Cuneane

Cuneane (from Latin cuneus 'wedge'^[1]) is a saturated hydrocarbon with the formula C₈H₈ and a 3D structure resembling a wedge, hence the name. Cuneane may be produced from cubane by metal-ion-catalyzed σ-bond rearrangement.^[2][3] Similar reactions are known for homocubane (C₉H₁₀) and bishomocubane (C₁₀H₁₂).^[4][5]

Synthesis of cuneane from cubane

Cuneane

Ball and stick model of cuneane (1R,2R,3S,4S,5S,6R,7R,8S)
Names
Preferred IUPAC name Pentacyclo[3.3.0.02,4.03,7.06,8]octane
Identifiers
CAS Number	20656-23-9 Y
3D model (JSmol)	Interactive image
ChemSpider	124127 Y
PubChem CID	140734
CompTox Dashboard (EPA)	DTXSID20942857
InChI InChI=1S/C8H8/c1-2-5(1)6-3-4(6)8(2)7(1)3/h1-8H Y Key: YIJMEXRVJPVGIY-UHFFFAOYSA-N Y
SMILES C12C3C4C3C5C1C2C45
Properties
Chemical formula	C8H8
Molar mass	104.152 g·mol−1
Density	1.578 g/ml
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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.^[6] 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.^[7][8]

Equivalent carbon atoms in cuneane

Derivatives

Some cuneane derivatives have liquid crystal properties.^[9]