Identification of a Novel Series of Benzohopanes and Their Geochemical Significance
Samo za registrovane korisnike
2016
Autori
Nytoft, Hans PeterVuković, Nikola S.
Kildahl-Andersen, Geir
Rise, Frode
Životić, Dragana R.
Stojanović, Ksenija A.
Članak u časopisu (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt
series of novel C-33-C-35 hexacyclic benzohopanes (C(33)b-C(35)b) were identified in 39 samples of coal extracts and 39 crude oils of different ages from all over the world. C(33)b and C(34)b homologues were isolated, and their structures were determined by nuclear magnetic resonance. The structure of C(35)b benzohopane was proposed based on the mass spectrum and its similarity with the mass spectra of structurally defined C(33)b and C(34)b homologues. The structures of the C(33)b-C(35)b hexacyclic benzohopanes are closely related to isohopanes; both groups are typical for terrestrial organic matter and can be useful in the correlation analysis. A possible pathway of formation of these novel benzohopanes and their hopanoid precursors with an additional branch in the aliphatic side chain is proposed. C(33)b-C(35)b hexacyclic benzohopanes are stable up to the maturity level corresponding to random vitrinite reflectance (Rr) of similar to 0.80%, which was demonstrated by analyzing the sam...ples of different maturity and by the maturation simulation experiments: hydrous pyrolysis of two bituminous coals (Rr = 0.55 and 0.59%) and pyrolysis of an extracted bituminous coal (Rr = 0.56%) and its asphaltenes. This represents a confirmation that the formation of these novel benzohopanes is related to specific depositional conditions and microbial activity during diagenesis. Mature samples (Rr = 0.8%) and hydrous pyrolysate of the bituminous coals (Rr lt 0.60%) obtained at 330 degrees C show a distinct distribution of benzohopanes in comparison to immature and moderately mature samples, which is characterized by a low abundance of the b series benzohopanes and the presence of regular and numerous other benzohopane isomers. The latter most likely represent isomers of regular and novel benzohopanes with different substitution patterns on the aromatic ring. This isomerization of alkyl groups attached to the aromatic ring, leading to the formation of thermodynamically more stable isomers, is a well-known maturation scenario so far reported in the series of alkylated naphthalenes, phenanthrenes, and dibenzothiophenes. Therefore, in the same way, a distribution of benzohopanes can indicate thermal maturity. In addition to the novel benzohopanes, three series (2 alpha, 2 beta, and 3 beta) of their methylated derivatives were identified in numerous samples. Finally, a novel C-35 heptacyclic benzohopane with an additional cyclopentane ring was also observed in the studied samples, and its structure was tentatively identified based on the mass spectrum. Opposite to the hexacyclic C(33)b-C(35)b benzohopanes, the formation of the C-35 heptacyclic benzohopane does not require a specific hopanoid precursor with two branches in the side chain. Therefore, this compound seems to have less geochemical significance than the new hexacyclic benzohopanes.
Izvor:
Energy and Fuels, 2016, 30, 7, 5563-5575Izdavač:
- Amer Chemical Soc, Washington
Finansiranje / projekti:
- Geohemijska ispitivanja sedimentnih stena - fosilna goriva i zagađivači životne sredine (RS-MESTD-Basic Research (BR or ON)-176006)
- Danish Research Council for Nature and Universe (FNU) [21-04-0605]
DOI: 10.1021/acs.energyfuels.6b00799
ISSN: 0887-0624
WoS: 000380523200040
Scopus: 2-s2.0-84979529780
Kolekcije
Institucija/grupa
Hemijski fakultet / Faculty of ChemistryTY - JOUR AU - Nytoft, Hans Peter AU - Vuković, Nikola S. AU - Kildahl-Andersen, Geir AU - Rise, Frode AU - Životić, Dragana R. AU - Stojanović, Ksenija A. PY - 2016 UR - https://cherry.chem.bg.ac.rs/handle/123456789/2283 AB - series of novel C-33-C-35 hexacyclic benzohopanes (C(33)b-C(35)b) were identified in 39 samples of coal extracts and 39 crude oils of different ages from all over the world. C(33)b and C(34)b homologues were isolated, and their structures were determined by nuclear magnetic resonance. The structure of C(35)b benzohopane was proposed based on the mass spectrum and its similarity with the mass spectra of structurally defined C(33)b and C(34)b homologues. The structures of the C(33)b-C(35)b hexacyclic benzohopanes are closely related to isohopanes; both groups are typical for terrestrial organic matter and can be useful in the correlation analysis. A possible pathway of formation of these novel benzohopanes and their hopanoid precursors with an additional branch in the aliphatic side chain is proposed. C(33)b-C(35)b hexacyclic benzohopanes are stable up to the maturity level corresponding to random vitrinite reflectance (Rr) of similar to 0.80%, which was demonstrated by analyzing the samples of different maturity and by the maturation simulation experiments: hydrous pyrolysis of two bituminous coals (Rr = 0.55 and 0.59%) and pyrolysis of an extracted bituminous coal (Rr = 0.56%) and its asphaltenes. This represents a confirmation that the formation of these novel benzohopanes is related to specific depositional conditions and microbial activity during diagenesis. Mature samples (Rr = 0.8%) and hydrous pyrolysate of the bituminous coals (Rr lt 0.60%) obtained at 330 degrees C show a distinct distribution of benzohopanes in comparison to immature and moderately mature samples, which is characterized by a low abundance of the b series benzohopanes and the presence