Cyclooctane

Last updated
Cyclooctane
Regular octagon.svg
Names
Preferred IUPAC name
Cyclooctane
Other names
Cyclo-octane
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.005.484 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C8H16/c1-2-4-6-8-7-5-3-1/h1-8H2 Yes check.svgY
    Key: WJTCGQSWYFHTAC-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C8H16/c1-2-4-6-8-7-5-3-1/h1-8H2
    Key: WJTCGQSWYFHTAC-UHFFFAOYAO
  • C1CCCCCCC1
Properties
C8H16
Molar mass 112.21 g/mol
Density 0.834 g/cm3
Melting point 14.59 °C (58.26 °F; 287.74 K)
Boiling point 149 °C (300 °F; 422 K)
7.90 mg/L
−91.4·10−6 cm3/mol
Related compounds
Related cycloalkanes
Cycloheptane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Cyclooctane is a cycloalkane with the molecular formula (CH2)8. [1] It is a simple colourless hydrocarbon, but it is often a reference compound for saturated eight-membered ring compounds in general.

Contents

Cyclooctane has a camphoraceous odor. [2]

Conformations

The conformation of cyclooctane 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 (below) is the most stable form. [3] This conformation was confirmed by Allinger and co-workers. [4] The crown conformation (below) [5] is slightly less stable. Among the many compounds exhibiting the crown conformation (structure II) is S8, elemental sulfur.

Cyclooctane boat-chair conformation.svg Cyclooctane-boat-chair-3D-balls.png Cyclooctane crown conformation.svg Cyclooctane-crown-3D-balls.png
Boat-chair [6] Crown [6]
Cyclooctane tub conformation.svg Cyclooctane boat-boat conformation.svg Cyclooctane twist boat-chair conformation.svg Cyclooctane twist chair-chair conformation.svg
Tub [7] Boat-boat [6] Twist boat-chair [6] Twist chair-chair [6]

Synthesis and reactions

The main route to cyclooctane derivatives involves the dimerization of butadiene, catalysed by nickel(0) complexes such as nickel bis(cyclooctadiene). [8] 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 other saturated hydrocarbons, combustion and free radical halogenation. Work in 2009 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. [9]

Amination of cyclooctane by nitrobenzene CyclooctaneAmination.png
Amination of cyclooctane by nitrobenzene

Related Research Articles

Alkane Type of chemical compound

In organic chemistry, an alkane, or paraffin, is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula CnH2n+2. The alkanes range in complexity from the simplest case of methane, where n = 1, to arbitrarily large and complex molecules, like pentacontane or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane.

Alkene Hydrocarbon compound containing one or more carbon-carbon double bonds

In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond.

Diene Covalent compound that contains two double bonds

In organic chemistry a diene is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alkene units, with the standard prefix di of systematic nomenclature. As a subunit of more complex molecules, dienes occur in naturally occurring and synthetic chemicals and are used in organic synthesis. Conjugated dienes are widely used as monomers in the polymer industry. Polyunsaturated fats are of interest to nutrition.

Hydrocarbon Organic compound consisting entirely of hydrogen and carbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic with only weak odours. Because of their diverse molecular structures, it is difficult to generalize further. In the oil & gas industry, hydrocarbon is a generalised term, which combines petroleum and natural gas as the two naturally occurring phases of hydrocarbon commoditised by the sector. Most anthropogenic emissions of greenhouse gases are from the burning of fossil fuels including fuel production and combustion. Natural sources of hydrocarbons such as ethylene, isoprene, and monoterpenes come from the emissions of vegetation.

Cycloalkane

In organic chemistry, the cycloalkanes are the monocyclic saturated hydrocarbons. In other words, a cycloalkane consists only of hydrogen and carbon atoms arranged in a structure containing a single ring, and all of the carbon-carbon bonds are single. The larger cycloalkanes, with more than 20 carbon atoms are typically called cycloparaffins. All cycloalkanes are isomers of alkenes.

Hydrogenation Chemical reaction between molecular hydrogen and another compound or element

Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, often an alkene. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogenation reduces double and triple bonds in hydrocarbons.

Cyclohexane is a cycloalkane with the molecular formula C6H12. Cyclohexane is non-polar. Cyclohexane is a colorless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexane is mainly used for the industrial production of adipic acid and caprolactam, which are precursors to nylon.

Alicyclic compound Organic molecule with one or more non-aromatic all-carbon rings

In organic chemistry, an alicyclic compound contains one or more all-carbon rings which may be either saturated or unsaturated, but do not have aromatic character. Alicyclic compounds may have one or more aliphatic side q attached.

Chirality (chemistry) Geometric property of some molecules and ions

In chemistry, a molecule or ion is called chiral if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality. The terms are derived from Ancient Greek χείρ (cheir) 'hand'; which is the canonical example of an object with this property.

Conformational isomerism Different molecular structures formed only by rotation about single bonds

In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted just by rotations about formally single bonds. While any two arrangements of atoms in a molecule that differ by rotation about single bonds can be referred to as different conformations, conformations that correspond to local minima on the potential energy surface are specifically called conformational isomers or conformers. Conformations that correspond to local maxima on the energy surface are the transition states between the local-minimum conformational isomers. Rotations about single bonds involve overcoming a rotational energy barrier to interconvert one conformer to another. If the energy barrier is low, there is free rotation and a sample of the compound exists as a rapidly equilibrating mixture of multiple conformers; if the energy barrier is high enough then there is restricted rotation, a molecule may exist for a relatively long time period as a stable rotational isomer or rotamer. When the time scale for interconversion is long enough for isolation of individual rotamers, the isomers are termed atropisomers. The ring-flip of substituted cyclohexanes constitutes another common form of conformational isomerism.

