- Electronic Spectroscopy of CF3O in a Supersonic Jet: Symmetry and Rotational Structure of a Prototypical Perfluoroalkoxy Radical
-
The electronic transition of CF3O was observed in a supersonic yet using laser-induced fluorescence.Rotational analysis of the high-resolution spectrum of the origin band is consistent with CF3O having C3ν symmetry in both its ground and excited electronic states.The lowest level is best described as 2E3/2 with residual unquenched electronic angular momentum, leading to a significant spin-orbit splitting.
- Tan, Xue-Qing,Yang, Min-Chieh,Carter, Christopher C.,Williamson, James M.,Miller, Terry A.,et al.
-
-
Read Online
- Multiple Infrared Photon Dissociation and Kinetics of CF3O Radicals
-
The multiple infrared photon dissociation of CF3O radicals generated from bis(trifluoromethyl) peroxide has been investigated.Infrared fluorescence from HF, formed by reaction of the liberated F atom with HI, was used to monitor the dissociation over a range of infrared fluences.A simple rate equation model has been used to interpret the multiphoton excitation and dissociation of the CF3O species.The kinetics of the recombination reaction, CF3O + F CF3OF, have been investigated by scavenging the F atoms with added HI.The rate constant for this reaction at 300 K is determined to be (3.5+/-0.5)E10 L mol-1 s-1.
- Zhang, Fumin,Francisco, J. S.,Steinfeld, J. I.
-
-
Read Online
- Catalytic microreactor with electrodeposited hierarchically nanostructured nickel coatings for gas-phase fluorination reactions
-
The fabrication of a catalytic microreactor for the reaction of undiluted carbonyl difluoride and elemental fluorine to synthesize trifluoromethyl hypofluorite, CF3OF, on CsF catalyst supported on F2-passivated nanosctructured Ni coating was studied. The nanosctructured Ni support for catalyst immobilization was electrodeposited by a two-step procedure, consisting of a low current density step followed by a brief high current density one, for a hierarchical differentiation of structural features. An aqueous solution of NiCl2 with diethanolamine, as crystal modifier, and sodium lauryl sulphate, as anti-pitting agent, was used as electrolyte. Constant-pH Ni electrocrystallization was performed on H2SO4-etched Cu substrates in a range of pH from 1 to 4 via a HCl/H3BO3 based buffer. Passivation was carried out under up to 300 mbar of undiluted F2. XRD, XPS, SEM, AFM, and static contact angle measurements were performed. Ni coatings obtained from pH 3 electrolytes were selected for microreactor fabrication on the basis of characterization data, due to the reproducibility and homogeneity of the structured Ni layers. The catalytic microreactor allowed the quantitative production of CF3OF from pure reactants, on demand, and removing any criticality relative to thermal and safety control of the synthesis. The CF3O-group selective transfer ability of the synthetized hypofluorite has raised interest in pharmaceutical and agrochemical industries in recent years.
- Sansotera, Maurizio,Baggioli, Alberto,Ieffa, Simona,Tedesco, Mariella,Sacchi, Benedetta,Bianchi, Claudia L.,Navarrini, Michele,Migliori, Massimo,Magagnin, Luca,Navarrini, Walter
-
-
- Method of synthesis and purification for trifluoromethyle hypofluorite
-
The present invention relates to a method for synthesizing and purifying trifluoromethyl hypofluorite (CF_3OF) of high purity by performing reaction of F_2 gas and COF_2 gas in the presence of a metal fluoride catalyst. The method for synthesizing and purifying CF_3OF comprises: a synthesis step (S10) of mixing F_2 gas and COF_2 gas in a reactor for a solid catalyst and performing reaction thereof; a step (S20) of primarily purifying the synthesized mixed gas (CF_3OF) in a primary purifier having the lower temperature than the boiling point; a step (S30) of secondarily purifying the primarily purified gas (CF_3OF) in a secondary purifier having the higher temperature than the boiling point.COPYRIGHT KIPO 2017
- -
-
Paragraph 0080-0087
(2017/09/21)
-
- Direct fluorination of carbon monoxide in microreactors
-
Many attempts to obtain a clean stream of COF2 have been carried out in the past by means of the direct fluorination of carbon monoxide with elemental fluorine or by electrochemical fluorination. The reaction is highly exothermic, therefore dif
- Navarrini, Walter,Venturini, Francesco,Tortelli, Vito,Basak, Soubir,Pimparkar, Ketan P.,Adamo, Andrea,Jensen, Klavs F.
