichi
p. 816 - 820
(2008/03/27)

Methane and methyl chloride as selective reducing agent in the transformation of hydrochlorofluorocarbons or chlorofluorocarbons to hydrofluorocarbons
A gas phase reaction process for producing a hydrofluorocarbon from a hydrochlorofluorocarbon or chlorofluorocarbon reactant by contacting, in the presence of a catalyst, the hydrochlorofluorocarbon or chlorofluorocarbon reactant with a reducing agent selected from methane, methyl chloride and mixtures thereof, to produce the hydrofluorocarbon.
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Page/Page column 6

(2008/06/13)

Method for the preparation of high surface area metal fluorides
The present invention is related to a method for preparing an amorphous metal fluoride of the formula MX+FX-δ comprising the steps of a) providing a precursor, whereby the precursor comprises a structure having a formula of Mx+F(x-δ)-yBy; and b) reacting the precursor with a fluorinating agent generating the amorphous metal flouride having a formula of Mx+Fx-δ, whereby M is selected from the group comprising metals of the second, third and fourth main group and any subgroup of the periodic table, B is a coordinately bound group; x is any integer of 2 or 3; y is any integer between 1 and 3; δ is 0 to 0.1; and x?δ>y.
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Page/Page column 8

(2010/10/20)

Materials and methods for the conversion of hydrofluorocarbons
Methods and materials are disclosed for the recovery of valuable hydrofluorocarbons and subsequent conversion to environmentally inert compounds. More specifically methods and materials are provided for recovering hydrofluorocarbons such as HFC-227, HFC-236, HFC-245, HFC-125, HFC-134, HFC-143, HFC-152, HFC-32, HFC-23 and their respective isomers. Processes are provided for converting hydrofluorocarbons such as these to fluoromonomer precursors such as CFC-217, CFC-216, CFC-215, CFC-115, CFC-114, CFC-113, CFC-112, HCFC-22, CFC-12, CFC-13 and their respective isomers. Materials, methods and schemes are provided for the conversion of these fluoromonomer precursors to fluoromonomers such as HFP, PFP, TFP, TFE, and VDF.
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Page 9

(2008/06/13)

A selected ion flow tube study of the reactions of gas-phase cations with PSCl3
A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl3. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with 19 cations; H3O+, CF3+, CF +, NO+, NO2+, SF2 +, SF+, CF2+, O2 +, H2O+, N2O+, O +, CO2+, CO+, N+, N 2+, Ar+, F+ and Ne+ (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl3 from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions; the agreement is particularly good for the atomic ions Ar+, F+ and Ne+. Some reactions (e.g. O2++PSCl3), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. H3O+, CF 3+, CF+ and NO+), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl3.
Critchley, Andrew D.J.,Howle, Chris R.,Mayhew, Chris A.,Tuckett, Richard P.
p. 235 - 241
(2008/10/09)

The radiation chemistry of acyclic hydrofluoro and perhalogenated ether and hydrocarbon compounds
The radiolytic stability of some hydrofluoroethers and hydrofluorocarbons was investigated and compared with those of perfluoropolyethers (PFPEs) and the CCl2FCClF2 (CFC 113). The experimental results indicate that stability depends mainly on the relative abundance of hydrogen atoms in the molecule; however, a significant role is played also by the chemical structure (i.e. the relative positions of the hydrogen atoms in the molecule). As a result, molecules containing hydrogen atoms as -OCF2H chain ends show a higher stability compared with the other hydrofluoro compounds. Based on the analysis of the end products and on the nature of radicals detected by EPR, radiolysis mechanisms are proposed and discussed. Due to their high dipole moments the hydrofluoro compounds and CCl2FCClF2 degrade mainly through an ionic mechanism.
Marchionni, Giuseppe,Guarda,Buttafava,Faucitano, Antonio
p. 153 - 162
(2007/10/03)

