Hexaphenylbenzene is an

aromatic compound Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past grouping ...

composed of a

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

ring substituted with six phenyl rings. It is a colorless solid. The compound is the parent member of a wider class of hexaarylbenzenes, which are mainly of theoretical interest.

Preparation

It is prepared by heating

tetraphenylcyclopentadienone Tetraphenylcyclopentadienone is an organic compound with the formula (C6H5)4C4CO. It is a dark purple to black crystalline solid that is soluble in organic solvents. It is an easily made building block for many organic and organometallic compounds ...

and diphenylacetylene in benzophenone or other high-temperature solvent. The reaction proceeds via a Diels-Alder reaction to give the hexaphenyldienone, which then eliminates carbon monoxide. : Together with 1,2,3,4-tetraphenylnaphthalene, hexaphenylbenzene forms by the chromium-catalyzed oligomerization of diphenylacetylene.

Structure

The stable conformation of this molecule has the phenyl rings rotated out of the plane of the central benzene ring. The molecule adopts a propeller-like conformation in which the phenyl rings are rotated about 65°, while in the gas phase, they are perpendicular with some slight oscillations. {{clear, left

References

Benzene derivatives Hydrocarbons Phenyl compounds