-
-
- Process for preparing fluorohalogenethers
-
A process for preparing fluorovinylethers having general formula: [in-line-formulae]RfO—CF═CF2 ??(IA)[/in-line-formulae]wherein Rf is a fluorinated or perfluorinated alkyl or cycloalkyl substituent; comprising the following reaction steps:1) reaction of a hypofluorite of formula RfOF, wherein Rf is as above, with an olefin of formula: [in-line-formulae]CY″Y═CY′CI ??(II)[/in-line-formulae]wherein Y, Y′ and Y″, equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y′ and Y″ are not contemporaneously hydrogen;2) dehalogenation or dehydrohalogenation of the fluorohalogenethers obtained in step 1) and obtainment of vinyl ethers of formula: [in-line-formulae]RfO—CYI═CYIIF ??(IV)[/in-line-formulae]wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H;3) fluorination with fluorine of the vinyl ethers (IV) and obtainment of fluorohalogenethers of formula: [in-line-formulae]RfO—CFYI—CF2YII ??(I)[/in-line-formulae]wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H;4) dehalogenation or dehydrohalogenation of the fluorohalogenethers (I) and obtainment of the fluorovinylethers (IA).
- -
-
Page/Page column 4
(2008/06/13)
-
- Process for preparing fluorohalogenethers
-
A process for preparing perfluorovinylethers having general formula: [in-line-formulae]RfO—CF═CF2 ??(IA)[/in-line-formulae] wherein Rf is a C1-C3 alkyl perfluorinated substituent; comprising the following steps: 1a) fluorination with fluorine of olefins of formula: [in-line-formulae]CY″Y═CY′Cl ??(II)[/in-line-formulae]wherein Y, Y′ and Y″, equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y′ and Y″ are not contemporaneously hydrogen; and obtainment of fluorohalogencarbons of formula: [in-line-formulae]FCY″Y—CY′ClF ??(III)[/in-line-formulae]wherein Y, Y′ and Y″ are as above; 2a) dehalogenation or dehydrohalogenation of the fluorohalogencarbons (III) and obtainment of fluorohalogen olefins of formula: [in-line-formulae]FCYI═CYIIF ??(IV)[/in-line-formulae]wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H; 3a) reaction between a hypofluorite of formula RfOF and a fluorohalogenolefin (IV), obtaining the fluorohalogenethers of formula: [in-line-formulae]RfO—CFYI—CF2YII ??(I)[/in-line-formulae]wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H; 4a) dehalogenation or dehydrohalogenation of the compounds (I) and obtainment of the perfluorovinylethers (IA).
- -
-
Page/Page column 4
(2008/06/13)
-
- Process for preparing fluorohalogenethers
-
A process for preparing fluorovinylethers having general formula: ???????? RfO-CF=CF2,?????(IA) wherein Rf is a fluorinated or perfluorinated alkyl or cycloalkyl substituent; comprising the following reaction steps: 1) reaction of a hypofluorite of formula RfOF, wherein Rf is as above, with an olefin of formula: ???????? CY"Y=CY'Cl?????(II) wherein Y, Y' and Y", equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y' and Y" are not contemporaneously hydrogen; 2) dehalogenation or dehydrohalogenation of the fluorohalogenethers obtained in step 1) and obtainment of vinyl ethers of formula: ???????? RfO-CYI=CYIIF?????(IV) wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H; 3) fluorination with fluorine of the vinyl ethers (IV) and obtainment of fluorohalogenethers of formula: ???????? RfO-CFYI-CF2YII?????(I) wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H; 4) dehalogenation or dehydrohalogenation of the fluorohalogenethers (I) and obtainment of the fluorovinylethers (IA).
