- Nickel Fluorocarbene Metathesis with Fluoroalkenes
-
Alkene metathesis with directly fluorinated alkenes is challenging, limiting its application in the burgeoning field of fluoro-organic chemistry. A new nickel tris(phosphite) fluoro(trifluoromethyl)carbene complex ([P3Ni]=CFCF3) reacts with CF2=CF2 (TFE) or CF2=CH2 (VDF) to yield both metallacyclobutane and perfluorocarbene metathesis products, [P3Ni]=CF2 and CR2=CFCF3 (R=F, H). The reaction of [P3Ni]=CFCF3 with trifluoroethylene also yields metathesis products, [P3Ni]=CF2 and cis/trans-CFCF3=CFH. However, unlike reactions with TFE and VDF, this reaction forms metallacyclopropanes and fluoronickel alkenyl species, resulting presumably from instability of the expected metallacyclobutanes. DFT calculations and experimental evidence established that the observed metallacyclobutanes are not intermediates in the formation of the observed metathesis products, thus highlighting a novel variant of the Chauvin mechanism enabled by the disparate four-coordinate transition states.
- Harrison, Daniel J.,Daniels, Alex L.,Guan, Jia,Gabidullin, Bulat M.,Hall, Michael B.,Baker, R. Tom
-
supporting information
p. 5772 - 5776
(2018/05/14)
-
- A novel and efficient synthetic route to perfluoroisobutyronitrile from perfluoroisobutyryl acid
-
A novel synthetic route to perfluoroisobutyronitrile from perfluoroisobutyryl acid which has mild conditions and low toxicity is described. This study introduces detailed synthetic protocols and characterization including GC-MS, 13C NMR and 19F NMR spectroscopy of perfluoroisobutyryl acid, perfluoroisobutyryl chloride, perfluoroisobutyl amide and perfluoroisobutyronitrile. Besides, this route is superior to the established patent and shows potential application in high voltage electrical equipment.
- Wang, Yi,Sun, Mengting,Gao, Zhanyang,Zou, Lilin,Zhong, Lingyu,Peng, Ruichao,Yu, Ping,Luo, Yunbai
-
p. 37159 - 37164
(2018/11/26)
-
- Novel synthetic route to perfluoroallyl cyanide (PFACN) reacting perfluoroallyl fluorosulfonate with cyanide
-
A novel synthetic method for the preparation of perfluoroallyl cyanide CF2[dbnd]CFCF2CN (PFACN) is presented. This includes the addition – elimination reaction of cyanide anion with perfluoroallyl fluorosulfate CF2[dbnd]CF
- Tverdomed, Sergey N.,Hirschberg, Markus E.,Pajkert, Romana,Hintzer, Klaus,R?schenthaler, Gerd-Volker
-
-
- Decomposition characteristics of C5F10O/air mixture as substitutes for SF6 to reduce global warming
-
Sulfur hexafluoride (SF6) is widely used in the power industry but is a serious greenhouse gas. Many researchers committed to achieving sustainable development of the power industry are finding alternatives to SF6 gas. C5F10O performs well in terms of environmental protection, insulation, and safety and is a potential environment-friendly alternative gas. In this paper, the insulation and decomposition characteristics of C5F10O/air gas mixture were examined using gas-insulation performance test platform, and decomposition products were detected by gas chromatography–mass spectrometry. The formation mechanism and distribution of C5F10O decomposition products were analyzed through reactive molecular dynamics method and density functional theory. The influence of air on the decomposition of C5F10O was also evaluated. Results showed that the decomposition of C5F10O/air gas mixture mainly produces CF3[rad], C3F7[rad], C4F7O[rad], CO, CF2[rad], CF[rad], F[rad] and CF4. The breakdown voltage of C5F10O/air gas mixture decreased slightly after repeated breakdown tests, and CF4, C2F6, C3F8, C3F6, C4F10, CF2O were detected. These results can serve as a reference for the systematic comprehension of the decomposition characteristics of C5F10O/air gas mixture and for related engineering applications.
