Simultaneous electrochemical and electron spin resonance studies of the kinetics of the electroreduction of sulfur dioxide in nonaqueous media

1982 ◽  
Vol 86 (16) ◽  
pp. 3130-3134 ◽  
Author(s):  
F. C. Laman ◽  
C. L. Gardner ◽  
D. T. Fouchard

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.


1970 ◽  
Vol 48 (13) ◽  
pp. 1996-1999 ◽  
Author(s):  
J. T. Cooper

The electron spin resonance spectra of several substituted pyrene cations, produced by oxidation with boron trifluoride in sulfur dioxide, are reported. The spectra are analyzed and the splitting constants given. With 4-chloropyrene, hyperfine splitting is observed due to the chlorine atom, for the first time in such a species. Molecular orbital calculations (Hückel and McLachlan) are presented for three of the compounds studied.


1968 ◽  
Vol 72 (7) ◽  
pp. 2541-2547 ◽  
Author(s):  
Ryo Hirasawa ◽  
Takashi Mukaibo ◽  
Hideo Hasegawa ◽  
Noboru Odan ◽  
Tetsuo Maruyama

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