- -
-
Page/Page column 7
(2008/06/13)
-
- Process for preparing fluorohalogenethers
-
A process for preparing perfluorovinylethers having general formula: ???????? RfO-CF=CF2?????(IA) wherein Rf is a C1-C3 alkyl perfluorinated substituent; comprising the following steps: 1a) fluorination with fluorine of olefins of formula: ???????? CY"Y=CY'Cl?????(II) wherein Y, Y' and Y", equal to or different from each other, are H, Cl, Br, with the proviso that Y, Y' and Y" are not contemporaneously hydrogen; and obtainment of fluorohalogencarbons of formula: ???????? FCY"Y-CY'ClF?????(III) wherein Y, Y' and Y" are as above; 2a) dehalogenation or dehydrohalogenation of the fluorohalogencarbons (III) and obtainment of fluorohalogen olefins of formula: ???????? FCYI=CYIIF?????(IV) wherein YI and YII, equal to or different from each other, have the meaning of H, Cl, Br with the proviso that YI and YII are not both H; 3a) reaction between a hypofluorite of formula RfOF and a fluorohalogenolefin (IV), obtaining the fluorohalogenethers of formula: ???????? RfO-CFYI-CF2YII?????(I) wherein YI, YII, equal to or different from each other, are Cl, Br, H with the proviso that YI and YII cannot be contemporaneously equal to H; 4a) dehalogenation or dehydrohalogenation of the compounds (I) and obtainment of the perfluorovinylethers (IA).
- -
-
Page/Page column 8-9
(2008/06/13)
-
- Reaction between carbon dioxide and elementary fluorine
-
Reactions between carbon dioxide and fluorine were examined at temperatures of 303-523 K under various pressure and mixture ratios of both gases. Reactions were carried out similarly under the existence of NaF, CsF and EuF3. After the reaction, fluorine was removed and the reaction products were analyzed using FT-IR, GC/FT-IR and GC/MS. The major products were CF3OF, COF2, CF4 and CF2(OF)2. The best yield of COF2 was 11.1% under the reaction condition of CO2/F2 = 76 kPa/76 kPa with temperature of 498 K for 72 h in a direct reaction. The formation rate of COF2 in the direct reaction was estimated as 0.232 dm3 mol-1 h-1 under the reaction conditions of CO2/F2 = 76 kPa/76 kPa, at 498 K. In the presence of CsF, it was estimated as 1.88 dm3 mol-1 h-1 at CO2/F2 = 76 kPa/76 kPa at 498 K. The activation energy of the COF2 formation in the direct reaction was estimated as 45.7 kJ mol-1 at CO2/F2 = 76 kPa/76 kPa at 498 K. In addition, 24.2 and 38.9 kJ mol-1 were evaluated at CO2/F2 = 76 kPa/76 kPa at 498 K, respectively, in the presence of CsF and EuF3.
- Hasegawa, Yasuo,Otani, Reiko,Yonezawa, Susumu,Takashima, Masayuki
-
-
- Synthesis and reaction chemistry of fluoroxydifluoromethyl fluoroformyl peroxide
-
The reaction of bis(fluoroformyl) peroxide 1 with F2 in the presence of CsHF2 of KHF2 produces FOCF2OOC(O)F 2 in 60% yield. The previously known FOCF2OOCF2OF is also obtained as a byproduct along with small amounts of the new compounds FOCF2OOC(O)OOC(O)F 3 and FOCF2OOC(O)OOCF2OF 4. Hydrolysis of 2 affords either FOCF2OOC(O)OOCF2OF 4 or FOCF2OOH 5 in low yield, depending on the reaction conditions. Fluorination of peroxides 3-5 provides the corresponding fluoroxy compounds in high yields and provides further proof of structure.
- Huang, Qun,Desmarteau, Darryl D.
