593-53-3Relevant articles and documents
Deuterium kinetic isotope effects in the gas-phase SN2 reactions of solvated fluoride ions with methyl halides
Kato, Shuji,Hacaloglu, Jale,Davico, Gustavo E.,DePuy, Charles H.,Bierbaum, Veronica M.
, p. 9887 - 9891 (2004)
Rate constants and deuterium kinetic isotope effects (KIEs) are measured for gas-phase nucleophilic substitution (SN2) reactions of solvated fluoride ions of F-(methanol) + CH3X (X = Br, I), F -(isopropyl alcohol) + CH3I, and F-hydrogen fluoride) + CH3I at 300 K. The isotope effects are determined as the rate constant ratio kH/kD for specifically deuterated reactants, that is, methanol (CH3OH, CD3OH, CH 3OD, and CD3OD), isopropyl alcohol (i-C3H 7OH and i-C3H7OD), hydrogen fluoride (HF and DF), and methyl halides (CH3X and CD3X). The data reveal identical trends to those previously observed for F-(water) + CH 3X (O'Hair, R. A. J.; Davico, G. E.; Hacaloglu, J.; Dang, T. T.; DePuy, C. H.; Bierbaum, V. M. J. Am. Chem. Soc. 1994, 116, 3609). The S N2 reactivities decrease as reaction exothermicity decreases (CH 3I > CH3Br > CH3Cl) and as the nucleophile is solvated. Moderate inverse kinetic isotope effects (k H/kD N2 transition-state structure and bonding interactions analogous to those in the F -(H2O) + CH3X system.
A Theoretical Study of Fluorine Atom and Fluoride Ion Attack on Methane and Silane
Davis, Larry ,P.,Burggraf, Larry, W.,Gordon, Mark, S.,Baldridge, Kim, K.
, p. 4415 - 4419 (1985)
We have performed MNDO and ab initio calculations for reactions of fluorine atom attack on methane and silane and, in addition, fluoride ion attack on the same molecules in the case of MNDO.We modeled both substitution and abstraction reactions in each case.Results were compared with experimental data, where available.Comparisons show that MNDO usually does as well as the ab initio methods in reproducing experimental values for ΔE's of these reactions, but MNDO predicts activation barriers too high in most cases.Nevertheless, MNDO does qualitatively agree with the ab initio result that, while carbon undergoes abstraction much more easily than substitution, silicon can undergo either substitution or abstraction quite easily.The analysis in the case of fluoride ion attack on silane is complicated by the predicted ease of formation of a stable trigonal-bipyramidal intermediate.
Synthesis and characterization of tetramethylammonium trifluorosulfate
Hohenstein, Christian,Kadzimirsz, Daniel,Ludwig, Ralf,Kornath, Andreas
, p. 925 - 929 (2011)
[Me4N]+[SO2F3]-, the first example of a [SO2F3]- salt, has been prepared from Me4NF and SO2F2. The colorless, microcrystalline solid was characterized by its infrared and Raman spectra. The trigonal bipyramidal structure of C2v symmetry of the [SO 2F3]- anion is predicted by ab initio calculations. Two oxygen atoms with d(SO)=143.2pm and one fluorine atom with d(SF)=157.9pm occupy the equatorial plane. The two fluorine atoms in the axial position with d(SF)=168.5pm are repulsed by the two oxygen atoms forming a bent axis with (FaxSFax)=165.2°. Copyright
Rates of processes initiated by pulsed laser production of F atoms in the presence of HCl, CH4, and CF3H
Moore,Smith,Stewart
, p. 813 - 825 (1994)
Time-resolved vibrational chemiluminescence from HF has been recorded following the production of F atoms by the pulsed laser photolysis (λ = 266 nm) of F2 in the presence of HCl, CH4, and CF3H. In the first two cases, experiments have been conducted by observing emission from HF(ν = 3) at four temperatures from 295 to 139 K. Rate constants have been determined over this range of temperature for the reactions of F atoms with HCl and CH4 and of CH3 radicals with F2, and for the relaxation of HF(ν = 3) by HCl and CH4. The reaction of F atoms with CF3H is slower than those with HCl and CH4 and measurements on the emission from HF(ν = 2) have been used to infer rate constants for reaction and relaxation only at 295 K.
Observation of the Nucleophilic Displacement (SN2) Reaction F-+CH3Br→CH3F + Br- Induced by Dissociative Electron Capture in Binary van der Waals Clusters
Lehmann, Lars,Matejcik, Stefan,Illenberger, Eugen
, p. 287 - 290 (1997)
We report on the SN2 reaction F- + CH3Br→FCH3 + Br- in binary clusters composed of CH3Br and C2F6 in a crossed electron/molecular beam experiment. The reaction is induced by resonance dissociative electron attachment to the C2F6 component where the nucleophile F- is generated at an energy (around 3.8 eV) where CH3Br does not capture electrons to form Br-. The results indicate that the cross section for the SN2 reaction is independent of the total excess energy which can be varied between 1.7 and 5 eV in the present system. VCH Verlagsgesellschaft mbH 1997.
