Hexamethylbenzene

Hexamethylbenzene
Structural formula of hexamethylbenzene
Ball-and-stick model of the hexamethylbenzene molecule
Names
IUPAC name
1,2,3,4,5,6-Hexamethylbenzene
Other names
Mellitene
Identifiers
87-85-4 Yes
ChEBI CHEBI:39001 
ChemSpider 6642 
Jmol-3D images Image
PubChem 6908
Properties
Molecular formula
C12H18
Molar mass 162.27 g·mol−1
Appearance White crystalline powder
Melting point 165 °C (329 °F; 438 K)
Boiling point 265.2 °C (509.4 °F; 538.3 K)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Hexamethylbenzene is white crystalline solid with chemical formula C6(CH3)6. It is an aromatic hydrocarbon with six methyl groups stemming from the carbon centres of the ring. Hexamethylbenzene has historical significance in the field of X-ray crystallography. In 1929, Kathleen Lonsdale first proved the shape of hexamethylbenzene and thus showed that the benzene ring is hexagonal and flat.[1]

Uses

Hexamethylbenzene has no significant commercial uses. The six methyl groups enhance the proton affinity of the central ring.[2] Because it is electron-rich, hexamethylbenzene can be used as a ligand in organometallic chemistry. Two examples from organoruthenium chemistry are the sandwich complexes Ru(ɳ4-C6(CH3)6)(ɳ6-C6(CH3)6) and the dication [Ru(ɳ6-C6(CH3)6)2]2+.[3]

Hexamethylbenzene has been used as a solvent for 3He-NMR spectroscopy.[4]

Preparation

Hexamethylbenzene can be prepared by the reaction of phenol with methanol at 400 °C in the presence of an alumina catalyst.[5]

References

  1. Lonsdale, Kathleen (1929). "The Structure of the Benzene Ring in Hexamethylbenzene". Proceedings of the Royal Society A 123 (792): 494–515. doi:10.1098/rspa.1929.0081.
  2. Earhart., H. W.; Komin, Andrew P. (2000), "Polymethylbenzenes", Kirk-Othmer Encyclopedia of Chemical Technology, New York: John Wiley, doi:10.1002/0471238961.1615122505011808.a01, ISBN 9780471238966
  3. Bennett, M. A.; Huang, T. N.; Matheson, T. W.; Smith, A. K. (1982). "(η6-Hexamethylbenzene)Ruthenium Complexes". Inorganic Syntheses 21: 74–78. doi:10.1002/9780470132524.ch16. ISBN 9780470132524.
  4. Saunders, M.; Jimenez-Vazquez, H. A.; Khong, A. (1996). "NMR of 3He Dissolved in Organic Solids". J. Phys. Chem. 100 (39): 15968–15971. doi:10.1021/jp9617783.
  5. Landis, Phillip S.; Haag, Werner O. (1963). "Formation of Hexamethylbenzene from Phenol and Methanol". The Journal of Organic Chemistry 28 (2): 585. doi:10.1021/jo01037a517.