- Li, Yi,Zhang, Xiaoxing,Xiao, Song,Chen, Qi,Wang, Dibo
-
-
- Reaction system for preparing tetrafluoroethane-β-sultone and preparation method using the same
-
The present invention relates to a reaction system for preparing tetrafluoroethane-andbeta;-sultone and to a preparation method using the same. By using the reaction system for preparing tetrafluoroethane-andbeta;-sultone and the preparation method using the same, tetrafluoroethane-andbeta;-sultone can be prepared safely and easily at a high yield and a high purity at normal temperature and normal pressure, rapid heat generation can be avoided and the risk of explosion in processes due to pressurization is reduced, so that the reaction system and the preparation method are usefully used to prepare energy-related materials such as fuel cell electrolytes and the like derived from tetrafluoroethane-andbeta;-sultone, and in particular, are usefully used to prepare fluorine-based ionomers.COPYRIGHT KIPO 2017
- -
-
Paragraph 0119-0121
(2017/12/27)
-
- Gas cracking reaction device and its application
-
The invention provides a gas cracking reaction device and an application thereof. The device comprises a mixer, a gas preheater, a cracking device, a separator and a quench cooler. The device also comprises a powder temperature control heater. A powder outlet of the powder temperature control heater is arranged on the cracking device at the end close to the gas preheater and is communicated to the cracking device; the mixer, the gas preheater, the cracking device, the separator and the quench cooler are communicated in sequence through a pipeline; or the mixer, the gas preheater, the cracking device, the quench cooler and the separator are communicated in sequence through the pipeline. During a use process of the gas cracking reaction device, energy storing powder circulates in a cracking pipe, thereby playing a scouring role to clear away carbon deposition completely; the cracking pipe has no carbon deposition, so that temperature runaway phenomenon can be prevented; maintenance times can be reduced; and the service life of the cracking pipe can be prolonged. Besides, during the use process, the gas cracking reaction device can save energy, reduce side reactions and increase product yield.
- -
-
Paragraph 0056-0064
(2017/03/23)
-
- At the same time, preparation of trifluoro-vinyl chloride and tetrafluoroethylene, and method
-
The invention discloses a method for simultaneously preparing trifluorochloroethylene and tetrafluoroethylene. The method comprises the following steps: mixing monochlorodifluoromethane, dichlorofluoromethane and a diluent, performing copyrolysis reaction to generate pyrolysis gas, quickly cooling, washing by water and alkali in sequence, drying, compressing, rectifying and purifying to obtain trifluorochloroethylene and tetrafluoroethylene, wherein the molar ratio of monochlorodifluoromethane to dichlorofluoromethane is 1 to (1-4), the molar ratio of the diluent to the total amount of monochlorodifluoromethane and dichlorofluoromethane is 1 to (1-20), the reaction temperature is 500-1,200 DEG C, the reaction pressure is 0.1-1MPa, and the reaction retention time is 0.01-10 seconds. The method has the advantages of being simple in process, easy for industrialization and environment-friendly, and raw materials are easily available.
- -
-
Paragraph 0054; 0055
(2017/03/22)
-
- METHOD FOR PRODUCING TETRAFLUOROETHYLENE AND/OR HEXAFLUOROPROPYLENE
-
PROBLEM TO BE SOLVED: To provide a novel method for producing tetrafluoroethylene and/or hexafluoropropylene. SOLUTION: The method for producing tetrafluoroethylene and/or hexafluoropropylene comprises thermally decomposing a perfluoroalkane represented by the general formula (1) defined by CnF2n+2, where n represents an integer of 4-28.] COPYRIGHT: (C)2016,JPOandINPIT
- -
-
Paragraph 0053-0054; 0058
(2016/11/09)
-
- Perfluoroalkyl Grignard Reagents: NMR Study of 1-Heptafluoropropylmagnesium Chloride in Solution
-
We report on the generation of a perfluoroalkyl Grignard reagent (FRMgX) by exchange reaction between a perfluoroalkyl iodide (FR-I) and a Grignard reagent (RMgX). 19F NMR was applied to monitor the generation of n-C3F7MgCl. Additional NMR techniques, including 19F COSY, NOESY, and pulsed gradient spin-echo (PGSE) diffusion NMR, were invoked to assign peaks observed in 19F spectrum. Schlenk equilibrium was observed and was significantly influenced by solvent, diethyl ether, or THF.
- Guang, Jie,Hopson, Russell,Williard, Paul G.,Fujiu, Motohiro,Negishi, Kazuyuki,Mikami, Koichi
-
p. 5922 - 5928
(2016/07/23)
-
- METHOD OF PRODUCING TRIFLUOROETHYLENE
-
PROBLEM TO BE SOLVED: To provide an economically advantageous method for producing industrially useful trifluoroethylene with high productivity by using easily available HCFC-124 as raw material while not using any catalyst. SOLUTION: A method of producing trifluoroethylene includes the step of bringing a reductive compound and 1,1,1,2-tetrafluoro-2-chloroethane into contact with each other, without using any catalyst, at a temperature of 400-1200°C. COPYRIGHT: (C)2016,JPO&INPIT
- -
-
Paragraph 0056-0058; 0075
(2017/01/02)
-
- METHOD OF PRODUCING 2,3,3,3-TETRAFLUOROPROPENE AND 1,1-DIFLUOROETHYLENE
-
PROBLEM TO BE SOLVED: To provide an economically advantageous method that produces industrially useful HFO-1234yf and VdF by a single reaction associated with heat decomposition by use of easily available raw material. SOLUTION: This invention provides a method of producing 2,3,3,3-tetrafluoropropene and 1,1-difluoroethylene by a synthetic reaction associated with heat decomposition from a raw material composition comprising octafluorocyclobutane and methane. COPYRIGHT: (C)2015,JPOandINPIT
- -
-
Paragraph 0050-0054; 0059
(2016/12/22)
-
- Catalytic pyrolysis of CHF3 over activated carbon and activated carbon supported potassium catalyst
-
The catalytic activity of activated carbon (AC) and activated carbon supported potassium for the decomposition of CHF3 was investigated at temperatures between 873 and 1173 K and at a space velocity of 4300 h -1. It is found that activated carbon supported potassium shows high and relatively stable activity during the pyrolysis of CHF3 under the conditions studied. Compared with the gas phase reaction, the conversion of CHF3 increases by up to 10 times between 873 and 1123 K, with the major products being C2F4 and C3F6. Selectivities as high as 55% to C2F4 and 35% to C 3F6 are achieved under optimum conditions. The main byproduct HF readily reacts with K2O in the catalyst, converting the catalyst from K2O/AC into KF/AC. Selectivity to the major products remains relatively constant following this transformation.