Kinetic Energy and Temperature Dependences for the Reaction of F(1-) with Halogenated Methanes: Experiment and Theory
Su, Timothy,Morris, Robert A.,Viggiano, A. A.,Paulson, John F.
, p. 8426 - 8430 (1990)
Rate constants have been measured as a function of average kinetic energy at several teperatures for the reaction of F(1-) with CH3Cl, CH3Br, and CH3I.The rate constants at low energy approach but are not equal to the collision limiting value.The rate constants for all three reactions decrease slowly with increasing average kinetic energy for enrgies below 0.2 to 0.3 eV.At 0.2 to 0.3 eV, a break occurs in the slopes of the energy dependence curves.Above these energies the rate constants decrease more rapidly with increasing energy.Trajectory calculations that include a probability function which is dependent upon collision angle were performed in order to examine the effects of orientation on the reactions.The calculations were fitted to the low energy portion of the experimental data.A more severe orientation requirement is found for the lighter halides.The energies at which the breaks occur in the experimental curves are reproduced by the calculations.These energies correspond to the energies at which the hard sphere collision diameter of the colliding partners is equal to the capture radius.
Temperature dependences of the rate constants and branching ratios for the reactions of F-(H2O)0-5 with CH3Br
Seeley, John V.,Morris, Robert A.,Viggiano
, p. 4598 - 4601 (1997)
The effects of solvation, isotopic substitution, and temperature on the reactions of F-(H2O)n=0-5 with CH3Br have been studied. The reaction of n = 0 produces Br- as the exclusive ionic product and has a rate which is fast, approaching the collision rate, with a slight negative temperature dependence of T-0.9±0.1. The reaction of n = 1 is a factor of 3 slower with a slightly larger negative temperature dependence, T-1.1±0.05. The main ionic product is Br-, with smaller amounts of Br-(H2O) also formed. Substituting D2O for H2O causes the n = 1 rate constant to increase slightly. The n = 2 reaction has a much slower rate and produces three ionic products: Br-, Br-(H2O), and F-(H2O)2(CH3Br). The n = 3 reaction is immeasurably slow. The rate constants for the n = 4 and 5 reactions are greater than those for the n = 3 reaction. The ionic products of these reactions are F-(H2O)3 and F-(H2O)4, respectively.
Photolysis of Fluorine Molecules Trapped in Solid Methane at 15 K: Evidence of the Reaction of Vibrationally Excited CH3F Molecules with F2
Misochko, E. Ya.,Benderskii, V. A.,Goldschleger, A. U.
, p. 13917 - 13920 (1995)
The kinetics of reactions initiated via F2 photolysis in solid methane at 15 K was studied with IR spectroscopy.CH3F...HF complexes, formed in a cage reaction with a quantum yield of 0.55 +/- 0.10, are the main products of the photolysis at a host:guest matrix ratio MIR > 5.At MIR 100 the formation of CH2F2 is also detected.Its quantum yield grows linearly with F2 concentration in the MIR range 100-13.The formation of CH2F2 is suggested to be due to the reaction of the F2 molecule with a highly vibrationally excited primary product CH3F*, formed upon photolysis of the reactant clusters (F2*CH4*F2).
A Very Strong Methylation Agent: [Me2Cl][Al(OTeF5)4]
H?mmerling, Sebastian,Thiele, Günther,Steinhauer, Simon,Beckers, Helmut,Müller, Carsten,Riedel, Sebastian
supporting information, p. 9807 - 9810 (2019/06/24)
A new chloronium-containing salt, [Me2Cl][Al(OTeF5)4], was synthesized on multigram scale by means of a simple one-pot procedure. The isolated product can be handled at room temperature and used as a strong electrophilic methylation agent. This is demonstrated by the methylation of the very weak bases P(CF3)3, PF3, MeI, and MeBr.
COMPOSITION INCLUDING FLUOROMETHANE AND METHOD FOR PRODUCING SAME
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Paragraph 0068-0070, (2018/06/04)
An object of the present invention is to provide a composition containing fluoromethane having high purity. A method for producing fluoromethane, comprising: pyrolyzing in a gas phase a fluorine-containing methyl ether represented by Formula (1): wherein R1 and R2 are the same or different, and each represents an optionally substituted linear or branched monovalent aliphatic hydrocarbon group, an optionally substituted monovalent aromatic hydrocarbon group, an optionally substituted monovalent cyclic aliphatic hydrocarbon group, hydrogen, or halogen, in the presence of an alumina catalyst to thereby obtain a mixed gas containing fluoromethane and acid fluoride, wherein: the alumina catalyst contains chlorine in an amount of 1.0 wt % or less.
