Spin trapping of hydrogen atoms in .gamma.-irradiated liquid alkanes

1974 ◽  
Vol 78 (1) ◽  
pp. 91-92 ◽  
Author(s):  
S. W. Mao ◽  
Larry Kevan
Keyword(s):  
Spin Trapping ◽  
Hydrogen Atoms ◽  
Gamma Irradiated ◽  
Liquid Alkanes

Inorganic radicals of relevance to biological systems

1985 ◽  
Vol 311 (1152) ◽  
pp. 451-472 ◽  
Keyword(s):  
Redox Reactions ◽  
Biological Systems ◽  
Spin Trapping ◽  
Redox Cycle ◽  
Hydrogen Atoms ◽  
Solvated Electrons

There is little doubt that the most important inorganic radicals involved in biological systems are those which are intermediates in the oxygen-water redox cycle, i.e. OH’, O - 2 and HO’ 2' . Aspects of the structures and reactivities of these radicals are considered, together with methods of detection. In particular, the use of e.s.r. spectroscopy is outlined, including rapid-freeze and spin-trapping techniques. Attention is called to comparisons and contrasts between these radicals and corresponding sulphur-centred radicals, although these are not strictly ‘inorganic’. The oxygen-centred radicals are usually generated in vivo by redox reactions, but they are also of importance in radioly tic processes because they are formed from water. Other Radicals formed in this way whose structures and reactivities are considered include solvated electrons and hydrogen atoms.

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.

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