Xn:Harmful;
116-15-4Relevant academic research and scientific papers
Nickel Fluorocarbene Metathesis with Fluoroalkenes
Harrison, Daniel J.,Daniels, Alex L.,Guan, Jia,Gabidullin, Bulat M.,Hall, Michael B.,Baker, R. Tom
, p. 5772 - 5776 (2018)
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.
Energetics of the Rearrangement of Neutral and Ionized Perfluorocyclopropane to Perfluoropropylene. Use of Infrared Multiphoton Dissociation Spectra To Identify Structural Isomers of Molecular Ions
Bomse, D. S.,Berman, D. Wayne,Beauchamp, J. L.
, p. 3967 - 3971 (1981)
Infrared photodissociation spectroscopy is used to compare the structure of gas-phase C3F6+ ions obtained by electron-impact ionization of two isomeric precursors: perfluoropropylene and perfluorocyclopropane.Photodissociation spectra are obtained by observing the extent of multiphoton dissociation as the CO2 laser is tuned across the 925-1080 cm-1 wavelength range.Ions are formed, stored, and detected with the use of techniques of ion cyclotron resonance spectroscopy.Infrared multiphoton exitation is effected by using low-power, continuous-wave laser radiation.The "fingerprint" spectrum of the molecular ion of pefluorocyclopropane is identical with that obtained from perfluoropropylidene, indicating rearrangement of the former to the latter.Photodissociation kinetics indicate that the entire perfluorocyclopropane molecular ion population isomerizes to the more stable perfluoropropylene structure.Thermochemistry of C3F6 and C3F6+ isomers is discussed.Comparisons are made with the analogous C3H6 system.Photoionization mass spectroscopy results yield ΔHf(c-C3F6) = -233.8 kcal/mol.
Perfluoroallyl Fluorosulphonate
Banks, Ronald E.,Birchall, J. Michael,Haszeldine, Robert N.,Nicholson, William J.
, p. 133 - 134 (1982)
Perfluoroallyl fluorosulphonate, procured via treatment of perfluoropropene with stabilized sulphur trioxide ('Sulfan'), reacts with potassium iodide, potassium bromide, sodium methoxide, and phenylmagnesium bromide to yield the corresponding perfluoroallyl derivatives CF2=CFCF2X, where X=I, Br, OMe, and Ph respectively.
Labelling of the CFC-alternative, 2H-heptafluoropropane (HFC 227ea), with fluorine-18
Aigbirhio, Franklin I.,Pike, Victor W.
, p. 67 - 74 (1995)
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
Decomposition of pentafluoroallyl fluorosulfate oxide
Lebedev,Berenblit,Troichanskaya,Gubanov
, p. 449 - 455 (2009)
Decomposition of pentafluoroallyl fluorosulfate oxide under nucleophilic catalysis is studied. The possible reaction mechanism is considered.
Perfluoroalkyl Grignard Reagents: NMR Study of 1-Heptafluoropropylmagnesium Chloride in Solution
Guang, Jie,Hopson, Russell,Williard, Paul G.,Fujiu, Motohiro,Negishi, Kazuyuki,Mikami, Koichi
, p. 5922 - 5928 (2016)
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.
Unimolecular rate constant and threshold energy for the HF elimination from chemically activated CF3CHFCF3
Duncan, Juliana R.,Roach, Michael S.,Stiles, Brooke Sibila,Holmes, Bert E.
, p. 6996 - 7002 (2010)
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.
Preparation of trifluoroiodomethane via vapor-phase catalytic reaction between hexafluoropropylene oxide and iodine
Yang, Guang-Cheng,Jia, Xiao-Qing,Pan, Ren-Ming,Quan, Heng-Dao
, p. 985 - 988 (2009)
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
Transformations of F-Alkyl Iodides and Bromides Induced by Nickel(0) Carbonyl
Krespan, Carl G.,Dixon, David A.
, p. 36 - 43 (1998)
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.
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)
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.