-
p. 361 - 366
(2007/10/03)
-
- On the reaction of perfluoro-aza-propene with oxygen difluoride and fluorination of bis(trifluoromethyl)-hydroxylamine
-
The reactions of perfluoro-aza-propene CF3NCF2 with an excess of oxygen difluoride OF2 and the fluorination of bis(trifluoromethyl)-hydroxylamine (CF3)2NOH are discussed. Additionally, we present density functional calculations (B3LYP/6-31G*) on bis(trifluoromethyl)-hypofluorite (CF3)2NOF, which clearly show that this molecule is a model substance for the discussion of negative hyperconjugation.
- Minkwitz, Rolf,Reinemann, Stefan,Ludwig, Ralf
-
p. 145 - 149
(2007/10/03)
-
- A photoionization study of trifluoromethanol, CF3OH, trifluoromethyl hypofluorite, CF3OF, and trifluoromethyl hypochlorite, CF3OCl
-
CF3OH, an important and controversial by-product of atmospheric decomposition of CF3CFH2 (HFC-134a) and other hydrofluorocarbons, has been examined by photoionization mass spectrometry. The ionization onset is characterized by a broad Franck-Condon distribution, arising primarily from a substantial elongation of the C-O bond upon ionization. An upper limit to the adiabatic ionization potential (IP) of ≤ 13.08 ± 0.05 eV has been established. The appearance potentials (APs) of the first two fragments have been accurately determined by fitting with appropriate model functions as AP0(CF2OH+/CF 3OH)≤13.830±0.005 eV and AP0(CF+3/CF 3OH)≤13.996±0.005 eV. While the exact nature of the lowest-energy fragment (nominally CF2OH+) is not clear, the CF+3 fragment threshold leads unambiguously to ΔH°f 298(CF3OH)≥-217.2±0.9 kcal/mol and D298(CF3-OH)≤115.2±0.3 kcal/mol. With previously derived ΔH°f 298(CF3O)=-151.8+1.7-1.1 kcal/mol, this yields D298(CF3O-H) =117.5+1.9-1.4 kcal/mol, very close to, or only slightly weaker than the O-H bond energy in water: D298(CF3O-H)-D298(HO-H)=-1.8 +1.9-1.4 kcal/mol≈0 kcal/mol. Similarly, with the recently redetermined value for ΔH°f(CF2O), this implies a 298 K reaction enthalpy for the 1,2-elimination of HF from CF3OH of 2.81+1.7-1.1 kcal/mol. CF3OF and CF3OCl have also been examined by photoionization. CF3OF produces a very weak parent, with an apparent adiabatic IP(CF3OF) ≤12.710±0.007 eV. An analysis of the CF+3 and CF2O+ fragments from CF3OF, when combined with literature data, suggests ΔH°f 298(CF3OF)=-176.9+1.8-1.3 kcal/mol. The fitted value for the appearance potential of CF+3 from CF3OCl, AP0(CF+3/CF 3OCl)≤12.85±0.01 eV, leads to ΔH°f 298(CF3OCl)≥-175.6±1.0 kcal/mol, D298(CF3-OCl)≤88.4±0.3 kcal/mol, and D298(CF3O-Cl)≤52.8+2.0-1.5 is kcal/mol.
- Asher, Robert L.,Appelman, Evan H.,Tilson, Jeffrey L.,Litorja, Maritoni,Berkowitz, Joseph,Ruscic, Branko
-
p. 9111 - 9121
(2007/10/03)
-
- INVESTIGATIONS IN THE REGION OF INDUSTRIAL FLUORINATED COMPOUNDS
-
The synthesis and properties of ozone-friendly fluorohydrocarbons, fluoroolefins, and fluorinated compounds with functional groups (acids, alcohols, esters, and others), used for the creation of effective surfactants, ion-exchange membranes for various purposes, heat-resistant oils, and greases, were investigated.A technology was developed for the production of highly pure fluorinated compounds for microelectronics, fiber optics, and medicine.
- Maksimov, B. N.
