2154-56-5Relevant articles and documents
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Chilton,Porter
, p. 904 (1959)
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Dissociation Rate Constants of Alkylbenzenes from Hot Molecules Formed by 158-nm (F2 Laser) Irradiation
Shimada, Tetsuya,Ojima, Yuichi,Nakashima, Nobuaki,Izawa, Yasukazu,Yamanaka, Chiyoe
, p. 6298 - 6302 (1992)
Toluene, p-xylene, deuterated p-xylene, and mesitylene under low-pressure conditions as well as p-xylene under high-pressure conditions were studied with a 158-nm laser.Rise curves of the photoproducts were observed by the method of nanosecond laser photolysis.The ground-state alkylbenzenes with an internal energy of 8 eV are formed by internal conversion following the laser excitation.The alkylbenzenes dissociate to the corresponding benzyl-type and phenyl-type radicals via the hot molecule state.The dissociaton rate constants were 9.3 (+/- 0.7) x 107 s-1, 1.5 (+/- 0.3) x 107 s-1, 4.6 (+/- 0.4) x 106 s-1, and 3.0 (+/- 0.9) x 106 s-1, respectively.Dissociation rate constants of the C-H bond in the methyl group of the alkylbenzenes were estimated from these results and compared with previous predictions.
Kinetics and thermochemistry of the reaction of benzyl radical with O2: investigations by discharge flow/laser induced fluorescence between 393 and 433 K
Elmaimouni,Minetti,Sawerysyn,Devolder
, p. 399 - 413 (1993)
The kinetics of the reaction of the benzyl radical with molecular oxygen has been studied between 393 and 433 K. The Discharge Flow technique with detection of benzyl radicals by Laser Induced Fluorescence in their visible absorption band has been used. A
Shock tube determination of the overall rate of NH2 + NO → products in the thermal De-NOx temperature window
Song,Hanson,Bowman,Golden
, p. 715 - 721 (2001)
The rate coefficient of the reaction NH2 + NO → products (R1) was determined in shock tube experiments using frequency-modulation absorption spectroscopy for detection of NH2. Because of the sensitivity of the diagnostic system, very low reactant concentrations could be employed in order to reduce the influence of secondary reactions on the NH2 profiles. Benzylamine, C6H5CH2NH2, was used as a thermal source of the NH2 radicals in the experiments. To determine the reaction rate, a perturbation strategy was employed that is based on changes in the NH2 profiles when NO is added to the C6H5CH2NH2/Ar mixtures. The measured NH2 profiles were interpreted by detailed kinetic modeling to obtain the overall reaction rate of R1 in the temperature range 1262-1726 K. The lower temperature limit of the present study is in the middle of the Thermal De-NOx temperature window. The present rate measurements are consistent with both our previous determination of the rate at higher temperatures and lower temperature data. A rate expression obtained by combining our higher temperature data and lower temperature data is. k1 = 6.83 × 1015 T-1.203 e106/T(K) cm3 mol-1 s-1 for the temperature range 200-2500 K. The estimated uncertainty of the rate coefficient is ±20%.
Fluorescence from samarium(II) iodide and its electron transfer quenching: Dynamics of the reaction of benzyl radicals with Sm(II)
Skene,Scaiano,Cozens
, p. 7918 - 7921 (1996)
The luminescence from SmI2 in THF can be readily quenched by a variety of electron acceptors. In the case of organohalides, the reaction is quite fast; for example, for dichloromethane the rate constant is 2.7 × 108 M-1 s
The Formation of Gas Phase Benzyl Radicals during the Reaction of Toluene and Nitrous Oxide over Li-MgO and Sr-La2O3 Coupling Catalysts
Xu, Mingting,Lunsford, Jack H.
, p. 1203 - 1204 (1995)
Surface-generated gas-phase benzyl radicals have been detected during the reaction of toluene and nitrous oxide over Li-MgO and Sr-La2O3 catalysts.
