353-50-4Relevant articles and documents
Kinetics of the Reactions of CF3Ox Radicals with NO, O3, and O2
Turnipseed, Andrew A.,Barone, Stephen B.,Ravishankara, A. R.
, p. 4594 - 4601 (1994)
The technique of pulsed laser photolysis/pulsed laser-induced fluorescence detection of CF3O was used to study the stratospherically important reactions of CF3O radicals with NO (k5), O3 (k4), and O2 (k6) and that of CF3OO
Atmospheric degradation mechanism of CF3OCF2H
Inoue,Kawasaki,Wallington,Hurley
, p. 296 - 302 (2001)
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
Tropospheric degradation products of novel hydrofluoropolyethers
Tuazon, Ernesto C.
, p. 1817 - 1821 (1997)
The Cl atom-initiated photooxidations of the hydrofluoropolyethers (HFPEs) HCF2OCF2OCF2CF2OCF2H, HCF2OCF2CF2OCF2H, and HCF2OCF2OCF2H in air produced C(O)F2 as the only carbon-containing product, with observed average C(O)F2 molar formation yields of 4.73, 3.77, and 2.82, respectively. The C(O)F2 molar formation yields during the early stages of the reactions were observed to be closer to the number of C atoms in each parent HFPE. On the basis of current knowledge concerning the degradation pathways of hydrofluorocarbons and hydrochlorofluorocarbons, it is expected that C(O)F2 will also be produced with near unit yield per C atom from the above HFPEs in the troposphere, where loss processes would be initiated primarily by reaction with OH radicals. The rate constants for reaction with the Cl atom at 298 ± 2 K were determined for the HFPEs by a relative rate method that employed CF3CF2H as the reference compound [κ(Cl + CF3CF2H) = (2.4 ± 0.5) x 10-16 cm3 molecule-1 S-1], with measured values of (in units of 10-17 cm3 molecule-1 s-1) HCF2OCF2OCF2CF2OCF2H, 3.6 ± 0.8; HCF2OCF2CF2OCF2H, 4.5 ± 1.0; and HCF2OCF2OCF2H, 5.0 ± 1.1.
Reaction Modulation Spectroscopy: A New Approach to Quantifying Reaction Mechanisms
Donahue, Neil M.,Demerjian, Kenneth L.,Anderson, James G.
, p. 17855 - 17861 (1996)
We report a new experimental method, reaction modulation spectroscopy, (RMS) that, shows great promise in enabling the systematic analysis of complicated oxidation mechanisms over the full range of atmospheric pressures and temperatures.The method is a form of difference spectroscopy in which we employ FTIR absorption spectroscopy in a high-pressure flow system (HPFS) where a plume of reacting species is examined before any significant fraction reaches the tube wall.The onest of the reaction is modulated by modulating the flow of an initiating radical species over a period that is short compared to any associated with experimental drifts.Spectra obtained with the radical source on and off are ratioed, giving a transmittance spectrum showing only the effects of the reaction modulation.The system is in a steady state, so signal averaging over long periods (up to several days) may be employed, if necessary, to obtain a high signal-to-noise ratio.Because no bulk reagents are disturbed in the process, we observe extremaly precise conservation of mass in the reaction plume.We illustrate the technique for the system OH + C3F6 (+O2, NOx,...) -> -> CF2O + CF3CFO, where we observe nearly 100percent conservatioin of odd-nitrogen species and roughly 90percent conservation of carbon under conditions chosen to force the reaction to completion, with residual spectra consistent with unidentified minor products having cross sections similar to the observed aldehydes.
Thermal Decomposition of CF3O2NO2
Mayer-Figge, A.,Zabel, F.,Becker, K. H.
