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Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements

Abstract

The electron spin resonance (E.S.R.) spectra of gamma irradiated polar organic glasses, at 77 K, shows a single line centered at g {approx} 2, attributed to solvated electrons. The radicals produced on scavenging this species by electron acceptors, such as aromatic hydrocarbons, nitro-compounds and azines have been studied by E.S.R. In most cases, the radicals from these solutes, the spectra of which are observed after elimination by warming of the radicals from the matrices, are produced by protonation of the anions formed by scavenging of electrons at 77 K. Thus, in the case of glassy solutions of nitro-compounds, the radicals R NO{sub 2}H are formed. They are characterized by a{sub N} = 15 G (nitrobenzene) or a{sub N} = 28 G (nitro-alkane). These radicals are also generated by U.V, photolysis at room temperature of solutions of nitro-compounds in alcohols and are shown to be the precursors of nitroxide radicals R - N - R (with N - O) observed simultaneously. Gamma irradiation of solutions of pyridine and of the three diazines, in alcohol glasses at 77 K, produces the radical formed by hydrogen addition to these compounds. The value of the coupling constant of the additional proton (7-10 G) indicates  More>>
Authors:
Chachaty, C [1] 
  1. Commissariat a l'Energie Atomique Saclay (France). Centre d'Etudes Nucleaires
Publication Date:
Jun 01, 1968
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-3537
Resource Relation:
Other Information: TH: These sciences physiques; 123 refs; PBD: Jun 1968
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; ALCOHOLS; ALKANES; ELECTRON SPECTRA; ELECTRON SPIN RESONANCE; EMISSION SPECTRA; GAMMA RADIATION; GLASS; NITROBENZENE; PARAMAGNETISM; PHOTOLYSIS; PYRAZINES; PYRIDINE; RADIOLYSIS
OSTI ID:
20523321
Research Organizations:
CEA Saclay, 91 - Gif-sur-Yvette (France); Paris-11 Univ., Faculte des Sciences, 91 - Orsay (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3537091376
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[110] pages
Announcement Date:

Citation Formats

Chachaty, C. Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements. France: N. p., 1968. Web.
Chachaty, C. Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements. France.
Chachaty, C. 1968. "Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements." France.
@misc{etde_20523321,
title = {Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements}
author = {Chachaty, C}
abstractNote = {The electron spin resonance (E.S.R.) spectra of gamma irradiated polar organic glasses, at 77 K, shows a single line centered at g {approx} 2, attributed to solvated electrons. The radicals produced on scavenging this species by electron acceptors, such as aromatic hydrocarbons, nitro-compounds and azines have been studied by E.S.R. In most cases, the radicals from these solutes, the spectra of which are observed after elimination by warming of the radicals from the matrices, are produced by protonation of the anions formed by scavenging of electrons at 77 K. Thus, in the case of glassy solutions of nitro-compounds, the radicals R NO{sub 2}H are formed. They are characterized by a{sub N} = 15 G (nitrobenzene) or a{sub N} = 28 G (nitro-alkane). These radicals are also generated by U.V, photolysis at room temperature of solutions of nitro-compounds in alcohols and are shown to be the precursors of nitroxide radicals R - N - R (with N - O) observed simultaneously. Gamma irradiation of solutions of pyridine and of the three diazines, in alcohol glasses at 77 K, produces the radical formed by hydrogen addition to these compounds. The value of the coupling constant of the additional proton (7-10 G) indicates that it is bound to a nitrogen in the sp{sup 2} hydridation state. One has shown, taking pyridine as an example, that the addition to a carbon gives a much greater value of the coupling constant, of the order of 50-60 G. (author) [French] Les spectres de resonance paramagnetique electronique (R.P.E.) obtenus apres irradiation gamma, a 77 K, de verres organiques polaires tels que les alcools, comportent une bande unique centree a g {approx} 2, attribuable aux electrons solvates. On etudie par R.P.E. les radicaux provenant de leur capture par des solutes ayant une affinite electronique, en particulier les hydrocarbures aromatiques, les composes nitres et les azines. En general, les radicaux provenant de ces solutes, dont on observe les spectres apres elimination specifique des radicaux de la matrice par rechauffement, resultent de la protonation des anions formes par capture des electrons a 77 K. Ainsi, dans le cas de solutions vitreuses de composes nitres, il se forme les radicaux R NO{sub 2}H caracterises par a{sub N} = 15 G (nitrobenzene) ou a{sub N} = 28 G (nitro-alcanes). On observe transitoirement ces memes radicaux par photolyse U.V. de solutions de composes nitres dans les alcools, a temperature ambiante, dans la cavite du spectrometre et l'on montre qu'ils sont les precurseurs de radicaux nitroxydes R - N - R (avec N - O) observes simultanement. Les solutions de pyridine et des trois diazines dans les alcools, irradiees a 77 K donnent les radicaux produits par addition d'hydrogene sur ces composes. Il semble que le proton supplementaire, dont la constante de couplage est de 7 a 10 G, soit lie a un azote dans l'etat d'hybridation sp{sup 2}. On montre que l'addition sur un carbone donnerait une constante de couplage beaucoup plus elevee, de l'ordre de 50 a 60 G, dans le cas de la pyridine. (auteur)}
place = {France}
year = {1968}
month = {Jun}
}