Greatorex,Kemp
, p. 56,63 (1971)
Reaction of Arylmethanes and Heteroarylmethanes with the Nucleophilic Undecyl Radical
Mahiou, Belaid,Gleicher, Gerald Jay
, p. 2737 - 2741 (1989)
The relative rates of hydrogen atom abstraction from a series of 13 homoaryl- and heteroarylmethanes by the nucleophilic undecyl radical, thermally generated from lauroyl peroxide, were determined at 70 deg C.A reactivity range of 15 was obtained.Substant
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Jaquiss,Szwarc
, p. 312 (1952)
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Effect of medium on the rate constant of decarbonylation of phenylacetyl radical
Tsentalovich,Kurnysheva,Gritsan
, p. 237 - 240 (2001)
The rate constant kCO of decarbonylation of phenylacetyl radicals generated by photolysis of dibenzyl ketone was measured by laser flash photolysis technique in six solvents in a wide temperature range. The pre-exponential factors A and activation energies Ea of decarbonylation were found for all solvents. The kCO value decreases with an increase in the dielectric constant ε of the solvent, whereas an increase in the ability of the solvent for hydrogen bonding increases kCO. The results of quantum-chemical calculations confirm the mutual compensation of the contributions of specific and nonspecific solvations to the activation energy of decarbonylation in alcohols.
Collisional deactivation of vibrationally highly excited benzyl radicals
Damm,Deckert,Hippler
, p. 1901 - 1908 (1997)
The collisional deactivalion of vibrationally highly excited benzyl radicals in the ground electronic state has been investigated. Vibrationally excited benzyl radicals have been generated using the fast dissociation of vibrationally excited ethylbenzene prepared from UV absorption followed by fast internal conversion. Subsequent to complete collisional deactivation the benzyl radicals have been reexcited by the absorption of a further UV-photon also followed by fast internal conversion. Once again the collisional deactivation of the benzyl radicals has been monitored by time-resolved UV absorption spectroscopy. Average energies transferred per collision have been determined by comparison of absorption-time profiles with different initial vibrational energies. It was found that the rate of collisional deactivation of the open shell benzyl radical is almost identical to the rate of collisional deactivation of the closed shell hydrocarbons of similar size. WILEY-VCH Verlag GmbH, 1997.
EFFECT OF HIGH PRESSURE ON HYDROGEN ABSTRACTION BY THE CUMYLOXY RADICAL
Zhulin, V. M.,Rudakov, O. B.,Stashina, G. A.
, p. 1104 - 1107 (1985)
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Role of Ionic Processes in the Formation of Free Radicals in γ-Irradiated Glassy Toluene
Noda, Shoji,Ohi, Masami,Ershov, B. G.,Yoshida, Hiroshi
, p. 2210 - 2212 (1980)
Spectrophotometric study has been made on the reaction intermediates generated by γ-irradiation in glassy toluene at 77 K.Benzyl and methylcyclohexadienyl radicals are generated roughly in equal amounts, and the total yield (G value) of the radicals is 0.19.The addition of biphenyl results in the formation of biphenyl anion and cation and depletes the radical yield by 40 percent.The results indicate that the excited-state toluene, the precursor of the radicals, is generated by recombination of ions as well as by the direct effect of the radiation on toluene.
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Hein,Mesee
, p. 434,441, 445 (1943)
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A shock tube study of benzylamine decomposition: Overall rate coefficient and heat of formation of the benzyl radical
Song, Soonho,Golden, David M.,Hanson, Ronald K.,Bowman, Craig T.
