Electron spin mapping of coal molecular structure by ENDOR. Quarterly technical progress report
We have shown how the use of ENDOR spectroscopy can accurately measure the proton coupling constants of the radical formed when a benzene or d/sub 6/-benzene solution of perylene is contacted with various activated aluminas, silica, and the silica-alumina catalyst M-46 (Houdry). The surface dynamics as a function of temperature of the radical can be followed by observing the growth and disappearance of the matrix ENDOR lines for protons and deuterons. At low temperatures, we have shown that on alumina there is a dipole-dipole interaction between the radical and the /sup 27/Al nuclei on the surface. A detailed study of this resonance lineshape should enable us to develop a clearer picture of the arrangement of aluminium atoms at the adsorption sites for perylene. The absence of this resonance in the ENDOR spectra of perylene on the aluminosilicate strongly suggests that a different adsorption site or surface chemistry exists in this system. In the ENDOR spectra of perylene on the aluminosilicate (and to a lesser extent on alumina) we see additional ENDOR resonances which we have assigned to the perylene cation dimer radical. The existence of such a species in solution has been reported by others, and the benzene dimer cation radical formed by the uv irradiation of benzene adsorbed on alumina has also been reported. We believe that the presence of the cation dimer radical is strong evidence suggesting that the monomer radical we observe by ENDOR spectroscopy is the perylene cation radical. 19 refs., 5 figs.
- Research Organization:
- Illinois Univ., Urbana (USA)
- DOE Contract Number:
- FG22-84PC70782
- OSTI ID:
- 6364123
- Report Number(s):
- DOE/PC/70782-5; ON: DE86002491
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ALUMINIUM SILICATES
AROMATICS
BENZENE
CARBONACEOUS MATERIALS
CATALYSTS
CHALCOGENIDES
COAL
CONDENSED AROMATICS
ENDOR
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
MAGNETIC RESONANCE
MATERIALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PERYLENE
RADICALS
RESONANCE
SILICATES
SILICON COMPOUNDS
STRUCTURAL MODELS