- Han, Wenfeng,Kennedy, Eric M.,Liu, Huazhang,Li, Ying,Adesina, Adesoji A.,MacKie, John C.,Dlugogorski, Bogdan Z.
-
scheme or table
p. 698 - 703
(2010/09/12)
-
- Unimolecular rate constant and threshold energy for the HF elimination from chemically activated CF3CHFCF3
-
Combination of CF3CHF and CF3 radicals at room temperature generated chemically activated CF3CHFCF3 molecules with 95 ± 3 kcal/mol of internal energy that decompose by loss of HF, initially attached to adjacent carbons, with an experimental unimolecular rate constant of (4.5 ± 1.1) x 102 s-1. Density functional theory was used to model the unimolecular rate constant for HF elimination, kHF, to determine a threshold energy of 75 ± 2 kcal/mol.
- Duncan, Juliana R.,Roach, Michael S.,Stiles, Brooke Sibila,Holmes, Bert E.
-
experimental part
p. 6996 - 7002
(2011/02/16)
-
- Experimental and chemical kinetic study of the pyrolysis of trifluoroethane and the reaction of trifluoromethane with methane
-
A detailed reaction mechanism is developed and used to model experimental data on the pyrolysis of CHF3 and the non-oxidative gas-phase reaction of CHF3 with CH4 in an alumina tube reactor at temperatures between 873 and 1173 K and at atmospheric pressure. It was found that CHF3 can be converted into C2F4 during pyrolysis and CH2=CF2 via reaction with CH4. Other products generated include C3F6, CH 2F2, C2H3F, C2HF 3, C2H6, C2H2 and CHF2CHF2. The rate of CHF3 decomposition can be expressed as 5.2×1013[s-1]e -295[kJmol-1]/RT. During the pyrolysis of CHF3 and in the reaction of CHF3 with CH4, the initial steps in the reaction involve the decomposition of CHF3 and subsequent formation of CF2 difluorocarbene radical and HF. It is proposed that CH4 is activated by a series of chain reactions, initiated by H radicals. The NIST HFC and GRI-Mech mechanisms, with minor modifications, are able to obtain satisfactory agreement between modelling results and experimental data. With these modelling analyses, the reactions leading to the formation of major and minor products are fully elucidated.
- Han, Wenfeng,Kennedy, Eric M.,Kundu, Sazal K.,MacKie, John C.,Adesina, Adesoji A.,Dlugogorski, Bogdan Z.
-
scheme or table
p. 751 - 760
(2010/09/04)
-
- Preparation of trifluoroiodomethane via vapor-phase catalytic reaction between hexafluoropropylene oxide and iodine
-
Based on our previous investigation on the reaction mechanism to produce difluorocarbene and subsequent CF3I starting with CHF3 and I2, a new route for preparing CF3I at a relative low temperature, 200 °C, has b
- Yang, Guang-Cheng,Jia, Xiao-Qing,Pan, Ren-Ming,Quan, Heng-Dao
-
experimental part
p. 985 - 988
(2010/02/28)
-
- Depolymerization of Fluoropolymers
-
A process for depolymerizing fluoropolymers includes continuously feeding a solid fluoropolymer, in particulate form, into a horizontal cylindrical first reaction zone. The fluoropolymer particles enter the first reaction zone at one end. Within the first reaction zone, a central axle from which protrudes at least one paddle, continuously rotates. The rotating paddle serves to advance the fluoropolymer particles along the reaction zone while agitating them. As the fluoropolymer particles pass along the reaction zone, they are subjected to an elevated temperature, thereby depolymerizing the fluoropolymer into a fluoro-containing compound-rich gas phase. A residual solids phase is withdrawn at the other end of the first reaction zone, as is the gas phase. Optionally, the gas phase is passed through a second reaction zone which is also at an elevated temperature. The gas phase is quenched, thereby to recover the fluoro-containing compounds as gaseous products.
