1630-77-9Relevant articles and documents
Gas-phase reaction of CCl2F2 (CFC-12) with methane.
Uddin, Md Azhar,Kennedy, Eric M,Dlugogorski, Bogdan Z
, p. 1189 - 1191 (2003)
Gas-phase reaction of CFC-12 (CCl2F2) with methane was carried out in a plug flow reactor over the temperature range of 873-1123 K. The major organic halocarbons formed during the reaction were C2F4, C2H2F2, CHClF2, CH3Cl, C3H2F6 and CCl3F. The formation of all products except C2H2F2 decreased with temperature, while the selectivity to C2H2F2 (difluoroethylene) increased with temperature and reached approximately 80% at 1123 K. Under these reaction conditions, methane acts as hydrogen and carbon source, resulting in the formation of an unsaturated C2 hydrofluorocarbon from two C1 precursors.
Selective Copper Complex-Catalyzed Hydrodefluorination of Fluoroalkenes and Allyl Fluorides: A Tale of Two Mechanisms
Andrella, Nicholas O.,Xu, Nancy,Gabidullin, Bulat M.,Ehm, Christian,Baker, R. Tom
, p. 11506 - 11521 (2019)
The transition to more economically friendly small-chain fluorinated groups is leading to a resurgence in the synthesis and reactivity of fluoroalkenes. One versatile method to obtain a variety of commercially relevant hydrofluoroalkenes involves the catalytic hydrodefluorination (HDF) of fluoroalkenes using silanes. In this work it is shown that copper hydride complexes of tertiary phosphorus ligands (L) can be tuned to achieve selective multiple HDF of fluoroalkenes. In one example, HDF of the hexafluoropropene dimer affords a single isomer of heptafluoro-2-methylpentene in which five fluorines have been selectively replaced with hydrogens. DFT computational studies suggest a distinct HDF mechanisms for L2CuH (bidentate or bulky monodentate phosphines) and L3CuH (small cone angle monodentate phosphines) catalysts, allowing for stereocontrol of the HDF of trifluoroethylene.
High-resolution FTIR study of the v2 fundamental of cis-CHF=CHF
Visinoni,Giorgianni,Baldan,Nivellini
, p. 4242 - 4246 (2001)
The high-resolution FTIR spectrum at room temperature of cis-1,2-difluoroethylene has been analyzed in the v2 fundamental region from 1670 to 1760 cm-1. This vibration of A1 symmetry, corresponding to the C=C stretching, gives rise to a strong b-type band approximately centered at 1719 cm-1. The rovibrational analysis led to the assignment of many transitions in the P, Q and R branches with J′ ≤ 70, Ka′ ≤ 30, Kc′ ≤ 69. From a simultaneous fit of the ground state combination differences coming from the present work and the previously analyzed v4 and v10 fundamentals, together with a few literature microwave data, a set of ground state parameters, including all the quartic and four new sextic centrifugal distortion coefficients, was derived. Using the Watson's A-reduction Hamiltonian in the Ir representation, from the final fit of about 3600 assigned transitions, accurate rovibrational constants for the upper state were obtained with a standard deviation of about 8 × 10-4 cm-1.
FLUOROOLEFIN PRODUCTION METHOD
-
Paragraph 0047-0049, (2021/03/13)
The present disclosure provides a method for producing fluoroolefin represented by formula (1): CX1X2═CX3X4, wherein X1, X2, X3, and X4 are the same or different, and represent a hydrogen atom or a fluorine atom, with high selectivity. Specifically, the present disclosure is a method for producing fluoroolefin represented by formula (1), wherein the method includes the step of performing dehydrofluorination by bringing a fluorocarbon represented by formula (2): CX1X2FCX3X4H, wherein X1, X2, X3, and X4 are as defined above, into contact with a base, and the dehydrofluorination step is performed in the liquid phase at a temperature of ?70° C. or higher to less than 120° C.
Organocatalytic C?F Bond Activation with Alanes
Jaeger, Alma D.,Ehm, Christian,Lentz, Dieter
supporting information, p. 6769 - 6777 (2018/04/02)
Hydrodefluorination reactions (HDF) of per- and polyfluorinated olefins and arenes by cheap aluminum alkyl hydrides in non-coordinating solvents can be catalyzed by O and N donors. TONs with respect to the organocatalysts of up to 87 have been observed. Depending on substrate and concentration, high selectivities can be achieved. For the prototypical hexafluoropropene, however, low selectivities are observed (E/Z≈2). DFT studies show that the preferred HDF mechanism for this substrate in the presence of donor solvents proceeds from the dimer Me4Al2(μ-H)2?THF by nucleophilic vinylic substitution (SNV)-like transition states with low selectivity and without formation of an intermediate, not via hydrometallation or σ-bond metathesis. In the absence of donor solvents, hydrometallation is preferred but this is associated with inaccessibly high activation barriers at low temperatures. Donor solvents activate the aluminum hydride bond, lower the barrier for HDF significantly, and switch the product preference from Z to E. The exact nature of the donor has only a minimal influence on the selectivity at low concentrations, as the donor is located far away from the active center in the transition states. The mechanism changes at higher donor concentrations and proceeds from Me2AlH?THF via SNV and formation of a stable intermediate, from which elimination is unselective, which results in a loss of selectivity.
