Raman spectroscopy as tool for the characterization of thio-polyaromatic hydrocarbons in organic minerals.
Benzothiophene and dibenzothiophene have been studied by Raman microspectroscopy using a 785 nm excitation wavelength. The spectra obtained have been compared with the previously measured spectra of idrialite, a complex natural mineral composed entirely of cata-condensed polyaromatic hydrocarbons (PAHs), usually containing a thiophenic or aliphatic five-membered ring. For comparison, the Raman spectra of 2,3-benzofluorene crystals have been obtained for the first time. Some of the bands in the idrialite spectra are attributed to specific vibrational modes of thiophene or fluorene-type PAHs, especially in the region below 1000 cm(-1). These modes at 495, 705 and 750 cm(-1) along with C-H or C-H(2) stretching modes around 3000 cm(-1) can be then used to distinguish such groups of PAHs in complicated organic mineral mixtures like idrialite.
Frank
Otakar
O
Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Prague 2, Czech Republic. frankota@natur.cuni.cz
Jehlicka
Jan
J
Edwards
Howell G M
HG
D037741:Fullerenes / Q000737:chemistry; D008903:Minerals / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods; D013457:Sulfur Compounds / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry
D037741:Fullerenes; D008903:Minerals; D011084:Polycyclic Aromatic Hydrocarbons; D013457:Sulfur Compounds; D013876:Thiophenes