76-19-7Relevant academic research and scientific papers
Thermodynamically unstable fluorides of nickel: NiF4 and NiF3 syntheses and some properties
?emva,Lutar,Chacón,Fele-Beuermann,Allman,Shen,Bartlett
, p. 10025 - 10034 (1995)
F- acceptors (BF3, AsF5, SbF5, or BiF5) added to solutions of NiF62- salts in anhydrous hydrogen fluoride (aHF) below -65 °C precipitate the tan solid NiF4. This solid, preserved at ≤-65 °C, is quantitatively converted, by 2 equiv of F- donor (XeF6 or KF) in aHF, to dissolved NiF62-. Dry NiF4 loses F2 above -60 °C, the decomposition to nearly black NiF3 becoming rapid at ～0 °C. When the dry NiF4 is prepared from K2NiF6, inclusion of some K+ leads, on thermolysis at 0 °C, to a pyrochlore form of NiF3 (P-NiF3). P-NiF3 contains K+ in the open channels, with KxMiF3, x ≈ 0.1. The nearly cubic P-NiF3 unit cell is rhombohedral: a0 = 9.933(3) A?, α = 91.01(3)°, V = 980 A?3, z = 16, with absent reflections coincident with those of the cubic space group Oh7-Fd3m, appropriate for pyrochlore. Decomposition of NiF4 in aHF begins at -65 °C and is rapid at 0 °C, giving black rhombohedral NiF3 (A-NiF3) with a0 = 5.168(2) A?, α = 55.46(3) A°, V = 87.3 A?3, z = 2. When the NiF4 is made and decomposed at ～20 °C, with K+ present, a hexagonal tungsten bronze form of NiF3 is precipated (H-NiF3), with a0 = 7.074(6) A?, c0 = 7.193(6) A?, V = 312A?3, z = 6. R- and H-NiF3 can also be made by mixing solutions of Ni2+ salts [e.g., Ni(AsF6)2] with NiF62- salts (e.g. K2NiF6) in aHF. All forms of the trifluoride (R, H, and P) lose F2 on warming (R > 39°, H > 72° and P > 138 °C) to yield NiF2, but an intermediate red-brown phase is observed for R-NiF3. R-NiF3 at ～20 °C, oxidizes Xe to Xe(VI), perfluoropropene, C3F6, to perfluoropropane, C3F8, and solid LiCl with incandescence. H-NiF3 and P-NiF3 interact similarly but less energetically.
Decomposition characteristics of C5F10O/air mixture as substitutes for SF6 to reduce global warming
Li, Yi,Zhang, Xiaoxing,Xiao, Song,Chen, Qi,Wang, Dibo
, p. 65 - 72 (2018/02/14)
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.
Method for performing olefin addition reaction by using microchannel reactor
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Paragraph 0060; 0061; 0062; 0063; 0064, (2017/03/14)
The present invention discloses a method for carrying out addition on olefin and fluorine gas by using a microchannel reactor, wherein C2-C9 olefin or fluoroolefin reacts with F2 in a microchannel reaction module to obtain the corresponding fluoroalkane. According to the present invention, with the method, the purity of the prepared fluoroalkane is high, and the method has the cost advantage.
Preparation of trifluoroiodomethane via vapour-phase catalytic reaction between pentafluoroethane and iodine
Mao, Aiqin,Wang, Hua,Tan, Linhua,Nin, Xiangyang,Pan, Renming
, p. 4640 - 4642 (2013/07/19)
A new route for preparing C33I has been developed via a reaction between C2HF5 and I2. The influence of reaction temperature and active components of the catalysts on the amount of C33I was investigated. The result suggests that the selectivity of the C33I can be controlled by reaction conditions and active component of catalyst. The process for the formation of C33I and by-products is also discussed.
Catalytic pyrolysis of CHF3 over activated carbon and activated carbon supported potassium catalyst
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)
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.
Depolymerization of Fluoropolymers
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Page/Page column 4-5, (2009/06/27)
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.
Investigation of CF2 carbene on the surface of activated charcoal in the synthesis of trifluoroiodomethane via vapor-phase catalytic reaction
Yang, Guang-Cheng,Lei, Shi,Pan, Ren-Ming,Quan, Heng-Dao
experimental part, p. 231 - 235 (2009/08/07)
This paper investigates the synthetic mechanism of trifluoroiodomethane (CF3I) in the reaction of trifluoromethane and iodine via vapor-phase catalytic reaction. It is suggested that CF2 carbene is the key intermediate and is formed in the pyrolysis process of CHF3 at high temperature. However, in pyrolysis of CHF3 under activated charcoal (AC) existing conditions, no C2F4 was detected. H2 and 2-methyl-2-butene could not trap the CF2 carbene. When treating the remained compounds on the used AC with H2, CH4 is formed on the process. It is proposed that CF2 carbene combines with AC strongly and transfers into CF3 radical on heat. In addition, it is found that the AC is not only the catalyst supporter to form CF3I, but also a co-catalyst to promote the formation of CF2 carbene and CF3 radical.
PRODUCTION PROCESSES FOR MAKING 1,1,1,2,2,3-HEXAFLUOROPROPANE
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Page/Page column 12-13, (2008/06/13)
A process for making HFC-236cb is disclosed. The process comprises reacting TFE with HFC-32 in the presence of at least one co-product and a suitable catalyst to produce a product mixture comprising HFC-236cb, wherein the total amount of the at least one co-product is at least 10 ppmv based on the total amount of the tetrafluoroethylene, the difluoromethane and the at least one co-product.
CATALYTIC ADDITION OF HYDROFLUOROCARBONS TO FLUOROOLEFINS
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Page/Page column 7; 13-14, (2008/06/13)
A process is disclosed for making RR1R2CCR1R2F wherein R is selected from the group consisting of CH3, CH2F, C2H4F, and F(CF2)nCH2CH2 where n is an integer from 1 to 10, each R1 is independently selected from the group consisting of H, Cl, F and CF3, and each R2 is independently selected from the group consisting of H, F and CF3. The process involves reacting RF with R1R2C=CR1R2 in the presence of SbF5 to produce a product mixture comprising RR1R2CCR1R2F, wherein the reaction temperature is from about -60° C to about -10° C, provided that total number of carbon atoms in R1R2C=CR1R2 is 5 or less.
Synthesis of perfluoroalkanes in high-temperature fluorination of graphite with fluorine in a reactor with a free-falling graphite bed
Shelopin,Pashkevich,Alekseev,Mukhortov,Petrov,Asovich
, p. 1031 - 1034 (2008/02/05)
Reaction between fluorine and graphite in a reactor with a free-falling bed of graphite was studied in relation to the temperature in the reaction zone, ratio of the feeding rates of fluorine and graphite, and dilution of fluorine with an inert gas. Pleiades Publishing, Inc., 2006.