- -
-
Page/Page column 4-5
(2009/06/27)
-
- Decomposition of pentafluoroallyl fluorosulfate oxide
-
Decomposition of pentafluoroallyl fluorosulfate oxide under nucleophilic catalysis is studied. The possible reaction mechanism is considered.
- Lebedev,Berenblit,Troichanskaya,Gubanov
-
experimental part
p. 449 - 455
(2009/07/10)
-
- PROCESSES FOR SEPARATION OF FLUOROOLEFINS FROM HYDROGEN FLUORIDE BY AZEOTROPIC DISTILLATION
-
The present disclosure relates to a process for separating a fluoroolefin from a mixture comprising hydrogen fluoride and fluoroolefin, comprising azeotropic distillation both with and without an entrainer. In particular are disclosed processes for separating any of HFC-1225ye, HFC-1234ze, HFC-1234yf or HFC-1243zf from HF.
- -
-
Page/Page column 24-25
(2008/06/13)
-
- PROCESS FOR THE SYNTHESIS AND SEPARATION OF HYDROFLUOROOLEFINS
-
A process for the synthesis of fluorinated olefins of the formula CF3CF=CHX, wherein X is F or H comprising contacting hexafluoropropene with hydrogen chloride in the vapor phase, in the presence of a catalyst, at a temperature in the range from about 200 °C to about 350 °C, wherein the mole ratio of hydrogen chloride to hexafluoropropene is from about 2:1 to about 4:1, separating the 1-chloro-1,2,3,3,3-pentafluoro-1-propene, 1,1-dichloro-2,3,3,3-tetrafluoro-1-propene and hydrogen fluoride products from unreacted hexafluoropropene, and hydrogen chloride by distillation, hydrogenating either the 1-chloro-1,2,3,3,3-pentafluoro-1-propene, 1,1-dichloro-2,3,3,3-tetrafluoro-1-propene or mixture thereof over a catalyst, and dehydrochlorinating the said hydrogenation product to produce either 1225ye or 1234yf.
- -
-
Page/Page column 15-17
(2008/12/07)
-
- PYROLYSIS PROCESS
-
The present invention relates to the pyrolysis of hydrochlorofluorocarbons to form fluoromonomers such as tetrafluoroethylene, the pyrolysis being carried out in a reaction zone lined with nickel and mechanically supported by a jacket of other corrosion resistant metal, the nickel lining providing an improved yield of valuable reaction products.
- -
-
Page/Page column 4-5
(2008/06/13)
-
- PROCESS FOR THE PREPARATION OF 1,1,1,3,3,3-HEXAFLUOROPROPANE AND AT LEAST ONE OF 1,1,1,2,3,3-HEXAFLUOROPROPANE AND 1,1,1,2,3,3,3-HEPTAFLUOROPROPANE
-
A process is disclosed for the manufacture of 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) and at least one 1,1,1,2,3,3-hexafluoropropane (HFC-236ea) and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea). The process involves (a) reacting HF, Cl2, and at least one halopropene of the formula CX3CCl=CX2 (where each X is independently F or Cl) to produce a product including both CF3CCl2CF3 and CF3CClFCClF2; (b) reacting CF3CCl2CF3 and CF3CClFCClF2 produced in (a) with hydrogen to produce a product comprising CF3CH2CF3 and at least one compound selected from the group consisting of CHF2CHFCF3, and CF3CHFCF3; and (c) recovering from the product produced in (b), CF3CH2CF3 and at least one compound selected from the group consisting of CHF2CHFCF3 and CF3CHFCF3. In (a), the CF3CCl2CF3 and CF3CClFCClF2 are produced in the presence of a chlorofluorination catalyst including a ZnCr2O4/crystalline α-chromium oxide composition, a ZnCr2O4/crystalline α-chromium oxide composition which has been treated with a fluorinating agent, a zinc halide/α-chromium oxide composition and/or a zinc halide/α-chromium oxide composition which has been treated with a fluorinating agent.
- -
-
Page/Page column 16; 19
(2008/06/13)
-
- Systems and methods for producing fluorocarbons
-
Systems and methods for producing fluorocarbons are provided that include contacting a saturated halogenated fluorocarbon with hydrogen and catalyst to produce a saturated hydrofluorocarbon and an unsaturated fluorocarbon. Aspects of the present invention describe systems and methods for contacting saturated halogenated fluorocarbons such as CF3CClFCF3 and/or CF3CCl2CF3 with hydrogen and catalyst. Systems and methods of the present invention also describe contacting saturated halogenated fluorocarbons with catalysts having one or more of K, Zr, Na, Ni, Cu, Ni, Zn, Fe, Mn, Co, Ti, and Pd. Aspects of the present invention also describe contacting saturated halogenated fluorocarbons with hydrogen under pressure. Saturated hydroflourocarbons and unsaturated fluorocarbons produced in accordance with the systems and methods of the present invention can include one or more of CF3CFHCF3, CF3CH2CF3, CF3CHClCF3, CF3CF═CF2, CF3CH═CF2, and CF3CCl═CF2.
