71-43-2Relevant articles and documents
Tausz,v. Putnoky
, p. 1579 (1919)
Spokes,Gaydon
, p. 1114 (1957)
Glarium,Kraus
, p. 5398,5400 (1950)
Connor et al.
, p. 152 (1955)
Pyrolysis of Styrene. Kinetics and Mechanism of the Equilibrium Styrene Benzene + Acetylene
Grela, M. A.,Amorebieta, V. T.,Colussi, A. J.
, p. 9861 - 9865 (1992)
The thermal unimolecular decomposition of styrene into benzene and acetylene, C6H5CH=CH2 -> C6H6 + HCCH (1), was investigated in a low pressure (ca. 10 mTorr) flow reactor by on-line mass spectrometry between 1180 and 1350 K.Measured rates can be calculated, via RRKM extrapolation, from the expression log (K1, s-1) = 14.38 - 17076/T, which was derived by detailed balance from high-pressure (ca. 50 Torr) low-temperature (878-973 K) kinetic data for the reverse reaction.This value of E1 = 77.9 kcal/mol allows for the generation of vinylidene, H2C=C:; the carbene isomer of acetylene, as a primary product of the title reaction.A non-radical process involving the rate-determining extrusion of H2C=C: from a -7-methylene cyclohepta-2,4-diene intermediate in equilibrium with styrene is consistent with kinetic and thermochemical considerations.
Kinetic Parameters for the Unimolecular Dissociation of Styrene Ion
Dunbar, Robert C.
, p. 3283 - 3286 (1990)
Time-resolved photodissociation measurements of the laser-induced fragmentation of styrene molecular ion have been carried out at 355 nm.Taking thermal energy content into account, a unimolecular dissociation rate of 6.3 * 103 s-1 at an internal energy of 3.66 eV was derived.The new measurement has been combined with previous data from photodissociation and photoionization to give a dissociation rate-energy curve spanning 2 decades of rate values.By RRKM fitting to this curve, unimolecular kinetic parameters E0 = 2.43 +/- 0.05 eV and ΔS% (1000K) = -3.9 +/- 1 cal mol-1 K-1 were derived.The conclusion that this dissociation proceeds through a rate-limiting thight activated complex at E0 = 2.43 eV was affirmed.
Gaeumann,Rayroux
, p. 1563,1568 (1962)
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Komarewsky
, p. 264 (1957)
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Tuttler,Weissman
, p. 5342 (1958)
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Heffernon,Jones
, p. 120 (1966)
Kinetic Energy Release in Thermal Ion-Molecule Reactions: Single Charge-Transfer Reactions of V2+ and Ta2+ with Benzene
Gord, James R.,Freiser, Ben S.,Buckner, Steven W.
, p. 8274 - 8279 (1991)
Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) has been used to study the single charge-transfer reactions of V2+ and Ta2+ with benzene under thermal conditions.Thermal charge-transfer rate constants of 2.0 x 10-9 and 1.2 x 10-9 cm3 molecule-1s-1 were measured for V2+ and Ta2+, respectively.The total kinetic energy of the product ions was determined to be 1.91 +/- 0.50 eV for the V2+ case and 2.82 +/- 0.50 eV for the Ta2+ case.These results and a previous study of the Nb2+ - benzene single charge-transfer system suggest a simple long-distance electron-transfer mechanism proceeding by ionization of the 1a2u orbital of benzene with significant internal excitation of the nascent C6H6+ product.
Chemical nuclear polarization in the oxidation of phenylhydrazine by 1,4- benzoquinone or tetrachloro-1,4-benzoquinone
Levit,Kiprianova,Sterleva,Gragerov
, p. 313 - 316 (1976)
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Methane chemistry in the hot supersonic nozzle
Somorjai,Kim,Romm
, p. 7025 - 7030 (2001)
The combination of pyrolysis and expansion to a supersonic molecular beam was shown to be very effective in conversion of pure CH4 to heavier hydrocarbons. Pure CH4 conversion reached 70% when it reacted in a hot (1000°-1150°C) supersonic nozzle made of quartz with 100 μ dia orifice. Hydrogen, acetylene, benzene, methyl, and propargyl radicals were the major products in the distribution. CH4 conversion rate was not improved with the addition of O2, NO, or CO2 as O2 reacted primarily with surface carbon formed by CH4 decomposition. No oxygen containing hydrocarbon derivatives were observed. The lifetime of the nozzle was longer than pure CH4 as a reactant resulting from surface carbon removal by oxygen. The mechanism involved pyrolytic rather than catalytic surface generation of free hydrocarbon radicals with subsequent coupling to heavier hydrocarbon products prior to desorption to the gas phase and expansion to the supersonic beam.