A kinetic and mechanistic study of the Cl/F exchange reaction of CCl3F, CCl2F2, and CClF3 with prefluorided chromia
A kinetic and mechanistic study of the Cl/F exchange reaction of CCl3F, CCl2F2, and CClF3 with prefluorided chromia was conducted. The activation energies of 53 and 54 kJ/mol for the simultaneous mono- and bi-exchange of the chlorine atoms of CCl3F with the surface fluoride ions of a prefluorided chromia were lower than that found for CCl4 (65 kJ/mol). This was due to the stronger C-F bond formed in CCl2F2 and CClF3, the C-Cl bond strengths in CCl4 and CCl3F were roughly the same. Mono-exchange occurred through a four-center intermediate in which the breaking of a C-Cl bond is compensated for by the formation of a C-F bond. Bi-exchange occurred by the CCl3F adsorption by the bonding of two Cl atoms to two appropriately spaced Cr ions on the CrF surface. Mono-exchange only was observed in the reaction of CCl2F2, the activation energy for which was 84 kJ/mol. This higher activation energy was due to the higher C-Cl (～ 318 kJ/mol) bond strength in CCl2F2 than in CCl3F (D(C-Cl) = 305 kJ/mol). The absence of the occurrence of bi-exchange producing CF4 was due to the instantaneous formation of CClF3 on the intermediate, which was adsorbed through two chlorine atom where bi-exchange should have been possible. No exchange of the C-Cl bond of CClF3 with the surface CrF was observed.
Waugh,Farrokhnia,Sakakini
p. 9567 - 9575
(2007/10/03)

Atmospheric degradation mechanism of CF3OCF2H
Smog chamber/FTIR techniques were used to study the Cl atom initiated oxidation of CF3OCF2H in 700 Torr of N2/O2 at 295±2K. Atmospheric oxidation of CF3OCF2H proceeds via the formation of C
Inoue,Kawasaki,Wallington,Hurley
p. 296 - 302
(2007/10/03)

Magnesium fluoride as a catalytic support in hydrodechlorination of CCl2F2 (CFC-12)
Magnesium fluoride-supported palladium and ruthenium appear to be useful catalysts in the reaction of CCl2F2 (CFC-12) hydrodechlorination; after doping Pd/MgF2 with gold the selectivity for CH2F2 increased from ~ 70 to almost 90%.
Malinowski,Juszczyk,Pielaszek,Bonarowska,Wojciechowska,Karpinski
p. 685 - 686
(2007/10/03)

Decomposition of chlorofluorocarbons over metal phosphate catalysts part I. Decomposition of CCI2F2 over metal phosphate catalysts
In the decomposition of chlorofluorocarbons (CFCs), HF produced in the decomposition reacts with and deactivates the catalyst. Metal phosphates were chosen as the catalyst from ΔG calculations. Zr-P-O and AlPO4 showed high catalytic activity for the decomposition of CCl2F2 above 350°C. The essential reaction of the decomposition is hydrolysis. On increasing the CCl2F2 concentration in the feed, the formation of CClF3 as a by-product is promoted. ALPO4 has both weak acid sites and those of intermediate strength and these acid sites may participate in the hydrolysis of CCl2F2. No reaction between AlPO4 and formed HF was observed during 1000 h reaction at 400°C, ALPO4 promises to be of practical use.
Takita, Yusaku,Ninomiya, Maiko,Matsuzaki, Rie,Wakamatsu, Hironori,Nishiguchi, Hiroyasu,Ishihara, Tatsumi
p. 2367 - 2372
(2007/10/03)

Generation of radical species in surface reactions of chlorohydrocarbons and chlorocarbons with fluorinated gallium(III) oxide or indium(III) oxide
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.
Thomson
p. 1881 - 1885
(2007/10/03)

Chlorine Abstraction Reaction from Chloroprentafluorobenzene by the CF3 Radical
The temperature dependence of the rate constant for the gas phase abstraction reaction of chlorine by CFj from chloropentafluorobenzene was determined in the temperature range 573-653 K by the competitive method using the recombination of CF3 radicals as reference reaction. Taking a value of 1.53-1013 cm3 mor1 s-1 for the recombination rate constant, kc, = (6.76± 1.26) 1012 exp [-(6339±103) K/7] cm3 mor1 s-1. The Arrhcnius parameters were calculated by the Bond Strength-Bond Length method (BSBL) and good agreement was obtained with the experimental values. WILEY-VCH Verlag GmbH, 1998.
Nieto,Herrera,Lane,Oexler
p. 821 - 825
(2007/10/03)

Photolysis of matrix-isolated CF3C(O)SH and CF3C(O)SCl
Perfluoroacetylthiol, CF3C(O)SH, and perfluoroacetylsulphenyl chloride, CF3C(O)SCl, were irradiated in an inert gas matrix to produce CF3SH and CO, and CF3SCl, CF3Cl, CO and SCO, respectively. The compounds are identified by evaluating the apparition of new bands in the FTIR spectrum of the matrix-isolated substance. The results are compared with related studies of similar compounds taking into account both the irradiation and the stability of the formed products.
Ulic,Gobbato,Della Vedova
p. 171 - 175
(2007/10/03)