, p. 6094 - 6098 (2002)
The decomposition rate of benzylamine (C6H5CH2NH2) and the heat of formation of the benzyl radical (C6H5-CH2) were determined in shock tube experiments combined with RRKM calcula
Spectroscopic evidence of α-methylbenzyl radical in the gas phase
Lee, Gi Woo,Ahn, Hyeon Geun,Kim, Tae Kyu,Lee, Sang Kuk
, p. 193 - 196 (2008)
We report the observation of the spectroscopic evidence of the α-methylbenzyl radical in a corona excited supersonic expansion using a pinhole-type glass nozzle for the first time. The precursors, toluene, ethylbenzene, and isopropylbenzene, seeded in a l
The photodissociation of toluene studied by forward photofragment translational spectroscopy
Froechtenicht, Ralf
, p. 4850 - 4859 (1995)
The translational energies of different fragments produced in laser induced unimolecular reactions are investigated in a molecular beam experiment.The time-of-flight of the photoproducts is measured in the forward direction with a mass specrometer.By operating the ion source at low electron impact energies it is possible to nearly eliminate fragmentation and observe the nascent products at their parent mass.With this technique the primary and secondary reaction channels can be identified and branching ratios and product translational energy distribution down to small kinetic energies can be measured.The method is illustrated in a study of the photodissociation of toluene (methylbenzene) at three excitation energies (Eex=51 590, 52 240, and 63 240 cm-1).From the measured product time-of-flight spectra the branching ratio as well as the translational energy distributions of the product molecules benzyl+H and phenyl+CH3 in the two reaction channels were determined.The measured product energy distributions are compared with RRK (Rice-Ramsperger-Kassel) and SACM (statistic adiabatic channel model) statistical theories.The experimental results agree very well with the SACM theory for the phenyl, but not for the benzyl products.This is attributed to a barrier in the exit channel for the latter product.
Paul,Fischer
, p. 1575,1584 (1973)
RELATIVE KINETICS OF THE RADICAL ADDITION OF BENZYL BROMIDE TO UNSATURATED COMPOUNDS
Terent'ev, A. B.,Gapusenko, S. I.,Vasil'eva, T. T.,Vitt, S. V.
, p. 1567 - 1571 (1992)
The relative rate constants of the addition of the C6H5CH2 radical to unsaturated compounds CH2=CHX (X = C4H9, SiMe3, CF3, CO2Me, CN) were determined under the conditions of initiation by the Fe(CO)5 + DMF system or by benzoyl peroxide.Depending on the values of the relative addition rate constants, the monomers can be arranged into the following series (X): CF3 ca.C4H9 SiMe3 CO2Me CN.The relatively nucleophilic character of the benzyl radical has been shown.It was found that under the initiation conditions by the Fe(CO)5 + DMF system, the addition stage proceeds by a free radical mechanism. Keywords: radical addition, relative kinetics, benzyl bromide, benzyl radical, unsaturated compounds, iron pentacarbonyl, dimethylformamide.
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Ikegami,Watanabe
, p. 1007,1008-1010 (1976)
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Femtosecond time-resolved photoelectron spectroscopy of the benzyl radical
R?der,Humeniuk,Giegerich,Fischer,Poisson,Mitri?
, p. 12365 - 12374 (2017/07/24)
We present a joint experimental and computational study of the nonradiative deactivation of the benzyl radical, C7H7, after UV excitation. Femtosecond time-resolved photoelectron imaging was applied to investigate the photodynamics of the radical. The experiments were accompanied by excited state dynamics simulations using surface hopping. Benzyl has been excited at 265 nm into the D-band (ππ?) and the dynamics was probed using probe wavelengths of 398 nm or 798 nm. At a probe wavelength of 398 nm a single time constant of around 70-80 fs was observed. When the dynamics was probed at 798 nm, a second time constant τ2 = 1.5 ps was visible, which can be attributed to further non-radiative deactivation to the lower-lying D1/D2 states.
Mesolysis Processes with Benzylic Carbon?Oxygen Bond Cleavage in Radical Anions of Aryl Benzyl Ethers Studied by Electron Pulse Radiolysis in DMF
Yamaji, Minoru,Tojo, Sachiko,Fujitsuka, Mamoru,Sugimoto, Akira,Majima, Tetsuro
, p. 798 - 803 (2016/08/02)
Based on transient absorption measurements obtained upon electron-pulse radiolysis of aromatic ethers in N,N-dimethylformamide (DMF), mesolysis processes of the radical anions were investigated. We observed transient absorption spectral change due to the
