Coal extracts, spectra

The spectrum of m/e 398 is identical for ALBl and POWl extracts. The compound is not adiantane since the intensity of the m/e 191 peak is greater than 177, not similar (13). C27 - C31 Triterpanes, especially adiantane, C29, have been found in bituminous coal extracts (14). 

Figures 5-7 are the spectra exhibiting the thermally extracted mobile phase components over different temperature intervals. All five coals mentioned in Figures 5-7 show distinct mass spectra in the mobile phase compared to the spectra of the macromolecular structure (25) and contain alkylsubstituted naphthalenes in the mobile phase although their relative amounts are dependent on coal characteristics. In general, (the temperature where the maximum rate occurs) in Py-FIMS was in the range of 430-470 C for bituminous rank coals. Around T, the macromolecular structure of bituminous rank coals is decomposed to yield FI spectrum showing the dominant peaks of alkylsubstituted phenols. Detailed FI spectra of the macromolecular structure for the ANL-PCS coals mentioned in Figures 5-7 are illustrated elsewhere (25).

CHARACTERIZATION of the PYRIDINE-EXTRACT. Pyridine is known to cling to coals. The extract was therefore stirred with a methanol/water/HCl mixture for two days as suggested by Buchanan.(lS) Elemental analysis of the extract revealed 1.85% N. The original coal contained 1.92% N (daf) so it is apparent that the methanol/water/HCl treatment followed by drying successfully removed pyridine from the extract. The FTIR spectrum of the extract did not reveal the presence of pyridine. 

The O-methylated extract was derivatized with 99 percent C-enriched methyl iodide. The NMR spectrum of the extract showed a strong absorption at 56 ppm (relative to TMS), which can be attributed to unhindered aryl methyl ethers (67%), a smaller absorption at 60 ppm, attributable to hindered aryl methyl ethers (23%), and a resonance at 51 ppm, assignable to methyl esters derived from carboxylic acids (10%).(16) TTiese results are consistant with those of Liotta l al, who studied the alkylation of whole Illinois No. 6 coal.(12)... 

The infrared spectra of the coal and the various extracts were recorded on a Baird, Model GY-1 (Ireland Mine vitrain concentrate) and on a Perkin Elmer Model 337 spectrophotometer (Bruceton coal). The samples were prepared by the potassium bromide pellet technique. The high resolution proton NMR spectrum of the benzene soluble extract from Ireland Mine vitrain concentrate was recorded on a Varian A-60 spectrometer in 10% deuterated chloroform (CDCh) solution, using tetrametnylsilane internal standard. 

C. T. Pillinger. It has been found in shungite a Precambrian coal from Karelia. I have a sample of shungite which we have tried to extract with toluene to see whether we could obtain a spectrum with peaks corresponding to C60. This is very recent data and our initial results are not promising. 

Other evidence from carbon-13 magnetic resonance studies of the carbon disulfide extract of coal also favors the occurrence of small-ring systems. The mean structural unit appears to consist of two-to-three ring condensed aromatic systems with 40% of the available aromatic carbons bearing alkyl, phenolic, and/or naphthenic groups. Indeed, the mass spectrum of the extract indicated the presence of alkyl aromatic compounds having from 1 to 10 or more alkyl carbons per molecule. 

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