392-56-3Relevant articles and documents
Temperature-enhanced electron detachment from C6F6- negative ions
Datskos, P. G.,Christophorou, L. G.,Carter, J. G.
, p. 7875 - 7882 (1993)
A method is described whereby photoelectrons generated by a short laser pulse at the cathode of a parallel-plate electrode arrangement are depleted by attachment to C6F6 molecules mixed with N2 in the interelectrode space as they drift to the anode under an externally applied electric field.The contribution of the initially produced (prompt) and the delayed (autodetached from C6F6-) electrons to the induced signal in the detector circuit is recorded as a function of time following the laser pulse and also as a function of gas number density, applied electric field, and gas temperature, T.Increases in T from ambient to 575 K enhance dramatically the autodetachment frequency, τd-1, for C6F6-.This heat-activated autodetachment correlates with the increase in the internal energy of the anion and has an activation energy of 0.477 eV.Electron attachment producing C6F6- initially increases slightly with increasing T below 500 K and subsequently decreases with further increases in T.
Perfluorobarrelene
Ralli, Philip,Zhang, Yin,Lemal, David M.
, p. 7349 - 7351 (2008)
The title fluorocarbon has been synthesized in three steps from cis-5,6-dichlorohexafluorocyclohexa-1,3-diene, a hexafluorobenzene synthon. Photolysis of perfluorobarrelene yields perfluorocyclooctatetraene. An extremely facile retro-Diels-Alder reaction is also described.
Progress toward an absolute gas-phase proton affinity scale
Szulejko,McMahon
, p. 7839 - 7848 (1993)
The temperature dependence of the proton transfer equilibrium constants for approximately 80 pairs of bases ranging in proton affinity from N2 to tert-butylamine has been examined. These data provide the basis for formulation of a revised gas-phase proton affinity scale which now appears to have a firm basis. Excellent agreement with appearance energy determinations of proton affinities as well as ab initio calculated values is obtained. An important finding of this work is that the value of ΔHfo for the tert-butyl cation must be significantly higher than that derived from appearance energy measurements by Traeger which had formed the basis for the proton affinity assignment for isobutene, an important reference point in the proton affinity scale. The data obtained here would suggest that the proton affinity of isobutene must be revised downward by Δ4 kcal mol-1 with important consequence for all proton affinities in the vicinity of isobutene and above. In addition significant revisions are indicated for proton affinities between those of propene and isobutene. In contrast, however, the substantial upward revision of the proton affinity scale in the basicity region above ammonia which had been proposed by Mautner and Sieck (J. Am. Chem. Soc. 1991, 113, 4448) is not supported by the present experiments.
Ion-pair formation in the collision of high Rydberg argon atoms with SF6 and C6F6 and negative ion lifetimes
Dimicoli, I.,Botter, R.
, p. 2355 - 2360 (1981)
The ion-pair formation in collision between argon atoms in high Rydberg states (HR) with SF6 and C6F6 has been investigated.The absolute cross sections are inversely proportional to the Ar(HR) velocity and increase monotonically with increasing principal quantum number n.Measurements of the negative ion lifetimes against autodetachment are reported and are above 20μsec for SF6- and ca 1μsec and above 20 μsec for C6F6-.The present data are reviewed in light of the theoretical predictions of "free electron" models and the results of free electron experiments.
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Richardson,T.J.,Bartlett,N.
, p. 427 - 428 (1974)
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ELECTROPOLYMERISATION OF PERFLUOROCYCLO-ALKENES.
Briscoe, Mark W.,Chambers, Richard D.,Silvester, Michael J.
, p. 1295 - 1298 (1988)
Novel conducting materials are obtained by cathodic electropolymerisation of perfluoro-cyclobutene and -cyclopentene.
Laser-Induced Fluorescence Studies of Large and Small Molecular Cations Produced by Using Electron Bombardment in a Free Jet Expansion
Lester, Marsha Isack,Zegarski, B. R.,Miller, Terry A.
, p. 5228 - 5233 (1983)
Laser-induced fluorescence (LIF) excitation spectra have been obtained for a number of ions produced by electron impact in a free jet expansion.The ions observed include N2+, CO2+, C6F6+, C6F5H+, C6F3H3+, and C4H2+.In all cases "cold" laser excitation spectra have been obtained.For the simpler ions information about rotational distributions is available, while for the large ions the elimination of hot bands, sequence congestion, extensive rotational contours, etc., makes their spectra much easier to interpret.Under certain circumstances Penning ionization in the expansion effectively competes with direct ionization via electron impact.Some satellite structure is obtained in the C6F6+ spectrum which may be ascribed to C6F6+.Ar.
Stabilities and Structures of C6F6-(C6F6) and C6F6+(C6F6)
Hiraoka, Kenzo,Mizuse, Susumu,Yamabe, Shinichi
, p. 3689 - 3694 (1990)
The equilibria of clustering reactions C6F6+/- + C6F6 = C6F6+/-(C6F6) were studied with a pulsed electron beam high-pressure mass spectrometer.Thermochemical stabilities of the clusters C6F6-(C6F6) and C6F6+(C6F6) were determined.It was found that the bond energy of C6F6-(C6F6) is larger than that of C6F6+(C6F6).While C6F6+(C6F6) has the site-to-site type geometry, C6F6-(C6F6) has a stack form according to the ab initio MO calculation.
Preparation method of hexafluorobenzene
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Paragraph 0024-0031, (2018/05/16)
The invention relates to a preparation method of hexafluorobenzene, and belongs to the field of chemical production techniques. The preparation method of the hexafluorobenzene is characterized by comprising the following technologies: (1) mixing potassium fluoride with a nonprotic polar solvent, thus obtaining a mixed solution; (2) adding a reaction substrate, nitrobenzene and a phase transfer catalyst in the mixed solution, thus obtaining a reaction system, wherein the reaction substrate is chloropentafluorobenzene; (3) putting the reaction system obtained in the step (2) in a high-pressure kettle, sealing after discharging air in the high-pressure kettle, and reacting, thus obtaining a product; (4) rectifying the product after distilling, thus obtaining the hexafluorobenzene. According to the method disclosed by the invention, the energy consumption is lower, side effects are few, the reaction steps are simple, and the operation is easy; the solvent denaturation amount is less, separation and recycling are easy, and compared with other methods, and the method is greener and more environmental friendly.
Interaction of the electrophilic bis(pentafluorophenyl)iodonium cation [(C6F5)2I]+ with the ambident pseudohalogenide anions [SCN]- and [CN]-
Hirschberg, Markus E.,Barthen, Peter,Frohn, Hermann-Josef,Bl?ser, Dieter,Tobey, Briac,Jansen, Georg
, p. 28 - 33 (2014/05/20)
The iodonium pseudohalide compounds, [(C6F5) 2I][X] (X = SCN and CN) were synthesized by means of fluoride substitution in [(C6F5)2I][F] with the Lewis acidic reagents (CH3)3Si-NCS and (CH3) 3Si-CN. The isolated iodonium pseudohalides are intrinsically unstable solids. Decomposition resulted in equimolar amounts of C 6F5I and C6F5SCN or C 6F5I and C6F5CN, respectively. In case of [(C6F5)2I][SCN] single crystals could be grown from CH2Cl2. The crystal structure revealed a dimer with an eight membered ring formed by two ambident anions bridging the iodine atoms of two cations by N and S coordination. The favored dimerization of [(C6F5)2I][SCN] and [(C6F 5)2I][CN] in the gas phase is supported by ab initio computations.
