Hexaphenylbenzene: Difference between revisions

|Watchedfields = changed

|verifiedrevid = 400368712

|ImageFile = Structural formula of hexaphenylbenzene.svg

|ImageFile2 =Hexaphenylbenzene_xtal.png

|PIN = 2³,2⁴,2⁵,2⁶-Tetraphenyl-1¹,2¹:2²,3¹-terphenyl

|OtherNames = Hexaphenylbenzene

|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

|InChIKey = QBHWPVJPWQGYDS-UHFFFAOYAG

|StdInChI_Ref = {{stdinchicite|correct|chemspider}}

|StdInChI = 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

|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

|StdInChIKey = QBHWPVJPWQGYDS-UHFFFAOYSA-N

|CASNo_Ref = {{cascite|correct|??}}

|CASNo =992-04-1

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 35L5JAJ94N

|PubChem =70432

|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

|ChemSpiderID = 63611

|SMILES = c1cc(ccc1)c3c(c(c(c(c3c2ccccc2)c4ccccc4)c5ccccc5)c6ccccc6)c7ccccc7

|C=42|H=30

|Appearance = white solid

|MeltingPtC = 454 to 456

|MeltingPt_ref = <ref name = fieser/>

}}

'''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.<ref name="hexaarylbenzene review">{{cite journal|title=Hexaarylbenzene: Evolution of Properties and Applications of Multitalented Scaffold|author=Varun Vij, Vandana Bhalla, and Manoj Kumar|journal=Chemical Reviews|year=2016|volume=116|issue=16|pages=9565–9627|doi=10.1021/acs.chemrev.6b00144|pmid=27498592}}</ref>

==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.<ref name = fieser>{{cite journal| title = Hexaphenylbenzene | journal = Organic Syntheses | author = Louis Fieser | volume= 46 | pages = 44| year = 1966|doi=10.15227/orgsyn.046.0044}}</ref>

Together with 1,2,3,4-tetraphenylnaphthalene, hexaphenylbenzene forms by the chromium-catalyzed oligomerization of [[diphenylacetylene]].<ref>{{cite journal|title=π-Complexes of the Transition Metals. X. Acetylenic π-Complexes of Chromium in Organic Synthesis|author=W. Herwig, W. Metlesics, H. Zeiss|journal=J. Am. Chem. Soc.|year=1959|volume=81|issue=23|pages=6203–6207|doi=10.1021/ja01532a024}}</ref> It may also be prepared by the [[dicobalt octacarbonyl]]-catalyzed [[alkyne trimerisation]] of diphenylacetylene.<ref name="hexaarylbenzene review"/>

:[[Image:Diphenylacetylene cyclotrimerization.png|500px|Diphenylacetylene cyclotrimerization using dicobalt octacarbonyl]]

==Structure==

[[File:Hexaphenylbenzene xtal perspective.png|thumb|left|Perspective view of the crystal structure of hexaphenylbenzene, showing the rotation of the phenyl rings. Hydrogen atoms have been omitted for clarity.<ref name = bart/>]]

The stable [[Conformational isomerism|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°,<ref name = bart>{{cite journal | doi = 10.1107/S0567740868004176 | title = The crystal structure of a modification of hexaphenylbenzene | year = 1968 | last1 = Bart | first1 = J. C. J. | journal = Acta Crystallographica Section B | volume = 24 | issue = 10 | pages = 1277–1287 | url = http://journals.iucr.org/b/issues/1968/10/00/a06258/a06258.pdf }}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> while in the gas phase, they are perpendicular with some slight oscillations.<ref>{{cite journal |title= Restricted Rotation in Hexaarylbenzenes |author= Gust, D. |journal= [[J. Am. Chem. Soc.]] |year= 1977 |volume= 99 |issue= 21 |pages= 6980–6982 |doi= 10.1021/ja00463a034}}</ref>

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[[Category:Benzene derivatives]]

[[Category:Phenyl compounds]]