Accession Number : AD0849535

Title :   Structure and Reactivity of Energetic Chemical Species.

Descriptive Note : Annual summary rept. 1 Nov 67-31 Oct 68,

Corporate Author : KANSAS UNIV LAWRENCE DEPT OF CHEMISTRY

Personal Author(s) : Kevan, Larry ; Harmony, Marlin ; Christoffersen, Ralph

Report Date : DEC 1968

Pagination or Media Count : 157

Abstract : Energetic chemical species were investigated by both theoretical and experimental methods. The spatial distribution of trapped radicals in gamma-irradiated ethyleneglycol dimethacrylate polymers and of trapped electrons in gamma-irradiated methanol, ethanol and 2-methyltetrahydrofuran has been studied by paramagnetic relaxation methods. The radius within which electrons are trapped increases with decreasing polarity of the matrix. Charge storage in gamma-irradiated polymethylmethacrylate (PMMA) and other organic polymers doped with electron traps has been studied by measuring thermally-induced thermoelectric and ohmic currents. The conduction mechanism for the thermoelectric current in PMMA appears to be hole hopping between rotating carbomethoxy side groups. The origin of the ohmic currents is not yet clear. The theoretical technique for obtaining lower energy bounds has been extended to multi-electron, polyatomic molecules by using Gaussian basis orbitals. The use of Gaussians allows all integrals to be evaluated in closed form or by a single numerical integration. In the geminal theory of chemical bonding a new method for the determination of the best separated pair geminals of a closed shell molecule has been developed. The efficiency of triplet-triplet energy transfer in naphthalene-biacetyl mixtures has been studied. (Author)

Descriptors :   *ACRYLIC RESINS), *POLYMERS), *PHOSPHORESCENCE), (*FREE RADICALS, (*PARAMAGNETIC RESONANCE, (*NAPHTHALENES, RADIATION CHEMISTRY, GAMMA RAYS, SEEBECK EFFECT, RELAXATION TIME, ELECTRONS, MOLECULAR ORBITALS, MOLECULAR ENERGY LEVELS, WAVE FUNCTIONS.

Subject Categories : Radiation and Nuclear Chemistry
      Plastics
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE