Hexaphenylbenzene

Hexaphenylbenzene
IUPAC name

1,2,3,4,5,6-hexa(phenyl)benzene
Identifiers
CAS number 992-04-1
PubChem 70432
ChemSpider 63611 Y
Jmol-3D images Image 1
Properties
Molecular formula C42H30
Molar mass 534.6876
Melting point

454-456 °C[1]
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Hexaphenylbenzene is an aromatic compound composed of a benzene ring substituted with six phenyl rings.

It may be prepared through a Diels-Alder reaction by refluxing tetraphenylcyclopentadienone and diphenylacetylene in benzophenone or other high-temperature solvent.[1]

Structure

Due to steric congestion among the phenyl rings, the stable conformation of this molecule has the phenyl rings rotated out of the plane of the central benzene ring. In the crystalline form shown on the left, the molecule forms a propeller-like conformation in which the phenyl rings are rotated about 65°,[2] while in the gas phase, they are perpendicular with some slight oscillations.[3]


References

  1. ^ a b Louis Fieser (1973), "Hexaphenylbenzene", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv5p0604 ; Coll. Vol. 5: 604 
  2. ^ a b Bart, J. C. J. (1968). "The crystal structure of a modification of hexaphenylbenzene". Acta Crystallographica, Section B: Structural Crystallography and Crystal Chemistry 24 (10): 1277. doi:10.1107/S0567740868004176. 
  3. ^ Gust, D. (1977). "Restricted Rotation in Hexaarylbenzenes". J. Am. Chem. Soc. 99 (21): 6980–6982. doi:10.1021/ja00463a034.