Stable and active AlPO4 catalyst for decomposition of CCl2F2
CCl2F2 was decomposed to CO2 at 350-450 °C in the presence of water vapor and O2 over AlPO4 calcined at 1000 °C. CCl2F2 conversion slightly decreased at initial 50 h and then took a steady value. AlPO4 was not fluorinated during 1000 h reaction at 400 °C.
Takita, Yusaku,Li, Gong-Liang,Matsuzaki, Rie,Wakamatsu, Hironori,Nishiguchi, Hiroyasu,Moro-Oka, Yoshihiko,Ishihara, Tatsumi
p. 13 - 14
(2007/10/03)

On the mechanism of the reaction of CF3 radicals with C6F5Cl in the temperature range 318-473 K
The gas-phase reaction of CF3 radicals, generated by photolysis of perfluoroacetic anhydride, with C6F5Cl was studied in the temperature range 318-473 K and total pressures between 23 and 41 Torr. CF3 radicals react with C6F5Cl according to the following mechanism: CF3 + C6F5Cl ?kadd CF3C6F5Cl (1), (-1) CF3 + CF3C6F5Cl → CF3Cl + C6F5CF3 (2) 2CF3 →kc C2F6 (3) It was found that the addition reaction becomes reversible above 390 K. The addition rate parameters can be summarized in the following equation: log [(kadd/kc1/2)mol-1/2cm 3/2s-1/2] = (4.46±0.10)-(22.48±0.70)/θ where θ = 2.303 RTkJ mol-1 and kc is the recombination constant of CF3 radicals. A correlation between log(kadd/kc1/2) and the ionization potentials for 15 aromatic compounds was found. VCH Verlagsgesellschaft mbH, 1997.
Nieto,Lane,Oexler
p. 868 - 871
(2007/10/03)

Interconversion of Chlorofluorocarbons in Plasmas
Chlorofluorocarbons undergo interconversion during destruction in an argon arc plasma, so that, for example, in the exhaust gas from destruction of CCl2F2, CClF3 is found to be the major residual ozone depleting substance: as electron capture detectors are 104 times less sensitive for CClF3, compared with CCl2F2, although these gases have the same ozone depleting potential, analysis of exhaust from destruction of chlorofluorocarbons is therefore not a trivial matter of determining only the level of input chlorofluorocarbon remaining.
Deam, Rowan T.,Dayal, Austin R.,McAllister, Trevor,Mundy, Alan E.,Western, Robert J.,et al.
p. 347 - 348
(2007/10/02)

Dismutation of CFC-12 to CFC-13 over Chromia-Alumina Catalyst
Selective transformation of CCl2F2 (CFC-12) to fluorine-rich CClF3 (CFC-13) in the absence of HF over a chromia-alumina catalyst has been achieved.
Venugopal, A.,Rao, K. S. Rama,Prased, P. S. Sai,Rao, P. Kanta
p. 2377 - 2378
(2007/10/03)

Kinetic Study of the Reaction of Chlorine Atoms with CF3I and the Reactions of CF3 Radicals with O2, Cl2 and NO at 296 K
The kinetics of the gas-phase reaction of Cl atoms with CF3I have been studied relative to the reaction of Cl atoms with CH4 over the temperature range 271 - 363 K.Using k(Cl + CH4) = 9.6*10-12 exp(-2680/RT) cm3 molecule-1 s-1, we derive k(Cl + CF3I) = 6.25*10-11 exp(-2970/RT) in which Ea has units of cal mol-1.CF3 radicals are produced from the reaction of Cl with CF3I in a yield which was indistinguishable from 100percent.Other relative rate constant ratios measured at 296 K during these experiments were k(Cl + C2F5I)/k(Cl + CF3I) = 11.0 +/- 0.6 and k(Cl + C2F5I) /k(Cl + C2H5Cl) = 0.49 +/- 0.02.The reaction of CF3 radicals with Cl2 was studied relative to that with O2 at pressures from 4 to 700 torr of N2 diluent.By using the published absolute rate constants for k(CF3 + O2) at 1-10 torr to calibrate the pressure dependence of these relative rate constants, values of the low- and high-pressure limiting rate constants have been determined at 296 K using a Troe expression: k0(CF3 + O2) = (4.8 +/- 1.2)*10-29 cm6 molecule-2 s-1; kinfinite(CF3 + O2) = (3.95 +/- 0.25)*10-12 cm3 molecule-1 s-1; Fc = 0.46.The value of the rate constant k(CF3 + Cl2) was determined to be (3.5 +/- 0.4)*10-14 cm3 molecule-1 s-1 at 296 K.The reaction of Cl atoms with CF3I is a convenient way to prepared CF3 radicals for laboratory study.
Kaiser, E. W.,Wallington, T. J.,Hurley, M. D.
p. 205 - 218
(2007/10/02)