, p. 6587 - 6593 (1996)
The unimolecular decomposition rate constant of CF3O2NO2 has been measured in detail as a function of temperature, pressure, and collision partner (M = N2, O2, NO).Temperatures were between 264 and 297 K, and total pressures ranged from 3 to 1013 mbar.The first-order decay of CF3O2NO2 in the presence of excess NO was followed in a temperature-controlled DURAN glass chamber by long-path IR absorption, using the absorption bands at 1768 and 1303 cm-1.At 1013 mbar, the first-order decomposition rate constants are best represented by the Arrhenius expression k3 = 5.7E15exp-1/RT> s-1 (2?).The temperature and pressure dependencies of k3 are well reproduced by the equation log(k3/k3,infinite) = log3,0/k3,infinite)/(1 + k3,0/k3,infinite)> + log(Fc)3,0/k3,infinite)/Nc>2>-1, Nc = 0.75-1.27 log(Fc) with the parameters k3,0/ = 2.4E-5exp(-78.4 kJ mol-1/RT) cm3 molecule-1 s-1, k3,infinite = 1.49E16exp-1/RT> s-1, Fc = 0.31, and k3,0(M=O2) ca. k3,0(M=N2).By combining the present decomposition rate constants with recombination rate constants k-3 from Caralp et al., the following thermochemical data for the equilibrium CF3O2NO2 CF3O2 + NO2 (k3,k-3) are derived from second- and third-law evaluations: ΔH0r,298 = 102.7 +/- 2.0 kJ mol-1, ΔS0r,298 = 163 +/- 7 J mol-1 K-1.The temperature dependence of the equilibrium constant between 200 and 300 K is described by the expression Kc = k3/k-3 = 3.80E27exp molecules cm-3.Consistency of the data on k3 (this work) and k-3 is shown by comparing experimental and theoretical limiting low-pressure rate constants, which lead to the reasonable value βc = 0.17 for the collision efficiency of N2.The present data confirm that CF3O2NO2 is thermally quite stable in the upper troposphere and lower stratosphere and that its lifetime is probably limited by photolysis in these regions of the atmosphere.
Kinetics and mechanism of gas-phase reactions of n-C4F 9OCH3, i-C4F9OCH3, n-C4F9OC(O)H, and i-C4F9OC(O)H with OH radicals in an environmental reaction chamber at 253-328 K
Chen,Uchimaru,Kutsuna,Tokuhashi,Sekiya
, p. 207 - 213 (2011)
The rate constants of the reactions of n-C4F9OCH 3 (k1), i-C4F9OCH3 (k2), n-C4F9OC(O)H (k3), and i-C4F9OC(O)H (k4) with OH radicals were studied in an 11.5-dm3 environmental reaction chamber. k1 and k2 were determined to be (1.44 ± 0.33) × 10 -12 exp[-(1450 ± 70)/T] and (1.59 ± 0.41) × 10-12 exp[-(1470 ± 80)/T] cm3 molecule-1 s-1 at 253-328 K. At 298 K, k3 and k4 were deduced to be (1.71 ± 0.32) × 10-14 and (1.67 ± 0.19) × 10-14 cm3 molecule-1 s -1. The observed products of the reaction of n-C4F 9OCH3 with OH radicals were n-C4F 9OC(O)H, CF3CF2CF2C(O)F, and COF2, and those for the reaction of i-C4F 9OCH3 were i-C4F9OC(O)H, (CF 3)2CFC(O)F, CF3C(O)F, and COF2.
Kinetics study of the gas-phase reactions of C2F 5OC(O)H and n-C3F7OC(O)H with OH radicals at 253-328 K
Chen,Kutsuna,Tokuhashi,Sekiya
, p. 563 - 568 (2004)
The rate constants, k1 and k2 for the reactions of C2F5OC(O)H and n-C3F7OC(O)H with OH radicals were measured using an FT-IR technique at 253-328 K. k1 and k2 were det
INFRARED FLUORESCENCE OF HYDROGEN FLUORIDE DURING MULTIQUANTUM DISSOCIATION OF A MIXTURE OF CF3OF WITH H2.
Aslanidi,Aslanidi,Zaburin,Zainullin,Turishchev
, p. 1182 - 1186 (1986)
The dissociation of molecules of trifluoromethyl hypofluoride CF//3OF in a mixture with hydrogen H//2 in the pulsed CO//2 laser emission field is discussed. This compound attracted attention because carbon-13 and oxygen-18 isotopes could possibly be obtained by laser excitation.
