Variable temperature EPR studies of Illinois No. 6 coal treated with donor and acceptor molecules

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370422

Thompson, R L; Rothenberger, K S; Retcofsky, H L ^[1]

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1. Pittsburgh Energy Technology Center, Pittsburgh, PA (United States)

Variable, temperature EPR studies of Illinois No. 6 coal, its pyridine extract, and samples of each after treatment with known donor and acceptor molecules are reported. The purpose of the study was to explore the origin of the EPR signals near g = 2 and to assess the contribution of certain non-bonded interactions in coal. Curie Law behavior is exhibited for each sample indicating that the EPR signals are dominated by doublet state radicals. No evidence for thermally accessible, low-lying triplet states, such as those found in some charge-transfer complexes, was found. Infrared spectroscopy reveals, however, that some electron density is transferred from the coal after treatment with acceptors such as TCNQ and TCNE. EPR studies of chromat graphic fractions of the pyridine extract (approximately five percent of the whole coal), both untreated and treated with TTF and TCNE, indicated some minor contributions of low-lying triplet states.

• OSTI ID: 370422
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
66 PHYSICS
BITUMINOUS COAL
COAL EXTRACTS
ELECTRON DENSITY
ELECTRON SPIN RESONANCE
INFRARED SPECTRA
MOLECULES
PYRIDINE