Effects of matrix polarity on the optical and electron spin resonance spectra of trapped electrons in organic glasses

1968 ◽  
Vol 72 (13) ◽  
pp. 4599-4603 ◽  
Author(s):  
Alfred Ekstrom ◽  
John E. Willard
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Trapped Electrons ◽  
Organic Glasses ◽  
Spin Resonance

Detection of trapped electrons in organic glasses after gamma irradiation at 4.2 °K by electron spin resonance spectroscopy

1967 ◽  
Vol 45 (22) ◽  
pp. 2723-2727 ◽  
Author(s):  
D. R. Smith ◽  
J. J. Pieroni
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Dipole Interaction ◽  
Necessary Condition ◽  
Resonance Spectroscopy ◽  
Hydrogen Atoms ◽  
Trapped Electrons ◽  
Organic Glasses ◽  
Spin Resonance ◽  
Gamma Irradiated

Several organic glasses which are known to form trapped electrons when gamma irradiated at 77 °K have been irradiated at 4.2 °K and examined by electron spin resonance (e.s.r.) at the same temperature. In each case an absorption is observed which is probably due to trapped electrons. In three cases, the yield of trapped electrons at 4.2 °K seems to be as great as at 77 °K. In one case, a glassy alkane, the yield is enhanced at 4.2 °K. Trapped electrons in ethanol give a narrower e.s.r. line at 4.2 °K than at 77 °K, suggesting less orientation in the solvent cage.Trapped hydrogen atoms are not detected after irradiation at 4.2 °K. Contrary to prediction, hydrogen atoms are also not detected after post-irradiation photolysis of the trapped electrons.The results suggest that electron traps exist prior to irradiation and that molecular orientation via electronic dipole interaction is not a necessary condition for electron trapping. The results do not distinguish between trapping in solvent defects or trapping via electron-induced polarization of molecular orbitals.

Ion radicals of styrene in irradiated organic glasses studied by electron spin resonance

1969 ◽  
Vol 1 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Takeo Iwamoto ◽  
Koichiro Hayashi ◽  
Seizo Okamura ◽  
Kanae Hayashi ◽  
Hiroshi Yoshida
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Organic Glasses ◽  
Spin Resonance

ELECTRON SPIN RESONANCE DETERMINATION OF THE RADIOLYTIC YIELDS OF TRAPPED ELECTRONS AND OTHER SPECIES IN AN ORGANIC GLASS

1965 ◽  
Vol 43 (8) ◽  
pp. 2141-2147 ◽  
Author(s):  
D. R. Smith ◽  
J. J. Pieroni
Keyword(s):  
Electron Spin Resonance ◽  
Liquid Nitrogen ◽  
Electron Spin ◽  
Liquid Nitrogen Temperature ◽  
Paramagnetic Species ◽  
Radical Ions ◽  
Trapped Electrons ◽  
Accuracy And Precision ◽  
Spin Resonance

The radiolytic yields, at liquid nitrogen temperature, of trapped electrons and radicals or radical-ions in 2-methyltetrahydrofuran and the yields of these species plus the biphenyl anion in solutions containing biphenyl have been determined by e.s.r. These measurements were also carried out after photolysis of the trapped electrons. The combined results are interpreted in terms of the identity of the intermediates and the reactions which they undergo. "Dual e.s.r. cavity" techniques have enabled greater accuracy and precision than is normally obtained when concentrations of paramagnetic species are determined by e.s.r.

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.

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