AN IMPROVED SYNTHESIS OF DICHLOROFLUORAMINE, FNCl2
Thrasher, Joseph S.,Desmarteau, Darryl D.
, p. 51 - 55 (1991)
Low-temperature fluorination of N,N-dichloro-1-fluoroformamide, FC(O)NCl2, has provided a more convenient, high-yield (75percent) synthesis of dichlorofluoramine, FNCl2, than was previously available.In an attempt to further expand the novel metal fluoride promted conversion of N-Cl bonds to N-Br bonds, both FC(O)NCl2 and FNCl2 were reacted with bromine in the presence of various alkali metal fluorides.No evidence was found for the formation of either FC(O)NBrCl and FC(O)NBr2 or FNBrCl and FNBr2 in these reactions.In fact, FC(O)NCl2 was found to decompose to C(O)F2, N2, and Cl2 in the presence of alkal metal fluorides.
Synthesis of Hexafluoroacetone by Catalytic Oxidation of Hexafluoropropylene
Igumnov,Lekontseva,Shipigusev,Gomzyakova,Soshin
, p. 170 - 171 (2001)
Oxidation of hexafluoropropylene with molecular oxygen in a fixed bed of a catalyst (activated carbon promoted with alkali metal fluorides) was studied.
Kinetic studies on the reactions of CF3 with O(3P) and H atoms at high temperatures
Takahashi, Kazuo,Sekiuji, Yoshinobu,Yamamori, Yasuyuki,Inomata, Tadaaki,Yokoyama, Keiichi
, p. 8339 - 8348 (1998)
The kinetics of the high-temperature reactions of CF3 radicals with O(3P) and H atoms has been investigated experimentally and theoretically. The product channels of the CF3 + O(3P) and CF3 + H reactions were examined by calculating their branching fractions with the multichannel Rice-Ramsperger-Kassel-Marcus (RRKM) theory. Structural parameters, vibrational frequencies, and threshold energy required for the RRKM calculation were obtained from an ab initio MO calculation. The theoretical calculation showed that the productions of CF2O + F and CF2(1A1) + HF were the unique possible channels for the CF3 + O(3P) and CF3 + H reactions, respectively, and that the other channels such as deactivation were negligible for both the reactions. The rate coefficients for these reactions were experimentally determined by using a shock tube-atomic resonance absorption spectroscopy technique over the temperature ranges of 1900-2330 and 1150-1380 K and the total density ranges of 8.2 × 1018-1.2 × 1019 and 6.1 × 1018-9.8 × 1018 molecules·cm-3. Nitrous oxide and ethyl iodide were used as precursors of electronically ground-state oxygen and hydrogen atoms, respectively. Trifluoromethyl radicals were produced through the thermal dissociation of CF3I. The rate coefficients for the reactions CF3 + O(3P) → CF2O + F (1b) and CF3 + H → CF2(1A1) + HF (2c) were obtained from the decay profiles of O- and H-atom concentrations as k1b = (2.55±0.23) × 10-11 and k2c = (8.86±0.32) ×10-11 cm3 molecule-1 s-1 (error limits at the one standard deviation level). Neither rate coefficient had any temperature or pressure dependence under the present experimental conditions; the values were in good agreement with some room-temperature data reported previously.
