Eldor investigations of radiation processes. Annual progress report, 1977--1978

Technical Report · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6666156

Kispert, L D

Research is reported devoted to examining the role of the host matrix as a function of temperature in determining the type and yield of radicals produced by X-irradiation of a crystalline or glass material using electron-electron double resonance (ELDOR), electron-nuclear double resonance (ENDOR), electron spin resonance (ESR), and heavy atom substitution techniques. After many years of research on the effects of radiation on crystalline materials, it is still difficult to predict from the thermal history, nature of radiation, crystal structure or form of the parent molecule what radical species will be stable at any given temperature. However, an examination of the ELDOR spectra of an irradiated substance results in a partial or complete measure of the relaxation mechanisms which, in turn, are related to the host matrix itself. The host matrix can be charged slightly by using the heavy atom substitution technique, by using different methods of crystallization, and by including radical precursors in clathrates, permitting a study of the relation among host matrix variation, radical yield, and relaxation parameters. ESR investigations carried out on single crystals of irradiated fluoro, chloro, and bromo derivatives of acetamide and acetic acid have shown that a large matrix effect is present which is dependent upon the leaving group size, crystal structure and degree of crystallization. ELDOR measurements between 5/sup 0/K and 370/sup 0/K have shown a large variation in ELDOR intensity dependent on intramolecular motion, quadrupole coupling, p-orbital anisotropy, spin diffusion and tunnelling rotation. Forbidden esr lines overlapped by intense esr lines, esr lines too broad to detect, ENDOR transitions and radical cluster have been studied by ELDOR.

• Research Organization: Alabama Univ., University (USA). Dept. of Chemistry
• OSTI ID: 6666156
• Report Number(s): ORO-4062-50
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ACETAMIDE
ACETIC ACID
AMIDES
BROMINE COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMISTRY
CHLORINE COMPOUNDS
ELDOR
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
ENDOR
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
IONIZING RADIATIONS
MAGNETIC RESONANCE
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RESEARCH PROGRAMS
RESONANCE
USES
X RADIATION