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Hexamethylbenzene.svg Hexamethylbenzene-3D-balls.png
CAS number 87-85-4 YesY
PubChem 6908
ChemSpider 6642 N
Jmol-3D images Image 1
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 are 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 a synthetic 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]


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]


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


  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.