A kinetic and mechanistic study of the reactions of OH radicals and Cl atoms with 3,3,3-trifluoropropanol under atmospheric conditions
Kelly, Tanya,Bossoutrot, Valerie,Magneron, Isabelle,Wirtz, Klaus,Treacy, Jack,Mellouki, Abdelwahid,Sidebottom, Howard,Bras, Georges Le
, p. 347 - 355 (2005)
Product distribution studies of the OH radical and Cl atom initiated oxidation of CF3CH2CH2OH in air at 1 atm and 298 ± 5 K have been carried out in laboratory and outdoor atmospheric simulation chambers in the presence and absence of NOx. The results show that CF3CH2CHO is the only primary product and that the aldehyde is fairly rapidly removed from the system. In the absence of NOx the major degradation product of CF3CH2CHO is CF3CHO, and the combined yields of the two aldehydes formed from CF3CH2CH2OH are close to unity (0.95 ± 0.05). In the presence of NOx small amounts of CF3CH 2C(O)O2NO2 were also observed (3CHO is removed from the system to give mainly CF2O. The laser photolysis-laser induced fluorescence technique was used to determine values of k(OH + CF3CH 2CH2OH) = (0.89 ± 0.03) × 10-12 and k(OH + CF3CH2HO) = (2.96 ± 0.04) × 10-12 cm3 molecule-1 s-1. A relative rate method has been employed to measure the rate coefficients k(OH + CF3CH2CH2OH) = (1.08 ± 0.05) × 10-12, k(OH + C6F13CH2CH 2OH) = (0.79 ± 0.08) × 10-12, k(Cl + CF 3CH2CH2OH) = (22.4 ± 0.4) × 10-12, and k(Cl + CF3CH2CHO) = (25.7 ± 0.4) × 10-12 cm3 molecule-1 s -1. The results from this investigation are discussed in terms of the possible importance of emissions of fluorinated alcohols as a source of fluorinated carboxylic acids in the environment.
Elementary reaction of CF2(X) with O3: Primary products
Beiderhase,Hoyermann,Hack
, p. 95 - 112 (2000)
The reaction of CF2(X) with O3 has been investigated in a discharge flow reactor at room temperature and low pressure (p = 2.5 mbar). CF2(X) was produced by a microwave discharge of a mixture of CF2Br2/He. The reactants and products were detected by mass spectrometers (MS), which were connected to the flow systems via a continuous molecular beam sampling system. The following primary products were observed (CF2O3 (m/z = 98); CF2O (m/z = 47, 66); O2 (m/z = 32)). The reaction mechanism: CF2(X) + O3 ? CF2O3# → CF2O3 → CF2O+O2 (1) explains the observed primary products. The molecule with the empirical formula CF2O3 has been observed directly by MS; the structure is discussed. by Oldenbourg Wissenschaftsverlag, Muenchen.
Product distribution in the Cl-initiated photooxidation of CF 3C(O)OCH2CF3
Blanco,Barnes,Teruel, Mariano A.
, p. 950 - 954 (2010)
The product distribution and the mechanism of the reaction of Cl atoms with 2,2,2-trifluoroethyl 2,2,2-trifluoroacetate (TFETFA; CF3C(O)OCH 2CF3) were investigated using a 1080 L environmental chamber with in situ Fourier transform infrared (FTIR) spectroscopy detection. The experiments were performed at (296±2) K and atmospheric pressure (760±10) Torr of synthetic air free of NOx. A yield of (45W3)% was obtained for the CF3C(O)OC(O)CF3 formation. CF2O and CO were produced with estimated yields of 35 and 28%, respectively. No trifluoroacetic acid (TFA; CF3C(O)OH) was observed. The yields determined are rationalized in terms of the competitive reaction channels for the fluoroalcoxy radicals formed in the H-abstraction process: (a) reaction with O2, (b) C-C, C-O, C-H decomposition, and (c) a possible a-ester rearrangement pathway. The negligible importance of the a-ester channel, to produce TFA, was explained by the reduction of the stability of the five-membered transition state of the a-ester rearrangement. Atmospheric implications, particularly regarding the fluorocarboxylic acid formation, are discussed. Copyright
Evidence for the unimolecular decomposition of CF3OCF 3 to COF2 and CF4 by high energy irradiation
Waltman
, p. 378 - 381 (2013)
The decomposition of CF3OCF3 via electron beam irradiation in the gas phase and isolated in an argon matrix at T = 10 K is investigated via infrared spectroscopy. CF3OCF3 produces only COF2 and CF4. In the gas phase irradiation, the G value for CF3OCF3 decomposition is 5.9, and the G values for formation of COF2 and CF4 are 5.0 and 4.9, respectively. In the low temperature matrix isolated irradiation, CF 3OCF3 decomposition and COF2 evolution occur in a 1:1 ratio. The results strongly suggest that a unimolecular mechanism for the formation of COF2 is operative because the product yields in the gas phase and matrix exposures are similar.
Simons, J. H.,Bond, R. L.,McArthur, R. E.