Photolysis of matrix-isolated perfluoroacetyl chloride, CF3C(O)Cl
Perfluoroacetyl chloride is decomposed in an argon matrix to produce CF3Cl and CO.The compounds are identified when the bands of the initial IR spectra disappear with the concomitant appearance of signals at 1207, 1098, 782 and 562 cm-1, and the band 2137 cm-1 belonging to the CO stretching vibration of the CO molecule.This result is compared with related studies of similar compounds.
Vedova, C. O. Della,Rubio, R. E.
p. 279 - 282
(2007/10/02)

Process for preparing fluorinated compound
A fluorinated compound of the formula: in which R is a perfluoroalkyl group, a perchloroalkyl group, a polyfluoroalkyl group, a polychloroalkyl group or a polychloropolyfluoroalkyl group, each having at least one carbon atom is prepared at a high selectivity and a high yield by reacting tetrafluoroethylene with a compound of the formula: in which R is the same as defined above in the presence of a Lewis acid.
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(2008/06/13)

Room-temperature Catalytic Fluorination of C1 and C2 Chlorocarbons and Chlorohydrocarbons on Fluorinated Fe3O4 and Co3O4
A study of the room-temperature reactions of a series of C1 and C2 chlorohydrocarbon and chlorocarbon substrate molecules with fluorinated iron(II,III) oxide and cobalt(II,III) oxide has been conducted.The results show that fluorinated iron(II,III) oxide exhibits an ability to incorporate fluorine into the following substrates in the order: Cl2C=CCl2 > H2C=CCl2 > CH3CCl3 > CHCl3 > CH2Cl2 > CH2ClCCl3 > CCl4 > CHCl2CHCl2.The fluorinated cobalt(II,III) oxide gave the reactivity series CHCl3 > CCl4 > H2C=CCl2 > CHCl2CHCl2 > CH2Cl2 > CH3CCl3 > CCl2CCl2 > CH2ClCl3.Reactions of C1 chlorohydrocarbon or chlorocarbon probe molecules with fluorinated Fe3O4 gave predominately C1 chlorofluorohydrocarbon and chlorofluorocarbon products, respectively, whereas fluorinated cobalt(II,III) oxide produced predominately C2 chlorofluorohydrocarbon and chlorofluorocarbons.For fluorinated Co3O4 the distribution of C2 products obtained from C1 chlorohydrocarbon precursor molecules is consistent with the formation of radical intermediates at strong Lewis acid surfaces.C2 chlorohydrocarbons exhibit a fluorine for chlorine (F-for-Cl) exchange reaction through the catalytic dehydrochlorination of the substrate to the alkenic intermediate.The F-for-Cl exchange process was dependent upon the ability of the substrate material to undergo dehydrochlorination; the inability of a substrate to undergo dehydrochlorination results in the fluorination process proceeding through the formation of chlorocarbon or chlorohydrocarbon radical intermediates.
Thomson, James
p. 3585 - 3590
(2007/10/02)

Synthesis of functionalized polyfluoroalkyl hypochlorites and fluoroxy compounds and their reactions with some fluoroalkenes
Several new polyfluoroalkyl hypochlorites and fluoroxy compounds containing Cl, H and Br in the alkyl group have been prepared and characterized by 19F NMR, 1H NMR and IR spectroscopies and by their reactions with fluoroalkenes to produce new polyfluoroethers.The novel compounds are prepared by the CsF-catalyzed addition of F2 or ClF to the C=O bond in CF3C(O)CF2Cl, ClCF2C(O)CF2Cl, and their derivatives HCF2C(O)CF3 and HCF2C(O)CF2Cl.Compounds containing an α-CF3 group exhibit enhanced thermal stability.New fluoroxy compounds and hypochlorites have also been prepared from the acid fluorides CF3-CFX-C(O)F (X = Cl, Br), which are obtained by the ring-opening reaction of hexafluoropropene oxide with (CH3)3SiCl, LiBr and (C2H5)3SiBr.These -OX compounds behave similarly to previously known materials with two α-F atoms, decomposing quickly at room temperature to COF2 and haloalkanes.
Randolph, Bruce B.,DesMarteau, Darryl D.
p. 129 - 150
(2007/10/02)

Evaluation of the kinetic parameters for the reaction of trifluoromethyl radicals with CH3Cl in the gas phase in temperature range from 416 to 63 K
The hydrogen and chlorine atom abstraction reactions from CH3Cl by CF3 radicals produced by the photolysis of hexafluoroacetone (HFA) and CF3I were studied relative to the recombination of CF3 radicals:
Taccone,Olleta,Salinovich
p. 353 - 362
(2007/10/03)

