Investigation of pyridine extracts and residues of coals by solid-state 13C n.m.r. spectroscopy
β Scribed by Gaye Erbatur; Oktay Erbatur; Mark F. Davis; Gary E. Maciel
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 864 KB
- Volume
- 65
- Category
- Article
- ISSN
- 0016-2361
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π SIMILAR VOLUMES
13C solid-state n.m.r, spectra of samples of 14 coals and their pyridine residues representative of the three depositions in the Shanxi province of the People's Republic of China are described in detail. The results confirm those of previous infrared spectroscopy in showing these vitrinite-inertinit
Three Polish coal samples (flame coal, gas coal and orthocoking coal) and their macerals were studied in the solid state by means of 13C cross polarization/magic angle spinning n.m.r. and FT-i.r. spectroscopies. Several structural parameters derived from these analyses allow the characterization of
The quantitative aspects of cross-polarization (CP), which is used in conjunction with dipolar decoupling and magic-angle rotation to obtain high resolution 13C n.m.r. spectra of coals, have been studied using a bituminous coal (82 wt% C, dmmf basis) and asphaltenes from an extract of the same coal.
## Magic-angle 13C n.m.r. spectra have been obtained for a series of vitrinite concentrates. Proper modification of the cross-polarization pulse sequence allows separation of protonated and nonprotonated carbon resonances. This technique is used to determine the relative fraction of nonprotonated
## Abstract ^13^C chemical shifts for 23 __para__β and __meta__βsubstituted chalcones of the types **1** and **2** have been determined. The aromatic shieldings are compared with previous results for other aromatic derivatives. Correlations of the ^13^C chemical shifts of vinyl carbons and carbonyl