Cyclooctane

{{#if:112.21 g/molC₈H₁₆0.834 g/cm³14.59 °C149 °C7.90 mg/L|! style="background: #F8EABA; text-align: center;" colspan="2" | Properties

Cyclooctane
File:Regular octagon.svg
Identifiers
CAS number	292-64-8 7pxY
PubChem	9266
ChemSpider	8909 7pxY
ChEMBL	CHEMBL452651 7pxY
Jmol-3D images	Image 1
SMILES C1CCCCCCC1 <p><p style="word-wrap: break-word;">
InChI InChI=1S/C8H16/c1-2-4-6-8-7-5-3-1/h1-8H2 7pxY Key: WJTCGQSWYFHTAC-UHFFFAOYSA-N 7pxY InChI=1/C8H16/c1-2-4-6-8-7-5-3-1/h1-8H2 Key: WJTCGQSWYFHTAC-UHFFFAOYAO
Molecular formula	C8H16
Molar mass	112.21 g/mol
Density	0.834 g/cm3
Melting point	14.59 °C
Boiling point	149 °C
Solubility in water	7.90 mg/L
Related compounds
Related cycloalkanes	Cycloheptane
14pxY (verify) (what is: 10pxY/10pxN?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cyclooctane is a cycloalkane with the molecular formula (CH₂)₈. It is a simple colourless hydrocarbon, but it is often a reference compound for saturated eight-membered ring compounds in general.

Conformation

The conformation has been studied extensively using computational methods. Hendrickson noted that "cyclooctane is unquestionably the conformationally most complex cycloalkane owing to the existence of many conformers of comparable energy." The boat-chair conformation I is the most stable form. This conformation was confirmed by Allinger and co-workers. The crown conformation II is slightly less stable. Among the many compounds exhibiting the crown conformation (structure II) is S₈, elemental sulfur.

<center>400px
160px	160px
<center>Boat-chair conformation	Crown conformation

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Synthesis and reactions

The main route to cyclooctane derivatives involves the dimerization of butadiene, catalysed by nickel(0) complexes such as nickel bis(cyclooctadiene). This process affords, among other products, 1,5-cyclooctadiene (COD), which can be hydrogenated. COD is widely used for the preparation of precatalysts for homogeneous catalysis. The activation of these catalysts under H2, produces cyclooctane, which is usually discarded or burnt:

C₈H₁₂ + 2 H₂ → C₈H₁₆

Cyclooctane participates in no reactions except those typical of a other saturated hydrocarbons, combustion and free radical halogenation. Recent work on alkane functionalisation, using peroxides such as dicumyl peroxide, has opened up the chemistry to some extent, allowing for example the introduction of a phenylamino group.

File:CyclooctaneAmination.png

Amination of cyclooctane by nitrobenzene

References

cs:Cyklooktan