:Cuneane

{{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[3.3.0.0^2,4.0^3,7.0^6,8]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}}{{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}}) 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.{{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}}{{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

}} Similar reactions are known for {{chem name|homocubane}} ({{chem2|C9H10}}) and bishomocubane ({{chem2|C10H12}}).{{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

}}{{cite journal

| journal = Tetrahedron Letters

| volume = 11

| issue = 10

| year = 1970

| pages = 787–790

| doi = 10.1016/S0040-4039(01)97830-X

}}

:File:CubaneToCun.png{{clear-left}}

Molecular geometry

The carbon atoms in the cuneane molecule form a hexahedron with point group C_2v.

The cuneane molecule has three kinds of equivalent carbon atoms (A, B, C), which have also been confirmed by NMR.{{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}} 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.{{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 }}{{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 }}

:File:Cuneane 2D.svg{{clear-left}}