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Badania składu chemicznego żywicopodobnej materii znalezionej w postaci inkluzji w węglu kamiennym

Antkowiak W.Z.

Wiadomości Chemiczne

2008

[Z] 62, 1-2

115-133

An inhomogeneous resinous material of a yellow to tea-like colour and of an elastic to hard consistency was found as a thin layer inserted between coal seams. An explanation of its origin and chemical composition is now being of particular interest to geologists. The resin was found to be composed of carbon, hydrogen, nitrogen and, by assumption, oxygen. The radiocarbon dating measurement carried out on the raw resin gave a value of 8490 š 50 years BP and an explanation of this result is suggested. Only about one third of the raw resin was soluble in organic solvents at temperatures below 100°C. The etched insoluble amorphous residue that stays solid up to 260°C and reveals carbonyl absorption in IR, when subjected to transesterification in methanol at reflux in the presence of sodium methoxide yielded quantitatively a soluble in chloroform product, which shows an optical activity and proved to be a difficult to separate mixture of methyl esters and alcoholic moiety. The etching of the raw resin with hot water gave an optically inactive mixture of double homologues of poly(oxyethylene)-poly(oxypropylene) glycol structure, that differ one from the other in a number of methylene and oxyethylene groups. The product revealed a characteristic ESI-MS spectrum, the pattern of which could be seen in almost every fraction obtained by extraction of the raw resin with different organic solvents or its transesterification product mixture. The physical properties, other than ESI-MS, showed in the resinous material the presence of some additional components different from polyethylene-polypropylene glycol homologues. The polyurethane character of the resin was demonstrated by identification of bis(4-isocyanatophenyl)methane in the chloroform extract of the raw resin as a secondary product formed in the thermal conditions of GC-MS, and of bis[4-(methoxycarbonylamino)phenyl]methane which occurred in the transesterification product mixture. Additionally, the presence of methyl 9-octadecenoate, accompanied by methyl esters of other fatty acids, was also determined. Finally, after several repeated column and plate chromatographic separations, two "homogeneous" substances of [?]D = +25.7° and +20.2°, respectively, the main components responsible for the optical activity of most resinous fractions, were isolated from the transesterification product mixture. The principal products of these "chromatographically pure" substances turned out to have the adduct structure of methyl ricinoleate and bis(4-isocyanatophenyl)methane. It was proved that in the case of a compound revealing the higher specific rotation, two molecules of methyl ricinoleate were bound, using their OH functions, to one molecule of diisocyanate, giving bis[4-(1-methoxy-1-oxo-9-octadecen-12-yloxycarbonylamino)phenyl]methane. The molecular structure of a compound with lower specific rotation was composed of one molecule of methyl ricinoleate and one molecule of methanol, both bound to diisocyanate to give [4-(1-methoxycarbonylamino)phenyl][4-(1-methoxy-1-oxo-9-octadecen-12-yloxycarbonylamino)phenyl]methane. No components were found of a struc-ture which might indicate the ancient, natural origin of the resinous material. Keywords: resinous inclusions in coal, poly(oxyethylene)-poly(oxypropylene) glycol, double homologue mixture, methyl ricinoleate, urethanes derived from bis(4-isocyanatophenyl)methane, ESI mass spectra.