, p. 3477 - 3480 (1940)
Sauer,Shreeve
, p. 501 (1970)
Temperature dependence of the gas-phase reactions F + CHFO, CFO + F, and CFO + CFO
Behr, Peter,Kaupert, Cornelia,Shafranovski, Eduard,Heydtmann, Horst
, p. 329 - 333 (1998)
The rate coefficients for the reactions CHFO + F, CFO + F and the self-reaction of CFO were determined over the temperature range of 222-298 K A computer controlled discharge-flow system with mass spectrometric detection was used. The results are expressed in the Arrhenius form (with energies in J) CHFO + F → CFO + HF: k1,(T) = (9.7 ± 0.7) · 10-12 exp[-(5940 ± 150)/RT] cm3 molecule cm-1 s-1 CFO + F + M → CF2O + M: k2(T) = (260 ± 1.17)·10-10 exp[-(10110 ± 1250)/RT cm3 molecule-1 s-1 CFO + CFO → CF2O + CO: k3(T) = (3.77 ± 2.7)·10-10 exp[-(8350 ± 28001/RT] cm3 molecule-1 s-1
Gaseous ion-molecule reactions of F(-), CF3(-), C2F5(-), CF3(+) and C2F5(+) with hexafluoropropene oxide
Su, Timothy,Hammond, Gerald B.,Morris, Robert A.,Viggiano, A. A.,Paulson, John F.,et al.
, p. 149 - 158 (1995)
The gas-phase reactions of F(1-), CF3(1-), C2F5(1-), CF3(1+) and C2F5(1+) with hexafluoropropene oxide (HFPO, C3F6O) have been studied using a selected ion flow tube (SIFT) instrument at 300 K.Reactions of C4F9(1-) and C3F7(1+) with HFPO have also been studied as secondary reactions.Reaction rate constants and product branching fractions were measured.The F(1-), CF3(1-) and C2F5(1-) ions react rapidly with HFPO.The major reaction process is the formation of CF2O and the corresponding negative products ions.A minor pathway is the production of the ion CF3O(1-).Another reaction channel of F(1-) and CF3(1-) with HFPO is the formation of C2F4 and the corresponding ions.C4F9(1-) ion reacts with HFPO by F(1-) transfer to produce C3F7O(1-).The C3F7(1+) ion is the only product observed for the reaction of CF3(1+) with HFPO.The C2F5(1+) ion reacts rapidly with HFPO.The major product is C3F7(1+) which, in turn, reacts with HFPO to regenerate C2F5(1+), forming a cationic catalytic cycle for the formation of the inferred neutrals C2F4O and C4F8O from HFPO.Both C2F5(1+) and C3F7(1+) react with HFPO to produce neutral C3F8 and the corresponding positive ions.A rather rapid association reaction was observed between C3F7(1+) and HFPO, forming the adduct C6F13O(1+).A systematic estimation for the enthalpies of formation for a series of perfluorinated neutrals and ionic species is also presented. - Keywords: Ion-molecule reactions; Hexafluoropropene oxide; Fluorine ion; Trifluoromethyl ion; F-ethyl ion; Reaction kinetics
A new approach to the synthesis of 2,2-difluoro-1,3-dioxolanes
Navarrini, W.,Bragante, L.,Fontana, S.,Tortelli, V.,Zedda, A.
, p. 111 - 118 (1995)
A direct and versatile way to prepare halogenated 2,2-difluoro-1,3-dioxolanes through the addition of bis(fluoroxy)difluoromethane (BDM) to halogenated alkenes (CF2=CFCF3, CF2=CFOCF2CF3, CF2=CHCF3, CF3CF=CFCF3, CFCl=CFCl, CFBr=CFBr, CCl2=CCl2, CHCl=CCl2, CHCl=CHCl, CH2=CHCl, CF2=CFCl, (CF3)2CFCF=CFCF3, CF2=CFBr, CF2=CF2) has been discovered. - Keywords: Synthesis; Difluorodioxolanes; NMR spectroscopy; IR spectroscopy; Mass spectrometry
Marsh,Heicklen
, p. 3008 (1966)
Noftle,Cady
, p. 1010,1011,1012 (1965)
The reaction of difluorodioxirane with caesium trifluoromethoxide
Huang, Qun,DesMarteau, Darryl D.
