Abstract

Electron spin echo (e.s.e.) spectroscopy has been used in these laboratories to investigate proton hyperfine interactions in whole coal, separated coal macerals, synthetic lignites and model materials comprising perylene radical ions adsorbed on alumina and silica-alumina catalysts. The e.s.e. technique provides information that is complementary to electron nuclear double resonance in studying such interactions in coal. Coupling constants measured so far in evacuated samples of Illinois No. 6 agree well with models for condensed ring aromatic structures. Analysis of the proton matrix interactions are best fitted by r = 0.75 ± 0.05 nm, A iso = 0 and n = 40 protons. Matrix interactions from 13C nuclei also are seen. Coupling constants observed in a vitrain component separated from Illinois No. 6 coal are similar to those seen in the whole coal; the fact that the maceral does not exhibit all of the interactions found in whole coal suggests molecular structures to be specific to individual maceral types. Differences in the g-values of macerals may provide a direct, non-destructive route to the analysis of maceral-specific structure.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.