Electron spin resonance studies of γ-irradiated aqueous alkaline solutions of acrylamide at 77 °K

1967 ◽  
Vol 45 (24) ◽  
pp. 3083-3088 ◽  
Author(s):  
W. A. Seddon ◽  
D. R. Smith
Keyword(s):  
Electron Spin Resonance ◽  
Concentration Dependence ◽  
Electron Spin ◽  
Radical Anion ◽  
Maximum Yield ◽  
Alkaline Solutions ◽  
Trapped Electrons ◽  
Spin Resonance

The γ radiolysis of acrylamide in 8 M NaOH solutions in H2O and D2O at 77 °K results in the formation of [Formula: see text]and [Formula: see text]radicals, with a maximum yield [Formula: see text] = 1.9 molecules/100 eV. Since in the absence of acrylamide the yield of trapped electrons, G0(e−t), = 1.9, it appears that the precursor of [Formula: see text] is a radical anion [Formula: see text], which then abstracts a proton from the solvent according to [Formula: see text]In support of this interpretation we find that Hm1· is also formed in similar media as a result of (a) "photo-bleaching" of trapped electrons or (b) photo-detachment of electrons from ferrocyanide ion with light of wavelength 2 537 Å. This is confirmed by the electron spin resonance (e.s.r.) spectra obtained from methacrylamide and acrylonitrile in γ-irradiated alkaline ice. The concentration dependence of electron scavenging by acrylamide indicates that the electrons diffuse over distances of up to 170 Å prior to trapping or capture by the solute.

The Electron Spin Resonance Spectra of the Photochemically Produced Perfluorobenzophenone Ketyl and Anion Radicals

1971 ◽  
Vol 49 (13) ◽  
pp. 2350-2352 ◽  
Author(s):  
F. P. Sargent ◽  
M. G. Bailey
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Radical Anion ◽  
Flow System ◽  
Alcoholic Solution ◽  
Coupling Constants ◽  
Alkaline Solutions ◽  
Photochemical Method ◽  
Spin Resonance ◽  
Fluorinated Radical

The electron spin resonance spectra of the ketyl and radical anion of perfluorobenzophenone were generated in alcoholic solution by means of a photochemical method. The radical anion was prepared in alkaline solutions by means of a flow system to prevent nucleophillic degradation of the perfluorobenzophenone prior to photolysis. A comparison is made of the fluorine nuclear hyperfme coupling constants to those reported for partially fluorinated radical anions.

Electron spin resonance detection of heterogeneous reactions of Pigment Red 122

1990 ◽  
Vol 68 (4) ◽  
pp. 640-643
Author(s):  
Mary Jane Walzak ◽  
John R. Harbour
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Radical Anion ◽  
Heterogeneous Reactions ◽  
Resonance Spectroscopy ◽  
G Factor ◽  
Spin Resonance ◽  
Two Component ◽  
Induced Signal ◽  
Resonance Detection

Electron spin resonance spectroscopy (ESR) has been used to investigate the electrochemical and photolytic behaviour of particulate C.I. Pigment Red 122. Heterogeneous electrochemical reduction and oxidation of the pigment resulted in different reversible ESR signals with the radical cation giving a signal of ΔHpp = 2.3 G and g-factor of 2.0033 and the radical anion giving ΔHpp = 3.2 G and g-factor 2.0039. On exposure to light the inherent ESR signal, which was determined to be a two-component signal, increased in intensity by a factor of 2.4 but did not change in linewidth or g-factor. This light-induced signal was reversible and decayed to initial levels in the dark. The mechanism of these reactions is discussed. Keywords: ESR, pigment, electrochemistry, photo effects.

Sign in / Sign up

Export Citation Format

Share Document