- -
-
Page/Page column 3-14
(2008/06/13)
-
- Insertion reactions of difluorocarbene generated by pyrolysis of hexafluoropropene oxide to O-H bond
-
ROCHF2-type fluorinated ethers were synthesized by the reaction of hexafluoropropene oxide (HFPO) with alcohol or phenol. In this reaction, although the insertion reaction of difluorocarbene to OH bond and the nucleophilic attack of alcohol or
- Mizukado, Junji,Matsukawa, Yasuhisa,Quan, Heng-Dao,Tamura, Masanori,Sekiya, Akira
-
p. 373 - 377
(2007/10/03)
-
- Synthesis of hexafluoropropylene
-
The present invention relates to the process of pyrolyzing tetrafluoroethylene to hexafluoropropylene by carrying out the pyrolysis in a tubular reactor that is lined with either nickel or nickel alloy which contains no greater than 8 wt % chromium.
- -
-
-
- PROCESS FOR PRODUCING FLUOROMONOMER
-
Processes for producing a fluoromonomer from a fluoropolymer, among which one that can be carried out more simply is a process wherein thermal decomposition of a fluoropolymer is preformed by means of a rotary kiln (5) so as to produce a fluoromonomer, the process comprising feeding a fluoropolymer and steam (3) into a rotary kiln and heating the fluoropolymer.
- -
-
-
- METHOD OF A SIMULTANEOUS PREPARATION OF HEXAFLUOROPROPYLENE AND OCTAFLUOROCYCLOBUTANE
-
A method of simultaneous and selective perpararation of hexafluoropropylene and octafluorocyclebutane comprising the steps of: (a) thermally decomposing difluorochloromethane to obtain tetrafluoroethylene and then supplying the resulting tetrafluoroethylene into a bed reactor equipped with a distributor for supplying steam; and (b) supplying steam into a flow of tetrafluoroethylene supplied into the fluidized bed reactor, through a distributor for supplying steam at a certain molar ratio of tetrafluoroethylene/stream, and then performing dimerization of tetrafluoroethylene in the fluidized bed reactor under an atmospheric pressure.
- -
-
-
- Simultaneous preparation of tetrafluoroethylene and hexafluoropropylene
-
The present invention relates to a process for simultaneously preparing tetrafluoroethylene and hexafluoropropylene by the pyrolysis of difluorochloromethane mixed in the molar ratio of super-heated steam/pre-heated difluorochloromethane ([H2O]/[R22]) of 5-10 under the conditions such as a temperature of 730° C. to 760° C. and a residence time of 0.01 to 0.2 seconds, where the unreacted R22 and produced HFP are recycled and controlled to have an appropriate molar ratio of HFP/R22 of 0.01 to 0.1 in order to obtain a high yield of HFP. Thus, the pyrolysis process of the present invention is efficient for preparing TFE and HFP, which are essential monomers in fluorinated resin industry.
- -
-
-
- Processes for the purification and use of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane and zeotropes thereof with HF
-
A process is disclosed for the separation of a mixture of HF and CF3CClFCF3. The process involves placing the mixture in a separation zone at a temperature of from about ?30° C. to about 100° C. and at a pressure sufficient to maintain the mixture in the liquid phase, whereby an organic-enriched phase comprising less than 50 mole percent HF is formed as the bottom layer and an HF-enriched phase comprising more than 90 mole percent HF is formed as the top layer. The organic-enriched phase can be withdrawn from the bottom of the separation zone and subjected to distillation in a distillation column to recover essentially pure CF3CClFCF3. The distillate comprising HF and CF3CClFCF3can be removed from the top of the distillation column while essentially pure CF3CClFCF3can be recovered from the bottom of the distillation column. The HF-enriched phase can be withdrawn from the top of the separation zone and subjected to distillation in a distillation column. The distillate comprising HF and CF3CClFCF3can be removed from the top of the distillation column while essentially pure HF can be recovered from the bottom of the distillation column. If desired, the two distillates can be recycled to the separation zone. Also disclosed are compositions of hydrogen fluoride in combination with an effective amount of CF3CClFCF3to form an azeotrope or azeotrope-like composition with hydrogen fluoride. Included are compositions containing from about 38.4 to 47.9 mole percent CF3CClFCF3. Also disclosed are processes for producing 1,1,1,2,3,3,3-heptafluoro-propane. One process uses a mixture comprising HF and CF3CClFCF3and is characterized by preparing essentially pure CF3CClFCF3as indicated above, and reacting the CF3CClFCF3with hydrogen. Another process uses an azeotropic composition as described above, and reacts the CF3CClFCF3with hydrogen in the presence of HF. Also disclosed is a process for producing hexafluoropropene. This process is characterized by preparing essentially pure CF3CClFCF3as indicated above, and dehalogenating the CF3CClFCF3.
