Hexaphenylbenzene

Hexaphenylbenzene is an aromatic compound composed of a benzene 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.^[2]

Hexaphenylbenzene

Names
Preferred IUPAC name 23,24,25,26-Tetraphenyl-11,21:22,31-terphenyl
Other names Hexaphenylbenzene
Identifiers
CAS Number	992-04-1 Y
3D model (JSmol)	Interactive image
ChemSpider	63611 Y
ECHA InfoCard	100.012.356
PubChem CID	70432
UNII	35L5JAJ94N Y
CompTox Dashboard (EPA)	DTXSID30243983
InChI InChI=1S/C42H30/c1-7-19-31(20-8-1)37-38(32-21-9-2-10-22-32)40(34-25-13-4-14-26-34)42(36-29-17-6-18-30-36)41(35-27-15-5-16-28-35)39(37)33-23-11-3-12-24-33/h1-30H Y Key: QBHWPVJPWQGYDS-UHFFFAOYSA-N Y InChI=1/C42H30/c1-7-19-31(20-8-1)37-38(32-21-9-2-10-22-32)40(34-25-13-4-14-26-34)42(36-29-17-6-18-30-36)41(35-27-15-5-16-28-35)39(37)33-23-11-3-12-24-33/h1-30H Key: QBHWPVJPWQGYDS-UHFFFAOYAG
SMILES c1cc(ccc1)c3c(c(c(c(c3c2ccccc2)c4ccccc4)c5ccccc5)c6ccccc6)c7ccccc7
Properties
Chemical formula	C42H30
Molar mass	534.702 g·mol−1
Appearance	white solid
Melting point	454 to 456 °C (849 to 853 °F; 727 to 729 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation

It is prepared by heating tetraphenylcyclopentadienone 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.^[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.^[2]

Structure

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

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°,^[4] while in the gas phase, they are perpendicular with some slight oscillations.^[5]