Spin-mapping of coal structures with ESE and ENDOR

Technical Report · Sat Dec 01 00:00:00 EST 1990

DOI:https://doi.org/10.2172/5249824· OSTI ID:5249824

Belford, R L; Clarkson, R B

To ENDOR and ESE we have added another advanced EPR technique. VHF-EPR, as a tool with which to observe coal molecular structure, especially organic sulfur. We have constructed a unique VHF EPR instrument operating at the W-band (96 Ghz), one of only two such instruments in the world, and the only one studying coal. We are employing this instrument, as well as collaborating with scientists at Cornell University, who have a 250 GHz spectrometer, to develop a clearer understanding of the relationships between the VHF EPR spectra we observe from Illinois coal and the organic sulfur species present in it. Efforts in this quarter focussed on three area: recruitment of personnel (especially a new postdoctoral fellow) to join the coal research team work on improving the W-band spectrometer, and studies of vitrinite, sporinite, and fusinite macerals at G-band (250 GHz). All three areas have shown good progress. This report will discuss in detail the main features of the W-band instrument, stressing its unique engineering features as well as comparing it to the few other instruments in the world operating in the VHF frequency range (90--250 GHz). Preliminary analysis of the 250 GHz data on macerals obtained by density gradient centrifugation from an Illinois {number sign}6 coal gives the first indication that at the very highest frequencies, there may be a separation of the heteroatom VHF EPR signals into a sulfur and on oxygen-containing component. 15 refs., 9 figs., 1 tab.

• Research Organization: Univ. of Illinois at Urbana-Champaign, IL (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-88PC88921
• OSTI ID: 5249824
• Report Number(s): DOE/PC/88921-9; ON: DE92000301
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COAL
MOLECULAR STRUCTURE
SPECTROMETERS
DESIGN
PROGRESS REPORT
RESOLUTION
SPECTRA
CARBONACEOUS MATERIALS
DOCUMENT TYPES
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
MEASURING INSTRUMENTS
010600* - Coal
Lignite
& Peat- Properties & Composition
400102 - Chemical & Spectral Procedures