Coronene

Occurrence and synthesis

Coronene occurs naturally as the very rare mineral carpathite, characterized by flakes of pure coronene embedded in sedimentary rock. This mineral may be created from ancient hydrothermal vent activity. In earlier times this mineral was also called karpatite or pendletonite.

The presence of coronene putatively formed from contact of magma with fossil fuel deposits has been used to argue that Permian-Triassic "Great Dying" event was caused by a greenhouse gas warming episode triggered by large-scale Siberian vulcanism.

Coronene is produced in the petroleum-refining process of hydrocracking, where it can dimerize to a fifteen ring PAH, trivially named "dicoronylene". Centimeter-long crystals can be grown from a supersaturated solution of molecules in toluene (ca. 2.5 mg/ml), which is slowly cooled (ca. 0.04 K/min) from 328 K to 298 K over a period of 12 hours.

Structure

Coronene is a planar circulene. It forms needle-like crystals with a monoclinic, herringbone-like structure. The most common polymorph is γ, but β form can also be produced in an applied magnetic field (ca. 1 tesla) The structure containing two C-H groups on one benzene ring, so-called DUO, was analyzed by infrared spectroscopy.

Other uses

Coronene has been used in the synthesis of graphene. For example, coronene molecules evaporated onto a copper surface at 1000 degrees Celsius will form a graphene lattice which can then be transferred onto another substrate.

References

Cited sources

References

1. (2014). "Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book)". [[Royal Society of Chemistry.
2. Haynes, p. 3.128
3. Haynes, p. 5.145
4. Bertarelli, Chiara. [http://home.dei.polimi.it/sampietr/ESO/OK-03-Bertaelli-lezione2.pdf Molecules for organic electronics: intermolecular interactions vs properties]. Dipartimento di Chimica, Politecnico di Milano
5. (2017). "Donor–acceptor single cocrystal of coronene and perylene diimide: molecular self-assembly and charge-transfer photoluminescence". RSC Adv..
6. Haynes, p. 12.95
7. Chemspider, https://legacy.chemspider.com/Chemical-Structure.8761.html
8. Haynes, p. 6.156
9. Fetzer, J. C.. (2000). "The Chemistry and Analysis of the Large Polycyclic Aromatic Hydrocarbons". Wiley.
10. [https://web.archive.org/web/20060205175225/http://luminousminerals.com/karpatite.shtml Karpatite]. luminousminerals.com
11. [http://www.mindat.org/min-2162.html Carpathite]. mindat.org
12. (2020). "Pulsed volcanic combustion events coincident with the end-Permian terrestrial disturbance and the following global crisis". Geology.
13. (2016). "An unforeseen polymorph of coronene by the application of magnetic fields during crystal growth". Nature Communications.
14. (2018). "An Alternative Strategy to Polymorph Recognition at Work: The Emblematic Case of Coronene". Crystal Growth & Design.
15. (2018-09-18). "Quantitative Analysis of Zigzag and Armchair Edges on Carbon Materials with and without Pentagons Using Infrared Spectroscopy". Analytical Chemistry.