-
p. 1935 - 1940
(2007/10/03)
-
- DIRECT GAS-PHASE CATALYTIC FLUORINATION OF PARTIALLY FLUORINATED ORGANIC COMPOUNDS
-
The fluorination of a wide range of polyfluorinated organic compounds with molecular fluorine in the gas phase in a layer of NiF2/support as catalyst was investigated.It was shown that the selectivity of fluorination of the series of fluoroolefins, acid fluorides, polyfluoroalkanes, and hydrogen-containing ethers can be greatly increased.The developed method was used on an industrial scale in the production of perfluorinated liquids.
- Zakharov, V. Yu.,Denisov, A. K.,Novikova, M. D.
-
p. 1942 - 1945
(2007/10/03)
-
- Process for preparing chlorotrifluoroethylene telomers and new telomers obtained
-
In the process for preparing chlorotrifluoroethylene telomers by reaction of chlorotrifluoroethylene with CF3 CF or Rx --CF2 OF (wherein Rx may be also a perfluoroalkyl radical having 1 to 10 carbon atoms), the content of telomers with end groups --F is increased or mixtures of telomers containing species with end groups --Cl are obtained by adding F2, according to particular modalities, to the reaction medium.
- -
-
-
- Process for preparing chlorotrifluoroethylene telomers and telomers obtained thereby
-
In the process for preparing chlorotrifluoroethylene telomers by reaction of chlorotrifluoroethylene with CF3OF or Rx-CF2OF the yield of telomers with -F end groups is increased or mix-tures of telomers containing species with -Cl end groups may be obtained by adding F2 to the reaction medium under certain operative conditions.
- -
-
-
- Facile, Temperature-Dependent Formation of Gaseous C1 and C2 Perfluoroalkyl Hypofluorites. Applications as Electrophilic Fluorinating Agents.
-
A convenient method for continuous-flow production of gaseous C1 and C2 fluoroxyperfluoroalkanes (RfOF) was developed.Passage of 10percent F2 through short columns of CF3CO2Na resulted in the formation of the following hypofluorites: CF3CF2OF, CF3OF, CF3CF(OF)2, and CF2(OF)2.No other significant oxidizing side products or residual F2 were present in the column effluent under normal conditions.Identifications of the hypofluorites were made through direct 19F NMR measurements at -40 deg C of the -196 deg C condensate of the column effluent and also on the basis of stilbene trapping experiments.Hypofluorites were formed rapidly at temperatures at least as low as -110 deg C but no reaction occurred at -160 deg C.The ratios of hypofluorites formed strongly depended on the temperature of the salt column.Yields of CF3CF(OF)2 exceeding 90percent, based on input F2, were obtained at salt temperatures between -110 and -78 deg C.At moderate temperatures (-20 to +20 deg C) CF3CF2OF was the predominant products, accompanied by significant amounts of CF3OF and CF3CF(OF)2 and traces of CF2(OF)2.CF3OF was the major hypofluorite formed at high (60 to 100 deg C) temperatures.No hypofluorites were detected when the column temperature was above 135 deg C.A minimum of specialized equipment is required to produce hypofluorites by this method.It makes expensive or previously exotic, little-studied fluoroxy compounds readily available for synthetic applications.Fluorinations of anisole, 3,4,6-triacetyl-D-glucal, phenylmercuric acetate, and N,N-dimethylphenylacetamide tert-butyldimethylsilyl enolate were carried out to demonstrate the synthetic utility of RfOF and to compare its chemical reactivity with acetyl hypofluorite, an electrophilic fluorinating agent currently in wide use.RfOF, used as a homogeneous reagent, was comparable in fluorinating ability but was less regio- and stereoselective than acetyl hypofluorite in the cases examined.
- Mulholland, G. Keith,Ehrenkaufer, Richard E.