- -
-
Page column 7-8
(2008/06/13)
-
- 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.
- -
-
-
- The Reaction of 2-X-1,2-Difluoroalk-1-enyldifluoroboranes with Xenon Difluoride. A Methodical Approach to 1,2-Difluoroalk-1-enylxenon(II) Salts
-
2-X-1,2-Difluoroalk-1-enylxenon(II) salts were prepared by the reaction of XeF2 with XCF=CFBF2 (X = F, trans-H, cis-Cl, trans-Cl, cis-CF3, cis-C2F5) but no organoxenon(II) compounds were obtained when the trans-isomers of boranes, trans-XCF=CFBF 2 (X = CF3, C4F9, C 4H9, Et3Si), were used under similar conditions.
- Frohn, Hermann-Josef,Adonin, Nicolay Yu.,Bardin, Vadim V.
-
p. 2499 - 2508
(2008/10/09)
-
- An experimental and modelling study of ignition delays in shock-heated ethane-oxygen-argon mixtures inhibited by 2H-heptafluoropropane
-
Ignition delay times have been measured behind reflected shock waves in ethane-oxygenargon mixtures at temperatures between 1150 and 1500 K and pre-ignition pressures between 10 and 14 atm. Delay times have been measured both by pressure rise and OH absorption at 307 nm. Kinetic modelling of the ignition delays has been made using the GRIMech 3.0 mechanism which with addition of several reactions involving HO2 radicals and an increase in the barrier for reaction between C2H5 and O2 can satisfactorily model delays over the studied equivalence ratios of φ= 1.7 to 0.68. Addition of 2H-heptafluoropropane up to 13 mol % (of ethane) had little inhibition effect on stoichiometric ethane-oxygen-argon mixtures but inhibited ignition in a mixture of φ= 1.5. A kinetic mechanism is presented to model the inhibition process. by Oldenbourg Wissenschaftsverlag, Muenchen.
- Ikeda, Emi,Mackie, John C.
-
p. 997 - 1009
(2007/10/03)
-
- Halogenated hydrocarbons containing fluorine and processes for their manufacture
-
Processes are disclosed for producing hydrohaloolefins having the formula CF2=C(CH2RF)CF3, the formula FRCF=C(CH2RF)CF3 or the formula FRCF=C(CH2RF)(CF2RF) wherein each R is a difinctional group of the formula -C2F2XY- where X and Y are attached to the same carbon, each X is H, Br, Cl or F and each Y is F or CF3. The processes involve reacting (CF3)2C=CH2 or certain olefinic adducts thereof with a second olefm of the formula CF2=CXY in the liquid phase in the presence of a Lewis acid catalyst selected from the group consisting of antimony pentafluoride and aluminum chlorofluoride. Also disclosed is 1,1,2,2,-tetrafluoro-3,3-bistrifluoromethylcyclobutane and a process for its production which involves reacting (CF3)2C=CH2 with CF2=CF2 in the liquid phase in the presence of a Lewis acid catalyst selected from the group consisting of antimony pentafluoride and aluminum chlorofluoride. Also disclosed are olefins of the formula FRCF=C(CH2RF)CF3, FRCF=C(CH2RF)(CF2RF) or CF2=C(CH2R1F.)CF3 (R, X and Y are defined as above) wherein R1 is -C2F2X(CF3)- where X and (CF3) are attached to the same carbon or -C2F3X1- wherein X1 is H, Br or Cl.
- -
-
-
- Intermediates of thermal transformations of perfluoro-organic compounds. New spectral data and reactions
-
New completely fluorinated intermediates were identified from spectroscopic studies of thermal reactions of perfluoro-olefins, some carbocycles, and perfluoro-oxiranes in the gas phase. Detailed mechanisms of several complex reactions were established. For example, the mechanism of higher perfluoro-olefin synthesis from lower species under pyrolysis was established. Following this mechanism the first stage is the reversible reaction of biradicaloid formation which are isomeric to perfluoro-olefins. It was shown that biradicaloids are the primary intermediates in recombination of singlet completely fluorinated carbenes.
- Buravtsev, Nikolay N.,A. Kolbanovsky, Yuly
-
-
- Pyrolysis of octafluorocyclobutane - revisited
-
A high-pressure, high-temperature reactor unit was developed to test batch-wise inter-conversions of hydrocarbons. A major ambiguity characterizes this reactor, as it does all similar units that have been described, determination of the time-temperature profile for the reacting mixture. Here we report on a solution to this problem - use of a `chemical thermometer,' based on the kinetics of dissociation of C4F8. We propose a revised set of rate constants that permit calibration of the reactor operation.