Kinetics and Mechanisms of the CO2 Laser Induced Decompositions of CFCl3 and CF2Cl2
The kinetics and reaction mechanisms of the decomposition of CFCl3 and CF2Cl2 induced by a continuous CO2 laser are examined and compared with previous results for CF3Cl.All three compounds exhibit two temperature regimes, with similar reaction mechanisms in the low-temperature regimes and significantly different mechanisms in the high-temperature regimes.
Zitter, R. N.,Koster, D. F.,Choudhury, T. K.,Cantoni, A.
p. 2374 - 2377
(2007/10/02)

INFRARED LASER INDUCED DECOMPOSITION OF HEXAFLUOROBENZENE AND SOME MONOSUBSTITUTED DERIVATIVES. INTERMEDIACY OF THE PENTAFLUOROPHENYL RADICAL.
The infrared multiphoton laser induced reactions of hexafluorobenzene and related pentafluoro analogues (pentafluorobenzene, pentafluorochlorobenzene, pentafluorobromobenzene, and pentafluoroiodobenzene) have been investigated using a CO2 TEA laser.The study was carried out in order to define the decomposition products and to attempt to clarify their mode of formation.Thus, the products (relative yield, percent) of the irradiation of C6F6 (1027.3 cm-1; 0.73 J/cm2; 10 pulses; 25percent decomposition) were C2F4(64), C6F5CF3(28), C2F6(7), CF4(1) and that for C6F5H (949.4 cm-1; 0.80 J/cm2; 10 pulses; 25percent decomposition) was C2F4 and C6F5CF3.Increasing the number of pulses in the reaction with C6F6 decreased the amount of C2F4 and increased the amount of C6F5CF3 and C2F6 indicating secundary and tertiary reactions.Addition of halogen (X2, X = Cl, Br) to these reactions caused different products to be formed.Thus, the irradiation of a C6F6/Cl2 mixture (7.4/7 Torr; 1027.3 cm-1; 0.7 J/cm2; 35 pulses; 35percent reaction) afforded C6F5Cl(46); CF3Cl(24) and CF2Cl2(30).Irradiation of C6F5H/X2 mixtures afforded mainly C6F5X + HX.For example C6F5H/Br2 (10/40 Torr; 949.4 cm-1; 0.93 J/cm2; 10 pulses; 10percent reaction) gave C6F5Br and HBr exclusively.Irradiation of C6F5-X (X = Cl, Br, I) (977.2 cm-1; ca. 0.74 J/cm2; 200 pulses; 39-74percent reaction) gave C6F6 and a minor amount of decafluorobiphenyl , a radical combination product of the pentafluorophenyl radical (C6F5.).Increasing the fluence in these reactions gave similar products in most cases but in some instances increased the amount of C2F4 formed.The reactions and product distribution of the hydrogen substituted derivative (C6F5H) was examined in the presence of Br2 as a function of laser fluence and halogen concentration.It was found that the threshold for C6F5H decomposition was higher for the reaction involving Br2 (as compared with the reaction involving Cl2 or neat C6F5H).The presence of Br2 also decreased the amount of C6F5H that was decomposed, indicating a quenching process.The decomposition path with the lowest activation energie for these molecules is thought to be C6F5X -> C6F5. + X. and was accessible using a laser pulse with a fluence as low as 0.7 J/cm2.Using a higher laser fluence (ca. 1.2 J/cm2) di- and triatomic radicals were defined by spectroscopic identification of the and :CF2 species.These reactions are discussed in light of the formation of the C6F5. radical during a primary, laser induced, process.Subsequent decomposition to smaller fragments, combination with other radicals or scavenging by added reagents also takes place depending on the reaction conditions.
Watanabe, Akio,Koga, Yoshinori,Sugawara, Ko-ichi,Takeo, Harutoshi,Fukuda, Kenzo,Matsumura, Chi
p. 463 - 469
(2007/10/02)

ELECTROCHEMICAL SYNTHESIS OF PERFLUOROALKYLCHLORIDES
Electrooxidation of perfluorocarboxylic acids in the presence of Cl2 yields perfluoroalkylchlorides RFCl.It is suggested that anodic oxidation of perfluorocarboxylate ions is the determining electrochemical stage in this electrochemical version of the Borodin-Hundsdikker reaction.
Grinberg, V. A.,Cherstkov, V. F.,Sterlin, S. R.,Vasil'ev, Yu. B.,German, L. S.
p. 1670 - 1673
(2007/10/02)

