Cuneane

{{Short description|Saturated hydrocarbon compound (C8H8)}} {{Chembox | ImageFile = Cuneane-HF-Mercury-3D-balls.png | ImageFile_Ref = {{chemboximage|correct|??}} | ImageSize = 160 | ImageName = Ball and stick model of cuneane (1R,2R,3S,4S,5S,6R,7R,8S) | PIN = Pentacyclo[3.3.0.02,4.03,7.06,8]octane |Section1={{Chembox Identifiers | CASNo = 20656-23-9 | CASNo_Ref = {{cascite|correct|??}} | PubChem = 140734 | ChemSpiderID = 124127 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | SMILES = C12C3C4C3C5C1C2C45 | StdInChI = 1S/C8H8/c1-2-5(1)6-3-4(6)8(2)7(1)3/h1-8H | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = YIJMEXRVJPVGIY-UHFFFAOYSA-N | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} }} |Section2={{Chembox Properties | C=8 | H=8 | Density = 1.578 g/ml }} }}

'''Cuneane''' ({{ety|la|cuneus|wedge}}<ref>{{cite journal |author1=R. Criegee |author2=R. Askani | title = Octamethylsemibullvalene | journal = Angewandte Chemie International Edition in English | volume = 7 | issue = 7 | year = 1968 | pages = 537 | doi = 10.1002/anie.196805371}}</ref>) is a saturated hydrocarbon with the formula {{chem2|C8H8}} and a 3D structure resembling a wedge, hence the name. Cuneane may be produced from cubane by metal-ion-catalyzed σ-bond rearrangement.<ref>{{cite book |author1=Michael B. Smith |author2=Jerry March | title =March's Advanced Organic Chemistry | edition = 5th | publisher = John Wiley & Sons, Inc. | year = 2001 | pages = 1459 | isbn = 0-471-58589-0}}</ref><ref>{{cite journal |author1=Philip E. Eaton |author2=Luigi Cassar |author3=Jack Halpern | title = Silver(I)- and palladium(II)-catalyzed isomerizations of cubane. Synthesis and characterization of cuneane | journal = Journal of the American Chemical Society | volume = 92 | issue = 21 | year = 1970 | pages = 6366–6368 | doi = 10.1021/ja00724a061 |bibcode=1970JAChS..92.6366E }}</ref> Similar reactions are known for {{chem name|homocubane}} ({{chem2|C9H10}}) and bishomocubane ({{chem2|C10H12}}).<ref>{{cite journal |author1=Leo A. Paquette |author2=John C. Stowell | title = Silver ion catalyzed rearrangements of strained sigma. bonds. Application to the homocubyl and 1,1'-bishomocubyl systems | journal = Journal of the American Chemical Society | volume = 92 | issue = 8 | year = 1970 | pages = 2584–2586 | doi = 10.1021/ja00711a082 |bibcode=1970JAChS..92.2584P }}</ref><ref>{{cite journal |author1=W. G. Dauben |author2=M. G. Buzzolini |author3=C. H. Schallhorn |author4=D. L. Whalen |author5=K. J. Palmer | title = Thermal and silver ion catalyzed isomerization of the 1,1′-bishomocubane system: preparation of a new C10H10 isomer | journal = Tetrahedron Letters | volume = 11 | issue = 10 | year = 1970 | pages = 787–790 | doi = 10.1016/S0040-4039(01)97830-X }}</ref>

:thumb|left|300px|Synthesis of cuneane from cubane{{clear-left}}

== Molecular geometry == The carbon atoms in the cuneane molecule form a hexahedron with point group C2v. The cuneane molecule has three kinds of equivalent carbon atoms (A, B, C), which have also been confirmed by NMR.<ref>{{cite journal|author1=H. Guenther|author2=W. Herrig|doi=10.1002/cber.19731061217|issue=12|journal=Chemische Berichte|pages=3938–3950|title=Anwendungen der 13C-Resonanz-Spektroskopie, X. 13C,13C-Kopplungskonstanten in Methylencycloalkanen|volume=106|year=1973}}</ref> The molecular graph of the carbon skeleton of cuneane is a regular graph with non-equivalent groups of vertices, and so it is a very important test object for different algorithms of mathematical chemistry.<ref>{{cite journal |author1=M.I. Trofimov |author2=E.A. Smolenskii | title = Electronegativity of atoms of ring-containing molecules—NMR spectroscopy data correlations: a description within the framework of the topological index approach | journal = Russian Chemical Bulletin | year = 2000 | volume = 49 | issue = 3 | pages = 402 | doi = 10.1007/BF02494766|s2cid=95809728 }}</ref><ref>{{cite journal |author1=M.I. Trofimov |author2=E.A. Smolenskii | title = Application of the electronegativity indices of organic molecules to tasks of chemical informatics | journal = Russian Chemical Bulletin | year = 2005 | volume = 54 | issue = 9 | pages = 2235 | doi = 10.1007/s11172-006-0105-6|s2cid=98716956 }}</ref> :thumb|left|120px|Equivalent carbon atoms in cuneane{{clear-left}}

== Derivatives == Some cuneane derivatives have liquid crystal properties.<ref>{{cite journal |author1=Bényei, Gyula |author2=Jalsovszky, István |author3=Demus, Dietrich |author4=Prasad, Krishna |author5=Rao, Shankar |author6=Vajda, Anikó |author7=Jákli, Antal |author8=Fodor-Csorba, Katalin | title = First liquid crystalline cuneane-caged derivatives: a structure-property relationship study | journal = Liquid Crystals | year = 2006 | volume = 33 | issue = 6 | pages = 689–696 | doi = 10.1080/02678290600722940|bibcode=2006LoCr...33..689B |s2cid=97269476 }}</ref>

==References== {{Reflist}}

Category:Polycyclic nonaromatic hydrocarbons Category:Cyclopropanes Category:Cyclobutanes