Coronene

Coronene

Names
Preferred IUPAC name Coronene
Other names [6]circulene X1001757-9, superbenzene
Identifiers
CAS Number	191-07-1 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:29863 Y
ChemSpider	8761 Y
ECHA InfoCard	100.005.348
KEGG	C19375 N
PubChem	9115
InChI InChI=1S/C24H12/c1-2-14-5-6-16-9-11-18-12-10-17-8-7-15-4-3-13(1)19-20(14)22(16)24(18)23(17)21(15)19/h1-12H Y Key: VPUGDVKSAQVFFS-UHFFFAOYSA-N Y InChI=1/C24H12/c1-2-14-5-6-16-9-11-18-12-10-17-8-7-15-4-3-13(1)19-20(14)22(16)24(18)23(17)21(15)19/h1-12H Key: VPUGDVKSAQVFFS-UHFFFAOYAQ
SMILES c1cc2ccc3ccc4ccc5ccc6ccc1c7c2c3c4c5c67
Properties
Chemical formula	C24H12
Molar mass	300.36 g·mol−1
Appearance	white or pale yellow powder
Melting point	438 °C (820 °F; 711 K)
Boiling point	525 °C (977 °F; 798 K)
Solubility in water	0.14 μg/L
Solubility	very soluble: benzene, toluene, hexane, and ethers, sparingly soluble in ethanol
Magnetic susceptibility (χ)	-243.3·10−6 cm3/mol
Hazards
Main hazards	flammable
EU classification (DSD)	F
R-phrases	R10 R20/21/22
S-phrases	S45
Structure
Point group	D6h
Dipole moment	0 D
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Coronene (also known as superbenzene) is a polycyclic aromatic hydrocarbon (PAH) comprising six peri-fused benzene rings. Its chemical formula is C
24H
12. It is a yellow material that dissolves in such solvents as benzene, toluene, and dichloromethane. Its solutions emit blue light fluorescence under UV light. Its emission spectrum is not symmetrical with its excitation spectrum and varies in the number of bands and their relative intensities depending on the solvent. It has been used as a solvent probe, similar to pyrene.

It occurs naturally as the very rare mineral carpathite, which is 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.

Coronene is produced in the petroleum-refining process of hydrocracking, where it can dimerize to a fifteen ring PAH, trivially named "dicoronylene" (formally named benzo[10,11]phenanthro[2',3',4',5',6':4,5,6,7]chryseno[1,2,3-bc]coronene or benzo[1,2,3-bc:4,5,6-b'c']dicoronene).

The compound is of theoretical interest to organic chemists because of its aromaticity. It can be described by 20 resonance structures or by a set of three mobile Clar sextets. In the Clar sextet case, the most stable structure for coronene has only the three isolated outer sextets as fully aromatic although superaromaticity would still be possible when these sextets are able to migrate into the next ring.