of regular and numerous other benzohopane isomers. The latter most likely represent isomers of regular and novel benzohopanes with different substitution patterns on the aromatic ring. This isomerization of alkyl groups attached to the aromatic ring, leading to the formation of thermodynamically more stable isomers, is a well-known maturation scenario so far reported in the series of alkylated naphthalenes, phenanthrenes, and dibenzothiophenes. Therefore, in the same way, a distribution of benzohopanes can indicate thermal maturity. In addition to the novel benzohopanes, three series (2 alpha, 2 beta, and 3 beta) of their methylated derivatives were identified in numerous samples. Finally, a novel C-35 heptacyclic benzohopane with an additional cyclopentane ring was also observed in the studied samples, and its structure was tentatively identified based on the mass spectrum. Opposite to the hexacyclic C(33)b-C(35)b benzohopanes, the formation of the C-35 heptacyclic benzohopane does not require a specific hopanoid precursor with two branches in the side chain. Therefore, this compound seems to have less geochemical significance than the new hexacyclic benzohopanes. PB - Amer Chemical Soc, Washington T2 - Energy and Fuels T1 - Identification of a Novel Series of Benzohopanes and Their Geochemical Significance VL - 30 IS - 7 SP - 5563 EP - 5575 DO - 10.1021/acs.energyfuels.6b00799 ER -
@article{ author = "Nytoft, Hans Peter and Vuković, Nikola S. and Kildahl-Andersen, Geir and Rise, Frode and Životić, Dragana R. and Stojanović, Ksenija A.", year = "2016", abstract = "series of novel C-33-C-35 hexacyclic benzohopanes (C(33)b-C(35)b) were identified in 39 samples of coal extracts and 39 crude oils of different ages from all over the world. C(33)b and C(34)b homologues were isolated, and their structures were determined by nuclear magnetic resonance. The structure of C(35)b benzohopane was proposed based on the mass spectrum and its similarity with the mass spectra of structurally defined C(33)b and C(34)b homologues. The structures of the C(33)b-C(35)b hexacyclic benzohopanes are closely related to isohopanes; both groups are typical for terrestrial organic matter and can be useful in the correlation analysis. A possible pathway of formation of these novel benzohopanes and their hopanoid precursors with an additional branch in the aliphatic side chain is proposed. C(33)b-C(35)b hexacyclic benzohopanes are stable up to the maturity level corresponding to random vitrinite reflectance (Rr) of similar to 0.80%, which was demonstrated by analyzing the samples of different maturity and by the maturation simulation experiments: hydrous pyrolysis of two bituminous coals (Rr = 0.55 and 0.59%) and pyrolysis of an extracted bituminous coal (Rr = 0.56%) and its asphaltenes. This represents a confirmation that the formation of these novel benzohopanes is related to specific depositional conditions and microbial activity during diagenesis. Mature samples (Rr = 0.8%) and hydrous pyrolysate of the bituminous coals (Rr lt 0.60%) obtained at 330 degrees C show a distinct distribution of benzohopanes in comparison to immature and moderately mature samples, which is characterized by a low abundance of the b series benzohopanes and the presence of regular and numerous other benzohopane isomers. The latter most likely represent isomers of regular and novel benzohopanes with different substitution patterns on the aromatic ring. This isomerization of alkyl groups attached to the aromatic ring, leading to the formation of thermodynamically more stable isomers, is a well-known maturation scenario so far reported in the series of alkylated naphthalenes, phenanthrenes, and dibenzothiophenes. Therefore, in the same way, a distribution of benzohopanes can indicate thermal maturity. In addition to the novel benzohopanes, three series (2 alpha, 2 beta, and 3 beta) of their methylated derivatives were identified in numerous samples. Finally, a novel C-35 heptacyclic benzohopane with an additional cyclopentane ring was also observed in the studied samples, and its structure was tentatively identified based on the mass spectrum. Opposite to the hexacyclic C(33)b-C(35)b benzohopanes, the formation of the C-35 heptacyclic benzohopane does not require a specific hopanoid precursor with two branches in the side chain. Therefore, this compound seems to have less geochemical significance than the new hexacyclic benzohopanes.", publisher = "Amer Chemical Soc, Washington", journal = "Energy and Fuels", title = "Identification of a Novel Series of Benzohopanes and Their Geochemical Significance", volume = "30", number = "7", pages = "5563-5575", doi = "10.1021/acs.energyfuels.6b00799" }
Nytoft, H. P., Vuković, N. S., Kildahl-Andersen, G., Rise, F., Životić, D. R.,& Stojanović, K. A.. (2016). Identification of a Novel Series of Benzohopanes and Their Geochemical Significance. in Energy and Fuels Amer Chemical Soc, Washington., 30(7), 5563-5575. https://doi.org/10.1021/acs.energyfuels.6b00799
Nytoft HP, Vuković NS, Kildahl-Andersen G, Rise F, Životić DR, Stojanović KA. Identification of a Novel Series of Benzohopanes and Their Geochemical Significance. in Energy and Fuels. 2016;30(7):5563-5575. doi:10.1021/acs.energyfuels.6b00799 .
Nytoft, Hans Peter, Vuković, Nikola S., Kildahl-Andersen, Geir, Rise, Frode, Životić, Dragana R., Stojanović, Ksenija A., "Identification of a Novel Series of Benzohopanes and Their Geochemical Significance" in Energy and Fuels, 30, no. 7 (2016):5563-5575, https://doi.org/10.1021/acs.energyfuels.6b00799 . .