- Bauer,Javanovic
-
p. 171 - 177
(2007/10/03)
-
- Transformations of F-Alkyl Iodides and Bromides Induced by Nickel(0) Carbonyl
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Adducts of primary F-alkyl iodides with nickel carbonyl are formed readily in donor solvents and pyrolyze at 100-150 °C to give olefinic coupling products in high yield. The mechanism proposed to account for the observed chemistry involves preferential α-elimination of fluorine with formation of a carbenoid species complex coordinated to nickel. Differences in reaction paths among several types of substrate halides are rationalized on the basis of polarization of the Ni-C bond in the adducts. Support for these proposals is provided by state-of-the-art calculations.
- Krespan, Carl G.,Dixon, David A.
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- Infrared multiphoton dissociation of two perfluorobutenes
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Photofragment translational spectroscopy was used to examine the infrared multiphoton dissociation of octafluoro-1-butene and octafluoro-2-butene. The predominant unimolecular reaction in octafluoro-1-butene at moderate laser fluences is cleavage of a carbon-carbon single bond to give the products CF3 and C3F5. The two other reactions that take place are CF2 elimination and the formation of equal weight fragments with the chemical composition C2F4; both reactions take place via a diradical intermediate. Dissociation of octafluoro-1-butene to the resonance stabilized perfluoroallyl radical is suggested to account for the favoring of simple bond rupture. These three reaction pathways were also observed in octafluoro-2-butene dissociation, however, the branching fraction is different than from octafluoro-1-butene. In octafluoro-2-butene all three channels occur with roughly equal probability. The reactions involving CF2 loss and C2F4 formation in octafluoro-2-butene are thought to proceed through the same diradical intermediate as in octafluoro-1-butene, necessitating a 1,2-fluorine migration.
- Longfellow, Cheryl A.,Berrie, Cindy L.,Suits, Arthur G.,Lee, Yuan T.
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p. 7202 - 7208
(2007/10/03)
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- Electrophilic reactions of fluorocarbons under the action of aluminum chlorofluoride, a potent Lewis acid
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A new Lewis acid - aluminum chlorofluoride - was demonstrated to be an effective catalyst for the isomerisation of fluoroolefins, polyfluorinated epoxides and cyclopropanes.At ambient temperature this catalyst converts perfluorobutadiene-1,3 into perfluorobutyne-2 and perfluoro(4-methylpentene-2) into perfluoro(2-methylpentene-2) in nearly quantitative yield.At 100 deg C, aluminum chlorofluoride causes the cleavage of perfluorinated tertiary amines. - Keywords: Electrophilic reactions; Fluorocarbons; Aluminum chlorofluoride; Lewis acid; NMR spectroscopy
- Petrov, V. A.,Krespan, C. G.,Smart, B. E.
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p. 138 - 142
(2007/10/03)
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- Reductive dehalogenation of polyhalofluorocarbons with tributyltin hydride
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The reduction of polyhalofluorocarbons, including ClCF2CFClCF2Cl, (ClCF2CFCl)2, ICH2(CF2)3CH2I and vicinal dichloroperfluorocycloalkanes, with tributyltin hydride gave the corresponding hydrofluorocarbons in good to excellent yield.The results are compared with similar reductions with other reducing agents, and to tin hydride reductions of non-fluorinated analogs. - Keywords: Reductive dehalogenation; Polyfluorocarbons; Tributyltin hydride; NMR spectroscopy; Hydrofluorocarbons
- Puy, Michael Van Der,Belter, Randolph K.,Borowski, Ralph J.,Ellis, Lois A. S.,Persichini, Phillip J.,et al.
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- Labelling of the CFC-alternative, 2H-heptafluoropropane (HFC 227ea), with fluorine-18
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Various reactions of no-carrier-added K(+)-aminopolyether 2.2.2-fluoride were examined for labelling the CFC-alternative, 2H-heptafluoropropane (HFC 227ea), with the positron-emitting radioisotope, fluorine-18 (t1/2 = 109.7 min).Reaction with 2H-hexafluoroisopropyl tosylate incorporated less than 2percent of the radioactivity into HFC 227ea and about 12percent into three other volatile products.Reaction with hexafluoropropene led to a high incorporation of fluorine-18 (80percent) into four radioactive products, namely the desired HFC 227ea, hexafluoropropene, perfluoro-isohex-2-ene and an unknown, in a molar ratio of 5:4:38:3, respectively.Although reaction with 1-iodo-2H-hexafluoropropane gave HFC 227ea in a much higher radiochemical yield (50percent decay-corrected), the best radiochemical yield (80percent decay-corrected) was obtained by exchange with HFC 227ea.The mechanistic bases of the results are discussed.An efficient fully shielded and automated procedure was devised for labelling HFC 227ea with fluorine-18 in high radioactivity, based on the successful exchange reaction and GC purification. HFC 227ea was obtained in high radiochemical purity (>99percent) and high chemical purity (>98.4percent) at 80 min from the start of radiosynthesis.This product is suitable for studies of the disposition of HFC 227ea in vivo. - Keywords: 2H-Heptafluoropropane; HFC 227ea; Fluorine-18; Exchange labelling; Mass spectrometry; Reaction mechanisms
- Aigbirhio, Franklin I.,Pike, Victor W.