NEW SYNTHESIS OF POLYCHLORO(TRIFLUOROMETHYL)BENZENES AND HIGHLY STRAINED POLYCHLORO(TRICHLOROMETHYL)BENZENES
Several polychloro(trifluoromethyl)benzenes have been prepared by treatment of the corresponding polychlorobenzenes with CCl3F and AlCl3.The resulting trifluoromethyl derivatives, by reaction with the same inorganic halide in CS2, give their trichloromethyl analogues.
Riera, Juan,Castaner, Juan,Carilla, Jose,Robert, Ana
p. 3825 - 3828
(2007/10/02)

Synthesis and characterization of (trifluoromethyl)gold complexes
The synthesis of (CF3)AuL (L = PMe3, PEt3, PPh3) from LAuCl and Cd(CF3)2·DME is described. These linear gold(I) compounds readily add excess halogen to form the predominantly trans square-planar gold(III) dihalides (CF3)AuX2(L) (X = Br, I). The use of stoichiometric (or less) halogen leads to a significant quantity of (CF3)2AuX(L) (L = PMe3, PEt3) which is shown to arise from trifluoromethyl/halogen ligand exchange between (CF3)AuL and (CF3)AuX2(L). No evidence for ligand exchange is found when L = PPh3. (CF3)2AuI(L) (L = PMe3, PEt3) may also be prepared in 80% yield from the oxidative addition of trifluoromethyl iodide to (CF3)AuL; experiments with the radical scavenger galvinoxyl suggest a radical chain mechanism for this CF3I addition. Close examination of the 1H and 19F NMR spectra for the new square-planar complexes reveals that downfield shifts occur for both nuclei when a cis halide is changed from Br to I; a trans halide causes an upfield shift upon this substitution. The cadmium reagent is, in general, ineffective for the preparation of Au(III) complexes since reduction to (CF3)AuL usually occurs. However, treatment of (CF3)2AuI(PMe3) with Cd(CF3)2·DME in the presence of excess CF3I leads to the high-yield synthesis of the tris(trifluoromethyl) species (CF3)3AuPMe3.
Sanner, Robert D.,Satcher Jr., Joe H.,Droege, Michael W.
p. 1498 - 1506
(2008/10/08)

ON SOME NEW TRIFLUOROMETHYL IODINE(III) COMPOUNDS: REACTIONS OF CF3IF2 WITH BORON AND SILICON COMPOUNDS AND CF3ICl2 WITH SILVER SALTS
CF3IF2 undergoes fluorine exchange reactions with BX3 (X = Cl, Br, I, OCOCF3) to form the compounds CF3IX2.The reactions of CF3IF2 with (CF3)2BN(CH3)2, (CH3)3SiNCO and (CH3)3SiN(CH3)COCF3 yield the corresponding new trifluoromethyl iodine (III) nitrogen compounds.A preparative method for the synthesis of CF3ICl2 is found by reacting CF3IF2 with (CH3)3SiCl.CF3ICl2 reacts with AgX (X = OCOCF3, SCF3) to yield the corresponding CF3IX2 compounds and with (C6H5)4AsCl the novel ion (-) is detected.Products were identified by n.m.r. spectroscopy.
Tyrra, Wieland,Naumann, Dieter
p. 401 - 416
(2007/10/02)

Thiocarbonyl Fluoride in the Solvent System Hydrogen Fluoride: Preparation and Reactions of Halogenated Thiocarbenium Ions
Solvolysis of thiocarbonyl fluorides 1b, c in HF/SbF5 or FSO3H/SbF5 yields dithietane-2-ylium ions 2b, c, respectively.Reactions of 2b, c with the base F in the solvent system HF give the dithietanes 3b, c.The acidity dependance of the formation of 2b, c is demonstrated by gradation of the acidic strength with NbF5 and F(1-).The existence of thioacylium ions 5b, c in solutions of extremely high acidity is concluded from NMR spectroscopic data.The results of the solvolysis reactions are confirmed by thioacylation of the aromatic compounds 6a-d in the HF system leading to trifluoromethyl dithiobenzoates 7a-d.Among the corresponding carbonyl fluorides only 4 exhibits comparable basic properties in superacids.
Haas, Alois,Wanzke, Wolfgang
p. 429 - 434
(2007/10/02)