, p. 1671 - 1672 (1999)
The reaction of difluorodioxirane with caesium trifluoromethoxide in the presence of CsF forms CF3OOC(O)F and the new compounds CF3O(OCF2O)(n)OC(O)F (n = 1~3); 13C labeling shows that the dioxirane undergoes ring opening at the O-O bond.
Reactions of trifluoromethyl hypofluorite with sulfur and with other substances containing divalent sulfur
Bailey, Robert E.,Cady, George H.
, p. 1930 - 1932 (1970)
-
Lopez et al.
, p. 97 (1974)
Direct Trifluoromethoxylation without OCF3-Carrier through In Situ Generation of Fluorophosgene
Donnard, Morgan,Guérin, Thomas,Hanquet, Gilles,Leroux, Frédéric R.,Panossian, Armen,Saiter, Jérémy
supporting information, p. 3139 - 3147 (2021/06/26)
Owing to the high interest in the OCF3 group for pharmaceutical and agrochemical applications, trifluoromethoxylation received great attention in the last years with several new methods for this approach towards OCF3-comprising compounds. Yet, it most often requires the beforehand preparation of specific F3CO? transfer reagents, which can be toxic, expensive, unstable, and/or generate undesired side-products upon consumption. To circumvent this, the in-situ generation of gaseous fluorophosgene from triphosgene, its conversion by fluoride into the OCF3 anion, and the direct use of the latter in nucleophilic substitutions is an appealing strategy, which, although recently approached, has not been fully exploited. We disclose herein our efforts towards this aim.
Improved Access to Organo-Soluble Di- and Tetrafluoridochlorate(I)/(III) Salts
Kaupp, M.,Müller, R.,Pr?hm, P.,Riedel, S.,Schattenberg, C. J.,Schmid, J. R.,Sonnenberg, K.,Steinhauer, S.,Vo?nacker, P.
supporting information, p. 16002 - 16006 (2020/07/20)
A facile one-pot gram-scale synthesis of tetraalkylammonium tetrafluoridochlorate(III) [cat][ClF4] ([cat]=[NEt3Me]+, [NEt4]+) is described. An acetonitrile solution of the corresponding alkylammonium chloride salt is fluorinated with diluted fluorine at low temperatures. The reaction proceeds via the [ClF2]? anion which is structurally characterized for the first time. The potential application of [ClF4]? salts as fluorinating agents is evaluated by the reaction with diphenyl disulfide, Ph2S2, to pentafluorosulfanyl benzene, PhSF5. The CN moieties in acetonitrile and [B(CN)4]? are transferred in CF3 groups. Exposure of carbon monoxide, CO, leads to the formation of carbonyl fluoride, COF2, and elemental gold is dissolved under the formation of tetrafluoridoaurate [AuF4]?.
Reductive photo-chemical separation of the hexafluorides of uranium and molybdenum
Chemnitz, Tobias,Kraus, Florian,Petry, Winfried,Stene, Riane E.
supporting information, (2020/10/18)
Two new techniques are described for the separation of molybdenum hexafluoride (MoF6) from uranium hexafluoride (UF6). Both separation techniques utilize the differences displayed by the hexafluorides in their ability to absorb light in the near UV region. Because UF6 absorbs light in the near UV region and MoF6 does not, this observation was used to selectively reduce UF6 to uranium pentafluoride (UF5) through irradiation with 395 nm light in the presence of a suitable reducing agent. Two reducing agents were chosen for this study: gaseous, liquid, or super-critical carbon monoxide (CO) and liquid sulfur dioxide (SO2). Since MoF6 is not reduced under the reaction conditions described here, it may be removed via distillation from the uranium-containing sample after complete reduction of UF6 to solid UF5. The molybdenum- and uranium-containing samples were measured for purity through elemental analysis using microwave plasma atomic emission spectroscopy (MP-AES). Elemental analysis showed more than 98.8 % of the Mo had been removed from the U-containing samples. Further analyses of the samples were performed by X-ray powder diffraction and IR spectroscopy.