Tedder,Vidaud
, p. 81 (1979)
Facile formation of benzene from a novel cyclohexane derivative
Liu, Xiadong,Zhang, Guangtao,Verkade, John G.
, p. 4449 - 4451 (2001)
Upon acidification, benzene forms at room temperature from the novel 1,3,5-cis-trisubstituted cyclohexane wherein the substituents are the azido phosphine cage moieties N3P(MeNCH2CH2)3N. The dominant reaction in the decomposition of this unusually thermally stable intermediate in the presence of HA is the formation of nitrogen and the salt [H2N=P(MeNCH2CH2)3N]A in addition to benzene. Evidence for a transannulated cage intermediate is presented.
Reaction of Hydrogen Atom with Benzene: Kinetics and Mechanism
Nicovich, J. M.,Ravishankara, A. R.
, p. 2534 - 2541 (1984)
The rate coefficients for the reactions H + C6H6 -> products (k1) (1), H + C6D6 -> products (k2) (2), D + C6H6 -> products (k3) (3), and D + C6D6 -> products (k4) (4) have been measured in the temperature range of 298-1000 K by using the pulsed photolysis-resonance fluorescence technique.On the basis of the obtained kinetic information, it is shown that the primary path in all these reactions is addition of the atom to the benzene ring form cyclohexadienyl radical.The rate coefficient for the thermal decomposition of the cyclohexadienyl radical has also been measured.When the rate coefficients for the formation and decomposition of the cyclohexadienyl radical are used, the standard heat of formation of cyclohexadienyl radical at 298 K is calculated to be 45.7 kcal/mol.The measured values of k1-k4 are compared with the results of previous investigations.Most of the observed kinetic behavior in these reactions has been explained on the basis of the addition-decomposition reaction scheme.
Thorp,Kamm
, p. 1022 (1914)
Wavelength-Specific Product Desorption as a Key to Raising Nitrile Yield of Primary Alcohol Ammoxidation over Illuminated Pd Nanoparticles
Han, Pengfei,Tang, Cheng,Sarina, Sarina,Waclawik, Eric R.,Du, Aijun,Bottle, Steven E.,Fang, Yanfen,Huang, Yingping,Li, Kun,Zhu, Huai-Yong
, p. 2280 - 2289 (2022/02/14)
Research on visible-light photocatalysts of metal nanoparticles (NPs) has focused on increasing the reactant conversion by light-excited charges (electrons and positively charged holes). However, light irradiation can accelerate catalysis by other mechanisms. Here, we report that 650 nm wavelength irradiation of 0.75 W·cm-2 significantly increases nitrile yield of ammoxidation of primary aromatic alcohols with an ammonium salt over supported Pd NPs at 80 °C in air. We found that the desorption of the nitrile product from the catalyst is the rate-determining step; the irradiation promotes not only alcohol oxidation and subsequent aldehyde cyanation over the Pd NPs but also the nitrile desorption selectively via resonance energy transfer to achieve a high nitrile yield. This new mechanism provides a knob for the exquisite control of catalytic reaction pathways for ecofriendly synthesis.
Synthesis of Decorated Carbon Structures with Encapsulated Components by Low-Voltage Electric Discharge Treatment
Bodrikov, I. V.,Pryakhina, V. I.,Titov, D. Yu.,Titov, E. Yu.,Vorotyntsev, A. V.
, p. 60 - 69 (2022/03/17)
Abstract: Polycondensation of complexes of chloromethanes with triphenylphosphine by the action of low-voltage electric discharges in the liquid phase gives nanosized solid products. The elemental composition involving the generation of element distribution maps (scanning electron microscopy–energy dispersive X?ray spectroscopy mapping) and the component composition (by direct evolved gas analysis–mass spectrometry) of the solid products have been studied. The elemental and component compositions of the result-ing structures vary widely depending on the chlorine content in the substrate and on the amount of triphenylphosphine taken. Thermal desorption analysis revealed abnormal behavior of HCl and benzene present in the solid products. In thermal desorption spectra, these components appear at an uncharacteristically high temperature. The observed anomaly in the behavior of HCl is due to HCl binding into a complex of the solid anion HCI-2 with triphenyl(chloromethyl)phosphonium chloride, which requires a relatively high temperature (up to 800 K) to decompose. The abnormal behavior of benzene is associated with its encapsulated state in nanostructures. The appearance of benzene begins at 650 K and continues up to temperatures above 1300?K.