DEPENDENCE OF THE UNIMOLECULAR DISSOCIATION PRODUCTS ON THE FLUENCE OF THE CO2 LASER BEAM
The dissociation products of CF2Cl2 irradiated in the line P20 at 9.17 μm with pulses of fluence as high as 60E4 J*m-2 depend on the pressure of the gas, giving rise to C2F4 only when the pressure is of the order of 2 mb.At remarkably lower fluence (2E4 J*m-2) this product appears however in a wide range of pressures. For CF2HCl, C2F4 is the only product that appears at fluences as high as 60E4 J*m-2).At lower fluences (2.5E4 J*m-2), less C2F4 is produced and another product, probably a halogenated derivative of butane, is obtained.
Santos, M.,Hernandez-Vara, R.,Herreros, J. M.,Gonzales-Diaz, P. F.
p. 533 - 536
(2007/10/02)

FLUOROCARBON-SELENIUM CHEMISTRY: ACCOMPLISHMENTS AND QUESTS
The binary selenium fluorides SeFn (n = 2, 4, 6) and Se2F2 are considered along with corresponding perfluorohalogenoorganoselenium compounds with selenium in the oxidation states 1, 2, 4 and 6.For lower selenium fluorides, preparation and characterisation are emphasized.Recent results in the chemistry of SeCF2, CF3SeCl, CF3SeSeCF3, CF3Se(O)OM and CF3SeVI-compounds are presented.A comparison with the correspondig sulfur chemistry is also provided.
HAAS, A.
p. 415 - 440
(2007/10/02)

CH3(.) vs. CF3(.): Relative Rates of Formation from β-Scission
The relative rates of formation of CH3(.) and CF3(.) from β-scission reactions of trifluoro-t-butoxy radical (1) have been measured to be about 10:1 by thermolysing both trifluoro-t-butyl hypochlorite (4) and bis(trifluoro-t-butyl) peroxydicarbonate (14) in CCl4 at 160 and 140 deg C.
Jiang, Xi-Kui,Li, Xing-Ya,Wang, Ke-Yang
p. 745 - 746
(2007/10/02)

(Trifluoromethyl)selenium(VI) Compounds, Synthesis and Properties of Tetrafluoro(trifluoromethyl)selenium Halides and Trifluoromethaneselenonates
Fluorination of CF3SeF3 with liquid F2 or AgF2 leads to CF3SeF5, which decomposes to CF4 and SeF4.With water CF4 and SeOF2 are formed.Addition of ClF to CF3SeF3 gives CF3SeF4Cl, which splits mainly into CF3Cl and SeF4.Hydrolysis provides analogously CF3Cl and SeOF2.A neutral concentrated solution of KMnO4 oxydizes CF3SeO2H in water in good yields to CF3SeO3K, the free acid of which is obtained with 74percent HClO4.The aqueous solution can be concentrated up to 90percent, but above this concentration spontaneous decomposition to CF4, COF2, and SeO2 occurs.Trifluoromethaneselenonates are stable at room temperature but decompose when heated.
Haas, Alois,Weiler, Hans-Ulrich
p. 943 - 951
(2007/10/02)

REACTIONS OF BIS(TRIFLUOROMETHYL)NITROXYL WITH (CF3)2AsX (WHERE X = F, Cl and Br)
(CF3)2AsX (X = F, Cl) give at elevated temperatures substitution reactions with (CF3)2NO to afford (CF3)2NOAs(CF3)X and (CF3)2NOCF3.The formation of addition products at low temperatures to give 2As(CF3)2X, followed by elimination reactions at elevated temperatures to give the final products provide for the first time direct evidence for the mechanisms of the substitution reactions.With (CF3)2AsBr, bromine was initially displaced to afford (CF3)2NOAs(CF3)2, followed by addition reactions to give 3As(CF3)2.
ANG, H. G.,SO, K. K.
p. 433 - 450
(2007/10/02)

SUBSTITUTIVE AROMATIC FLUORINATION WITH CHLORINE PENTAFLUORIDE
In contrast to limited substitutive fluorination of aromatics with halogen fluorides such as ClF, ClF3, BrF3 and IF5, fluorination is the predominant reaction path with ClF5.Under non-catalytic liquid phase conditions, benzene was converted to fluorobenzene (54percent yield) and chlorobenzene (37percent yield), respectively.For a heterocyclic substrate, i.e. 2,4,6-trifluoropyrimidine, sunstitutive fluorination predominated over chlorination.Three possible fluorination mechanisms are discussed.A transition complex of ClF5 with benzene is favored.Enhanced exchange fluorination of CCl4 was effected with ClF5 (CF2Cl2 >> CFCl3 > CF3Cl) as compared with ClF3 (CFCl3 >> CF2Cl2)
Boudakian, Max M.,Hyde, Gene A.
p. 435 - 446
(2007/10/02)

