Arrhenius parameters for the reaction of propyl radicals with propane

1969 ◽  
Vol 47 (18) ◽  
pp. 3305-3311 ◽  
Author(s):  
R. E. Berkley ◽  
G. N. C. Woodall ◽  
O. P. Strausz ◽  
H. E. Gunning
Keyword(s):  
Hydrogen Atom ◽  
Thermodynamic Data ◽  
Reverse Reaction ◽  
Hydrogen Atom Abstraction ◽  
Arrhenius Parameters ◽  
Complicating Factors

The reaction of n-propyl radicals from the photolysis of azo-n-propane with propane has been studied and Arrhenius parameters for hydrogen atom abstraction relative to the recombination of n-propyl radicals determined. From the Arrhenius parameters obtained and the available thermodynamic data, the Arrhenius parameters of the reverse reaction, the hydrogen atom abstraction from propane by iso-propyl radicals, have been calculated.Some complicating factors in the photolysis of azopropane are discussed.

Reactions of trifluoromethyl radicals. I. Hydrogen abstraction from dimethyl sulphide

1972 ◽  
Vol 25 (4) ◽  
pp. 803 ◽  
Author(s):  
NL Arthur ◽  
KS Yeo
Keyword(s):  
Hydrogen Atom ◽  
Rate Constant ◽  
Hydrogen Abstraction ◽  
Reverse Reaction ◽  
Thermochemical Data ◽  
Hydrogen Atom Abstraction ◽  
Dimethyl Sulphide ◽  
Temperature Range

Hydrogen atom abstraction from (CH3)2S by CF3 radicals has been studied in the temperature range 79-167�: (1) CF3 + CH3SCH3 ←→ CF3H + CH3SCH2 (-1) The rate constant, based on Ayscough's value of 1013.36cmS mol-l s-l for the recombination of CF3 radicals, is given by (k1 in cm3 mol-1 s-l, E in J mol-l): Logk1 = (12.05 � 0.02)-(28710 � 130)/2.303RT Combination of these results with thermochemical data gives a calculated value of log k-1 = 12.2 - 62600/2.303RT for the rate constant of the reverse reaction. ΔH�f(CH3SCH2) and S�(CH3SCH2) are estimated to be 155.6 kJ mol-l and 290 J K-l mol-1 respectively.

2-Deoxyribose Radicals in the Gas Phase and Aqueous Solution. Transient Intermediates of Hydrogen Atom Abstraction from 2-Deoxyribofuranose

2005 ◽  
Vol 70 (11) ◽  
pp. 1769-1786 ◽  
Author(s):  
Luc A. Vannier ◽  
Chunxiang Yao ◽  
František Tureček
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Computational Study ◽  
Hydrogen Atom Abstraction ◽  
Oh Radical ◽  
Free Energies ◽  
Intramolecular Hydrogen ◽  
Solvation Free Energies ◽  
Transient Intermediates

A computational study at correlated levels of theory is reported to address the structures and energetics of transient radicals produced by hydrogen atom abstraction from C-1, C-2, C-3, C-4, C-5, O-1, O-3, and O-5 positions in 2-deoxyribofuranose in the gas phase and in aqueous solution. In general, the carbon-centered radicals are found to be thermodynamically and kinetically more stable than the oxygen-centered ones. The most stable gas-phase radical, 2-deoxyribofuranos-5-yl (5), is produced by H-atom abstraction from C-5 and stabilized by an intramolecular hydrogen bond between the O-5 hydroxy group and O-1. The order of radical stabilities is altered in aqueous solution due to different solvation free energies. These prefer conformers that lack intramolecular hydrogen bonds and expose O-H bonds to the solvent. Carbon-centered deoxyribose radicals can undergo competitive dissociations by loss of H atoms, OH radical, or by ring cleavages that all require threshold dissociation or transition state energies >100 kJ mol-1. This points to largely non-specific dissociations of 2-deoxyribose radicals when produced by exothermic hydrogen atom abstraction from the saccharide molecule. Oxygen-centered 2-deoxyribose radicals show only marginal thermodynamic and kinetic stability and are expected to readily fragment upon formation.

scholarly journals A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Huang ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Evolution ◽  
Alkyl Radical ◽  
Cobalt Catalyst ◽  
Alkylation Reaction ◽  
Hydrogen Atom Abstraction ◽  
Dehydrogenative Coupling ◽  
Radical Generation ◽  
Limited Scope

AbstractHydrogen atom abstraction (HAT) from C(sp3)–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report a photo-induced and chemical oxidant-free cross-dehydrogenative coupling (CDC) between alkanes and heteroarenes using catalytic chloride and cobalt catalyst. Couplings of strong C(sp3)–H bond-containing substrates and complex heteroarenes, have been achieved with satisfactory yields. This dual catalytic platform features the in situ engendered chlorine radical for alkyl radical generation and exploits the cobaloxime catalyst to enable the hydrogen evolution for catalytic turnover. The practical value of this protocol was demonstrated by the gram-scale synthesis of alkylated heteroarene with merely 3 equiv. alkane loading.

New Catalytic Radical Process Involving 1,4-Hydrogen Atom Abstraction: Asymmetric Construction of Cyclobutanones

2021 ◽  
Author(s):  
Jingjing Xie ◽  
Pan Xu ◽  
Yiling Zhu ◽  
Jingyi Wang ◽  
Wan-Chen Cindy Lee ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Atom Abstraction ◽  
Radical Process

ChemInform Abstract: Electron Transfer and Hydrogen Atom Abstraction Mechanism for 1-Benzyl- 1,4-dihydronicotinamide Reduction of Benzoquinones.

ChemInform ◽  
2010 ◽  
Vol 22 (17) ◽  
pp. no-no
Author(s):  
D. D. TANNER ◽  
A. KHARRAT ◽  
H. OUMAR-MAHAMAT
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Hydrogen Atom Abstraction

The photoinduced addition of acetone to 1,7-dimethyltricyclo[4.1.0.02,7]Heptane. Hydrogen atom abstraction from an activated methyl group

1984 ◽  
Vol 25 (29) ◽  
pp. 3051-3054 ◽  
Author(s):  
Paul G. Gassman ◽  
John L. Smith
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Atom Abstraction ◽  
Methyl Group

Absolute Rate Constants for Hydrocarbon Autoxidation. Part XX. Oxidation of Some Organic Sulfides

1971 ◽  
Vol 49 (12) ◽  
pp. 2178-2182 ◽  
Author(s):  
J. A. Howard ◽  
S. Korcek
Keyword(s):  
Liquid Phase ◽  
Hydrogen Atom ◽  
Rate Constants ◽  
Hydrogen Atom Abstraction ◽  
Absolute Rate ◽  
Organic Sulfides

Absolute rate constants for the liquid phase autoxidation of some organic sulfides at 30 °C have been measured. The reactivities of organic sulfides towards t-butylperoxy radicals are equal to or somewhat less than the reactivities of structurally analogous ethers. The α-alkylthiylalkylperoxy radicals appear to be about 3–5 times more reactive in hydrogen atom abstraction than the α-alkoxyalkylperoxy radicals.

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