-
p. 1482 - 1489
(2007/10/02)
-
- Fluorination of Aromatic Derivatives with Fluoroxytrifluoromethane and Bis(fluoroxy)difluoromethane
-
Fluoroxytrifluoromethane (CF3OF) and bis(fluoroxy)difluoromethane CF2(OF)2 are formed by the reaction of F2 with CO and CO2, respectively, over a CsF catalyst in a continouous-stream process.Both reagents react with aromatic substrates by an electrophilic substitution mechanism to yield fluoro-substituted derivatives.Fluorobenzene is produced in good yield from benzene, and aniline derivatives afford monofluorination products.Acetanilide (1), N-phenylmethanesulfonamide (2), α,α,α-trifluoroacetanilide (3), and 1,1,1-trifluoro(N-phenyl)methanesulfonamide (4) react with either reagent to yield mixtures of o- and p-fluoro-substituted derivatives.Solvent effects and competitive rate experiments demonstrate a preference for ortho substitution, especially in aprotic, nonpolar solvents.With particular substrates, these fluorinating agents are of practical synthetic utility, e.g., 2-fluoro-4-(trifluoromethyl)aniline is produced in high yield by fluorinating the intermediate 4-(trifluoromethyl)acetanilide (6) with CF3OF.Activated substrates such as toluene, xylenes, anisole, and cresols give mixtures of products which reduce the synthetic utility of these reagents.Nitrobenzene is fairly unreactive toward CF3OF and gives low yields of substitution products.
- Fifolt, Michael J.,Olczak, Raymond T.,Mundhenke, Rudolph F.
-
p. 4576 - 4582
(2007/10/02)
-
- Etude cinetique et analitique de l'oxydation du trifluorobromomethane entre 500 et 800 deg C. Coefficient negatif de temperature de la reaction
-
Kinetic and analytic studies of the oxidation of bromotrifluoromethane are performed by the pyrometer method between 500 and 800 deg C.The reaction is followed as a function of time by measuring the pressure variation.Among the formed products, some are analysed by colorimetry (bromine) infrared spectroscopy (CO2, CF2O, CF3OF, SiF4 and CF4) and polarography (mainly HF as a result of the hydrolysis reactions of F2, CF2O, CF3OF and SiF4).The fundamental fact lies in the appearance of a negative temperature coefficient for the CF3Br oxidation reaction, located beyond 670 deg C.It can be interpreted through the occurrence of the CF3O2 radical inverse formation reaction: CF3O2 --> CF3 + O2, whose activation energy is E ca. 157+/-8 kJ/mol.The higher stability of these CF3O2 radicals with regard to that of the alkyl peroxy radicals enables us to provide new material for an answer to the problem of the general extinction mechanism of hydrocarbon fires by this type of compound.
- Antonik, Stanislas
-
p. 117 - 123
(2007/10/02)
-
- OXYDATION ET COMBUSTION DES SYSTEMES H2-O2-N2-CF3Br ENTRE 400 ET 500 DEG C
-
The physico-chemical and analytic studies of the oxidation and combustion of the H2-O2-N2-CF3Br mixtures are performed by means of the pyrometer method between 400 and 500 deg C.The reaction is followed as a function of time by measuring the pressure variation and the light emission when flames appear.Some of the formed products are analysed by infra-red spectroscopy (CO2, CF2O, CF3OX with X = F and H, CF3H and FBrCO), and by polarography (mainly HX produced in the vessel on the one hand, and as a result of the hydrolysis reactions of halogens, CF2O, FBrCO and CF3OX on the other hand).In the considered temperature interval, the fundamental fact consists in replacing the branching chains oxidation reaction of hydrogen by a thermal chains reaction induced by the X2-H2 mixtures (mostly with the X2 = F2 mixture).The existence of these thermal chains might particularly explain why, on the whole, CF3Br is a rather bad inhibitor of the hydrogen flame.
- Lemahieu, Joseph,Antonik, Stanislas
-
p. 641 - 648
(2007/10/02)
-
- Some chemistry of difluoraminocarbonyl fluoride, NF2CFO. The preparation of perfluorourea, (NF2)2CO, and difluoraminocarbonyl chloride, NF2C(O)Cl. New preparations for NF2OCF3 and NF2<
-
Reactions of NF2CFO with CF3OF or with Al2Cl6 and HCl yield NF2OCF3 or NF2C(O)Cl, respectively. The reactions of NF2CFO with KF and CsF to give KOCF2NF
- Fraser, George W.,Shreeve, Jean'ne M.
-
p. 1711 - 1715
(2008/10/08)
-