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Title: Spin-mapping of coal structures with ESE (Electron Spin Echo) and ENDOR (Electron-Nuclear Double Resonance)

Technical Report ·
DOI:https://doi.org/10.2172/6409289· OSTI ID:6409289

Nondestructive chemical and physical characterization of whole Illinois coal and separated macerals, both before and after treatment by various desulfurization techniques is being performed using new electron magnetic resonance methods. The chemical structures of sulfur and non-sulfur containing organic species are being measured by the technique of Hyperfine Fingerprint Spectroscopy. Data on hyperfine couplings in a separated vitrinite maceral suggest the presence of small, condensed ring aromatic species, which may be linked by aliphatic bridging groups. Results from multi-frequency EPR experiments performed at X-, Q- and W-bands show slightly anisotropic spectra which have been analyzed by theoretical techniques developed in this laboratory. Analysis of the spectra reveals a nearly axial g-matrix, which agrees well with a model of planar conjugated aromatic species. The W-band data represents the first such experiments performed on coal and separated macerals. 4 refs., 3 figs., 1 tab.

Research Organization:
Illinois Univ., Urbana, IL (USA)
Sponsoring Organization:
DOE/FE
DOE Contract Number:
FG22-88PC88921
OSTI ID:
6409289
Report Number(s):
DOE/PC/88921-1; ON: DE91004333
Country of Publication:
United States
Language:
English