THERMOLYSE DES HALOGENURES DE PERFLUOROALCANESULFONYLE
Perfluoroalkanesulfonyl chlorides FSO2Cl; RF= CF3, C2F5, C4F9>, decompose thermally to give the corresponding perfluoroalkyl chlorides with evolution of SO2.The latter retards the reaction, but it is catalysed by copper which also inhibits the SO2 effect. 2-methyl-2-nitrosopropane traps the perfluoroalkyl free radicals.In the presence of a perfluoroalkyl iodide FI; R'not equal RF>, other products, RFI and RFCl, are obtained.A free radical chain-mechanism is then suggested.On the other hand, perfluorobutanesulfonyl fluoride is very stable thermally.
Oudrhiri-Hassani, M.,Brunel, D.,Germain, A.,Commeyras, A.
p. 491 - 504
(2007/10/02)

REACTION OF CHLORINE FLUOROSULFATE AND PEROXYDISULFURYL DIFLUORIDE WITH PERFLUORONITROSOALKANES
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Fokin, A. V.,Studnev, Yu. N.,Rapkin, A. I.,Krotovich, I. N.,Chilikin, V. G.,Verenikin, O. V.
p. 766 - 769
(2007/10/02)

Further reactions of chlorine(I) and bromine(I) trifluoromethanesulfonate and bromine(I)fluorosulfate
Substitutive electrophilic dehalogenation reactions of CF3SO2OX (X=Cl,Br) are reported with some covalent inorganic chlorides. These reactions result in the formation of XX′(X,X′Cl,Br) and several new trifluoromethanesulfonate derivatives in excellent yields. Chlorine(I) trifluoromethanesulfonate also oxidatively adds to unsaturated inorganic substrates such as CO, SO2 and SF4 forming new compounds. The reactivity of CF3SO2OCl is rather similar to that of FSO2OBr and some comparisons between the two are given.
Johri, Kamalesh K.,Katsuhara, Yutaka,DesMarteau, Darryl D.
p. 227 - 242
(2007/10/02)

DISPROPORTIONATION OF FREONS OF THE METHANE SERIES ON ZnAl2O4
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Chernyuk, G. P.
p. 1163 - 1167
(2007/10/02)

Bis, N-Chlorobis(F-methyl)sulfimide, and N-Fluorobis(F-methyl)sulfimide
The first member of a new class of stable sulfimides, bis, (CF3)2S=NN=S(CF3)2, results from the photolysis of (CF3)2S=NCl.The latter is prepared by reacting (CF3)2S=NH with ClF in the presence of CsF.Under similar conditions, (CF3)2S=NH reacts with SF4 to give (CF3)2S=NF.
Kumar, Ramesh C.,Shreeve, Jean'ne M.
p. 1951 - 1952
(2007/10/02)

Kinetics and Mechanism of the Joint Gas-phase Bromination and Chlorination of Trifluoromethane
Preliminary data have been obtained for the kinetics of the joint bromination and chlorination of trifluoromethane.In the presence of chlorine bromination (the formation of bromotrifluoromethane) takes place preferentially.The addition of chlorine to the system greatly increases the rate of reaction.It is shown that the acceleration of the bromination in the presence of chlorine can be accounted for by the reaction between atomic bromine and molecular chlorine to give molecular chlorobromine and atomic chlorine, and also by the reaction of atomic chlorine with molecular bromine to form a molecule of chlorobromine and atomic bromine.Analytical expressions have been obtained for the rate of reaction as well as the ratio of bromotrifluoromethane and chlorotrifluoromethane formed.These expressions are consistent with experiment.
Zhdanov, G. F.,Poluektov, V. A.,Belevtsev, E. G.,Orlov, G. D.
p. 1135 - 1137
(2007/10/02)

Arrhenius Parameters for the Reaction of Trifluoromethyl Radicals with Cyanogen Chloride
The reaction of CF3 radicals with ClCN has been studied over a wide temperature range, 268-693 K, using CF3 radicals generated by the photolysis of CH3I.Over the range 408-473 K, CF3COCF3 was also used as a CF3 radical source.The radicals react with ClCN by addition followed by decomposition of the adduct and by chlorine abstraction: .The Arrhenius plot for this reaction is strongly curved.Using data from the low- and high-temperature regions, the following expressions for the rate constants for addition reaction (1) and chlorine abstraction (3) relative to CF3 recombination have been obtained: .The combination of E1 with the difference E-1-E2, which can be estimated, gives an upper limit for ΔH03 from which an approximate value of ΔH0f(CN) of 393.4 kJ mol-1 or less has been obtained.
Cosa, Fernando,Oexler, Elena V.,Staricco, Eduardo H.
p. 253 - 260
(2007/10/02)