Hexaphenylbenzene

The compound is the parent member of a wider class of hexaarylbenzenes, which are mainly of theoretical interest.

[2] It is prepared by heating tetraphenylcyclopentadienone and diphenylacetylene in benzophenone or other high-temperature solvent.

[1] Together with 1,2,3,4-tetraphenylnaphthalene, hexaphenylbenzene forms by the chromium-catalyzed oligomerization of diphenylacetylene.

[3] It may also be prepared by the dicobalt octacarbonyl-catalyzed alkyne trimerisation of diphenylacetylene.

The molecule adopts a propeller-like conformation in which the phenyl rings are rotated about 65°,[4] while in the gas phase, they are perpendicular with some slight oscillations.

Perspective view of the crystal structure of hexaphenylbenzene, showing the rotation of the phenyl rings. Hydrogen atoms have been omitted for clarity. [ 4 ]