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Hexa-peri-benzocoronene (HBC), or, more commonly, hexabenzocoronene, is a planar polycyclic aromatic hydrocarbon (PAH). Structurally, it consists of a central benzene ring surrounded first by six more benzene rings to form聽coronene1, which in turn is surrounded by six additional benzenes for a total of 13 rings. HBC is in the聽D6h聽symmetry group.
Two HBC syntheses appeared in 1958. In one, A. Halleux, R. H. Martin, and G. S. D. King at European Research Associates (Brussels)聽聽to make the molecule: the cyclodehydrogenation of hexaphenylbenzene2聽and the reaction of dibenz-1,9;2,3-anthrone3聽with Zn/ZnCl2. They also isolated two new hydrocarbons from the Zn/ZnCl2聽reaction.
In the other synthesis, E. Clar and C. T. Ironside at the University of Glasgow first treated 2,3,7,8-dibenzoperinaphthene with bromine, then heated the brominated product to form tetrabenzoperopyrene4聽(TBP) Additional heating聽. The authors also reported that HBC emits orange-yellow phosphorescence in solid solution at low temperatures.
In 2014, Andreas Hirsch and collaborators at the University of Erlangen鈥揘uremberg (Germany) synthesized a compound in which聽5. The authors stated that this 鈥渄yad鈥� could serve as a versatile template for optoelectronic applications. X-ray crystallography showed that the bond distance between the two aromatic components is only 3.17 脜.
In another example of HBC and its derivatives combined with other chemical structures, Aleksey E. Kuznetsov at Federico Santa Mar铆a Technical University (Santiago, Chile)聽聽(isophlorins). In this theoretical study, the author found that isophlorins had profound effects on the structural and electronic properties of the dyads and therefore likely their reactivities.
Although PAHs similar to HBC are known carcinogens, there are no reports in the literature of its carcinogenicity.
1. CAS Reg. No. 191-07-1.
2. CAS Reg. No. 992-04-1.
3. CAS Reg. No. 86854-05-9.
4. CAS Reg. No. 190-22-7.
5. CAS Reg. No. 99685-96-8; MOTW for聽June 11, 2018.
Hexa-peri-benzocoronene hazard information
| Hazard class* | GHS code and hazard statement | |
|---|---|---|
| Acute toxicity, oral, category 4 | H302鈥擧armful if swallowed聽 |  |
| Acute toxicity, dermal, category 4 | H312鈥擧armful in contact with skin | |
| Acute toxicity, inhalation, category 4 | H332鈥擧armful if inhaled | |
*Globally Harmonized System (GHS) of Classification and Labeling of Chemicals.聽
MOTW updates
Uranium hexafluoride1 (UF6) was the Molecule of the Week for February 28, 2011. It is a covalent compound used primarily for separating uranium isotopes. In a recent article, Kirk Peterson, Puru Jena, Kit H. Bowen, and colleagues at Johns Hopkins University (Baltimore), Washington State University (Pullman), and Virginia Commonwealth University (Richmond) used photoelectron spectroscopy and quantum chemistry to demonstrate the degree to which gold can act as a surrogate to fluorine in UF6. They found that, unlike UF6, UAu6 shows that result in three low-lying isomers with 3-D or quasi-2-D structures.
Sulfuryl fluoride2 (SO2F2) was the Molecule of the Week for March 23, 2009. It is a relatively unreactive gas that is commonly used as a fumigant for controlling termites. It is also a greenhouse gas 4800 times more potent than CO2 with high atmospheric persistence. In October, two environmental organizations filed a legal petition with the California Air Resources Board to because of the chemical鈥檚 strong ability to trap heat in the atmosphere.
1. CAS Reg. No. 7783-81-5.
2. CAS Reg. No. 2699-79-8.
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Hexa-peri-产别苍锄辞肠辞谤辞苍别苍别听fast facts
| CAS Reg. No. | 190-24-9 |
| SciFinder nomenclature | Hexabenzo[bc,ef,hi, kl,no,qr] coronene |
| Empirical formula | C42H18 |
| Molar mass | 522.59 g/mol |
| Appearance | Yellow to orange-yellow crystals or powder |
| Melting point | >600 掳C |
| Water solubility | Insoluble |
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