Kinetics of the reactions of substituted benzoquinones with alkyl radicals

The electron spin resonance method was employed to study the nature, concentration and kinetics of the disappearance under varying conditions of radicals produced in polyethylene by fast electron irradiation at 77°K. The predominant radical species at 77°K is the alkyl radical —CH 2 —ĊH—CH 2 —. On being warmed to room temperature it disappears rapidly, revealing a more stable unidentified radical. The kinetics of the decay at room temperature of both radicals was observed. Their stabilities were found to vary in polyethylene samples of differing physical and chemical properties. G values for these radicals are given. Comparison was made with spectra obtained under similar conditions with two pure paraffins and a pure olefin to evaluate the effect of crystallinity branching, molecular weight and unsaturation. In the olefin there is evidence for a build-up of allyl radicals due to the encounter of an alkyl radical with main chain unsaturation. This supports the view that alkyl radicals are mobile, and cross-linking occurs when two such radicals meet.

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Kinetics of the reactions of alkyl radicals (CH3, C2H5, i-C3H7, and t-C4H9) with molecular bromine

The Journal of Physical Chemistry ◽

10.1021/j100370a050 ◽

1990 ◽

Vol 94 (7) ◽

pp. 3005-3008 ◽

Cited By ~ 21

Author(s):

R. S. Timonen ◽

J. A. Seetula ◽

D. Gutman

Keyword(s):

Molecular Bromine ◽

Alkyl Radicals ◽

Kinetics Of

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Kinetics of the reactions between alkyl radicals and molecular oxygen in aqueous solution

The Journal of Physical Chemistry ◽

10.1021/j100164a051 ◽

1991 ◽

Vol 95 (11) ◽

pp. 4440-4441 ◽

Cited By ~ 54

Author(s):

Adam Marchaj ◽

Douglas G. Kelley ◽

Andreja Bakac ◽

James H. Espenson

Keyword(s):

Aqueous Solution ◽

Molecular Oxygen ◽

Alkyl Radicals ◽

Kinetics Of

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The kinetics of the addition of alkyl radicals to carbonyl groups. II. The addition of methyl radicals to trifluoroacetone in the gas phase. The formation reaction of the trifluoro-t-butoxy radical

International Journal of Chemical Kinetics ◽

10.1002/kin.550161105 ◽

1984 ◽

Vol 16 (11) ◽

pp. 1327-1335 ◽

Cited By ~ 2

Author(s):

J. Alistair Kerr ◽

J. Paul Wright

Keyword(s):

Gas Phase ◽

Methyl Radicals ◽

Carbonyl Groups ◽

Formation Reaction ◽

Alkyl Radicals ◽

Butoxy Radical ◽

Kinetics Of

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Modulation spectroscopy. Kinetics for the self-reactions of some α-aminoalkyl radicals in solution

Canadian Journal of Chemistry ◽

10.1139/v82-041 ◽

1982 ◽

Vol 60 (3) ◽

pp. 274-278 ◽

Cited By ~ 9

Author(s):

Paul R. Marriott ◽

Arlindo L. Castelhano ◽

David Griller

Keyword(s):

Absorption Spectrum ◽

Reaction Kinetics ◽

Unpaired Electron ◽

Rate Constants ◽

Lone Pair ◽

The Self ◽

Modulation Spectroscopy ◽

Alkyl Radicals ◽

Diffusion Controlled ◽

Kinetics Of

The optical spectra and reaction kinetics of some a-aminoalkyl radicals, RĊHN(CH2R)2; R≡H, Me, Ph, were measured in solution using the technique of modulation spectroscopy. These radicals undergo diffusion controlled self-reaction with rate constants [Formula: see text]. When R≡Ph, the absorption spectrum has a well defined maximum at 346 nm; ε = 3390 M−1 cm−1, while the spectra when R≡H or Me were less intense [Formula: see text] and tailed into the visible. These spectra are substantially red-shifted when compared with those of simple alkyl radicals, an effect which is thought to be due to the interaction between the unpaired electron and the lone pair of electrons on nitrogen.

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