scholarly journals Electron spin resonance detection of radicals and electrons condensed from water vapor after irradiation with 1 MeV helium ions

1968 ◽  
Vol 46 (10) ◽  
pp. 1747-1754 ◽  
Author(s):  
W. A. Seddon ◽  
D. R. Smith ◽  
P. E. Bindner
Keyword(s):  
Electron Spin Resonance ◽  
Water Vapor ◽  
Electron Spin ◽  
Ion Beam ◽  
Physical Parameters ◽  
Hydrogen Atoms ◽  
Beam Experiment ◽  
Spin Resonance ◽  
Vapor Stream ◽  
Resonance Detection

A stream of water vapor was irradiated in a "crossed-beam" experiment by 1 MeV He+ ions. After traversing the He+ ion beam, the vapor was condensed on a quartz tube at 77°K. The deposit so formed was then isolated under vacuum and transferred to an electron spin resonance (e.s.r.) spectrometer. E.s.r. spectra were observed that arise from species formed as a consequence of radiolysis in the vapor phase. Species trapped in the deposit were identified as HO2 radicals and electrons. Addition of CH3I and N2O gives results which indicate that hydrogen atoms were also formed although they do not become trapped in the deposit.The physical parameters of the experiment have been measured or calculated. These include the pressure and velocity of molecules in the vapor stream, and the time between irradiation and deposition on the cold finger.

Electron spin resonance studies of radicals condensed from irradiated water vapor: reactions of the radicals

1969 ◽  
Vol 47 (12) ◽  
pp. 2149-2154 ◽  
Author(s):  
P. Wardman ◽  
W. A. Seddon
Keyword(s):  
Electron Spin Resonance ◽  
Water Vapor ◽  
Electron Spin ◽  
Radical Scavengers ◽  
Hydrogen Atoms ◽  
Flow Rates ◽  
Spectroscopic Assignment ◽  
Spin Resonance ◽  
Polycrystalline Ice ◽  
Chemical Evidence

Electrons and hydroperoxyl radicals are trapped in polycrystalline ice after irradiation of water vapor and rapid condensation to 77 °K. Using higher sample flow rates than in the earlier work of Seddon, Smith, and Bindner, the electron spin resonance spectra of the trapped electrons (et−) were obtained in both H2O and D2O ice with negligible interference from the underlying HO2• (DO2•) radicals. Addition of C(NO2)4, H2O2, (CH3)2SO, and O2 as radical scavengers confirmed the earlier prediction that reactions with the radicals do not occur in the vapor phase in this system. The results with C(NO2)4 and H2O2 also provided chemical evidence consistent with the spectroscopic assignment for HO2• (DO2•) radicals. Experiments with added isobutylene suggested that hydrogen atoms are formed (possibly in a post-irradiation reaction during condensation) and are also produced on photobleaching et− at 77 °K.

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.

scholarly journals Electron Spin Resonance Detection of Hydrogen Peroxide as an Endothelium-Derived Hyperpolarizing Factor in Porcine Coronary Microvessels

2003 ◽  
Vol 23 (7) ◽  
pp. 1224-1230 ◽  
Author(s):  
Tetsuya Matoba ◽  
Hiroaki Shimokawa ◽  
Keiko Morikawa ◽  
Hiroshi Kubota ◽  
Ikuko Kunihiro ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Spin Resonance ◽  
Resonance Detection

Electron Spin Resonance of DNA Irradiated with a Heavy-Ion Beam ( 16 O 8+ ): Evidence for Damage to the Deoxyribose Phosphate Backbone

1996 ◽  
Vol 146 (4) ◽  
pp. 361 ◽  
Author(s):  
David Becker ◽  
Yurii Razskazovskii ◽  
Michael U. Callaghan ◽  
Michael D. Sevilla
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Ion Beam ◽  
Heavy Ion ◽  
Phosphate Backbone ◽  
Spin Resonance ◽  
Heavy Ion Beam
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