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- Optimized process for inert fluorinated silanes
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The present invention relates to an improved method for preparing a fluorinated silane having the formula or the formula said method comprising reacting the corresponding halide-functional or alkoxy-functional silane with lithium aluminum hydride or sodium borohydride to form a hydride-functional silane and then reacting the latter with a vinyl-terminated fluorotelomer or an allyl-terminated fluorotelomer, wherein at least three R1 of said silane (I), at least two of the R2 and at least one R4 of said silane (II) are selected from derivatives of fluorotelomers or fluorocotelomers, z has an average value of 0 to 4 and R3 is a derivative of an alkylene-terminated telechelic divalent telomer or cotelomer.
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- LASER-INDUCED DECOMPOSITION OF HEPTAFLUORO-2-IODOPROPANE
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CO2 laser-induced homogeneous decomposition of i-C3F7I yields a variety of perfluorinated compounds, which are suggested to be formed by recombinations of carbenes and radicals generated upon the cleavage of the C-1 bond and the fragmentation of the i-C3F7 radical.The decomposition of i-C3F7I in the presence of ethene leads mainly to the formation of (i-C3F7CH2)2 and i-C3F7(CH2)2I.
- Pola, Josef,Horak, Milan
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p. 121 - 124
(2007/10/02)
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- Tandem Nucleophilic Additions of Aryloxides
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Hydroquinone disodium salt added sequentially to tetrafluoroethylene and carbon dioxide to yield a symmetrical dicarboxylic acid, which was transformed into the corresponding dimethyl ester, diol, diamide, and diamine.Chlorotrifluoroethylene in analogous reactions gave the corresponding diester and diol in excellent yield.When this kind of transformation was attempted on phloroglucinol, the Kolbe-Schmitt carboxylation reaction intervened.Despite serious competition from addition/elimination processes under typical reaction conditions, the tandem addition of phenoxide ion to hexafluoropropene and carbon dioxide was carried out successfully at lower temperatures and higher carbon dioxide pressures.
- Arnold-Stanton, Regina,Lemal, David M.
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p. 151 - 157
(2007/10/02)
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- THERMOLYSIS AND UV-PHOTOLYSIS OF PERFLUORINATED IODO-ALKANES AND IODO-OXAALKANES: THERE IS A PREFERRED REACTION CHANNEL
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The thermal stability of perfluorinated iodides depends on their structure and decreases in the order of RFCF2CF2I>RFCF2CF(CF3)I>RFOCF(CF3)I=RFCF2C(CF3)2I.The major decomposition path consists of the elimination of an unsaturated compound (CF2=CF2, CF2=CF-CF3, O=CF-CF3, CF2=C(CF3)2, respectively) with concomitant formation of RFI.The highest selectivities were found for tertiary iodides and 2-iodo-3-oxaalkanes, whose decomposition is virtually irreversible.UV-photolysis of the iodo-compounds gave the same products as the thermolysis reactions.
- Probst, Anton,Werner, Konrad von
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p. 163 - 173
(2007/10/02)
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- THERMAL CONVERSIONS OF PERFLUOROMETHYLCYCLOPROPANE
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The thermal decomposition of perfluoromethylcyclopropane occurs selectively under homogeneous conditions at 600-740 K with the formation of perfluoropropylene and difluorocarbene, which dimerizes further to tetrafluoroethylene.
- German, L. S.,Grigor'ev, A. S.,Kolbanovskii, Yu. A.,Chepik, S. D.
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p. 311 - 312
(2007/10/02)
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- HALOGEN EXCHANGE EQUILIBRIA OF CHLOROFLUOROOLEFINS
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The thermochemical properties of the following reactions were determined using either AlF3 or Cr2O3 as catalysts: (1) (2) (3) In addition, the cis-trans equilibria of both CF3CF=CFCl and CF3CCl=CFCl were able to be derived from the reaction data.The experimental thermochemical properties for reactions (1), (2) and (3) were compared with property values calculated using a well-known approximation method.A study of the exchange equilibria of chlorofluoroethylenes failed to yield accurate thermochemical values due to significant side reactions.However, a brief study of the mechanism of a catalytic disproportionation of CF2=CFCl: was carried out.
- Coulson, D. Robert
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- Stabilization of tris(trifluoromethyl)borane in complexes with primary, secondary and tertiary amines. Crystal and molecular structure of (CF3)3B*NHEt2 and (CF3)3B*NH2Et
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Various adducts (CF3)3B*NHR1R2 of the unknown free Lewis acid tris(trifluoromethyl)borane with secondary amines have been prepared from Cl2BNR1R2 by nucleophilic trifluoromethylation with CF3Br/P(NEt2)3 and subs
- Brauer, D.J.,Buerger, H.,Doerrenbach, F.,Krumm, B.,Pawelke, G.,Weuter, W.
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p. 161 - 172
(2007/10/02)
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