Cyclooctatetraene Chemical compound

1,3,5,7-Cyclooctatetraene (COT) is an unsaturated derivative of cyclooctane, with the formula C8H8. It is also known as [8]annulene. This polyunsaturated hydrocarbon is a colorless to light yellow flammable liquid at room temperature. Because of its stoichiometric relationship to benzene, COT has been the subject of much research and some controversy.

Tetrahedral molecular geometry Central atom with four substituents located at the corners of a tetrahedron

In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1(−13) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane as well as its heavier analogues. Methane and other perfectly symmetrical tetrahedral molecules belong to point group Td, but most tetrahedral molecules have lower symmetry. Tetrahedral molecules can be chiral.

Cycloocta-1,5-diene is a cyclic hydrocarbon with the chemical formula C8H12; specifically [–(CH
2
)
2
–CH=CH–]2.

Organonickel chemistry

Organonickel chemistry is a branch of organometallic chemistry that deals with organic compounds featuring nickel-carbon bonds. They are used as a catalyst, as a building block in organic chemistry and in chemical vapor deposition. Organonickel compounds are also short-lived intermediates in organic reactions. The first organonickel compound was nickel tetracarbonyl Ni(CO)4, reported in 1890 and quickly applied in the Mond process for nickel purification. Organonickel complexes are prominent in numerous industrial processes including carbonylations, hydrocyanation, and the Shell higher olefin process.

<i>trans</i>-Cyclooctene Chemical compound

trans-Cyclooctene is a cyclic hydrocarbon with the formula [–(CH2)6CH=CH–], where the two C–C single bonds adjacent to the double bond are on opposite sides of the latter's plane. It is a colorless liquid with a disagreeable odor.

Bis(cyclooctadiene)nickel(0) Chemical compound

Bis(cyclooctadiene)nickel(0) is the organonickel compound with the formula Ni(C8H12)2, also written Ni(cod)2. It is a diamagnetic coordination complex featuring tetrahedral nickel(0) bound to the alkene groups in two 1,5-cyclooctadiene ligands. This highly air-sensitive yellow solid is a common source of Ni(0) in chemical synthesis.

Twistane (IUPAC name: tricyclo[4.4.0.03,8]decane) is an organic compound with the formula C10H16. It is a cycloalkane and an isomer of the simplest diamondoid, adamantane, and like adamantane, is not very volatile. Twistane was named for the way its rings are permanently forced into the cyclohexane conformation known as the "twist-boat". The compound was first reported by Whitlock in 1962.

Organoiron chemistry is the chemistry of iron compounds containing a carbon-to-iron chemical bond. Organoiron compounds are relevant in organic synthesis as reagents such as iron pentacarbonyl, diiron nonacarbonyl and disodium tetracarbonylferrate. While iron adopts oxidation states from Fe(−II) through to Fe(VII), Fe(IV) is the highest established oxidation state for organoiron species. Although iron is generally less active in many catalytic applications, it is less expensive and "greener" than other metals. Organoiron compounds feature a wide range of ligands that support the Fe-C bond; as with other organometals, these supporting ligands prominently include phosphines, carbon monoxide, and cyclopentadienyl, but hard ligands such as amines are employed as well.

Georgiy Borisovich Shul’pin was born in 1946 in Moscow, Russia. He graduated with a M.S. degree in chemistry from the Chemistry Department of Moscow State University in 1969. Between 1969 and 1972, he was a postgraduate student at the Nesmeyanov Institute of Organoelement Compounds under the direction of Prof. A. N. Nesmeyanov and received his Ph.D. in organometallic chemistry in 1975. He received his Dr. of Sciences degree in 2013.

Cyclooctadiene iridium chloride dimer Chemical compound

Cyclooctadiene iridium chloride dimer is an organoiridium compound with the formula [Ir(μ2-Cl)(COD)]2, where COD is the diene 1,5-cyclooctadiene (C8H12). It is an orange-red solid that is soluble in organic solvents. The complex is used as a precursor to other iridium complexes, some of which are used in homogeneous catalysis. The solid is air-stable but its solutions degrade in air.

References

  1. Mackay, Donald (2006). Handbook of Physical-chemical Properties and Environmental Fate for Organic Chemicals. CRC Press. p. 258. ISBN   978-1-56670-687-2.
  2. Sell, C. S. (2006). "On the Unpredictability of Odor". Angew. Chem. Int. Ed. 45 (38): 6254–6261. doi:10.1002/anie.200600782. PMID   16983730.
  3. Hendrickson, James B. (1967). "Molecular Geometry V. Evaluation of Functions and Conformations of Medium Rings". Journal of the American Chemical Society . 89 (26): 7036–7043. doi:10.1021/ja01002a036.
  4. Dorofeeva, O. V.; Mastryukov, V. S.; Allinger, N. L.; Almenningen, A. (1985). "The molecular structure and conformation of cyclooctane as determined by electron diffraction and molecular mechanics calculations". The Journal of Physical Chemistry. 89 (2): 252–257. doi:10.1021/j100248a015.
  5. IUPAC, Compendium of Chemical Terminology , 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006) "crown conformation". doi:10.1351/goldbook.C01422
  6. 1 2 3 4 5 Pakes, P. W.; Rounds, T. C.; Strauss, H. L. (1981). "Conformations of cyclooctane and some related oxocanes". The Journal of Physical Chemistry. 85 (17): 2469–2475. doi:10.1021/j150617a013. ISSN   0022-3654.
  7. Moss, G. P. (1996). "Basic terminology of stereochemistry (IUPAC Recommendations 1996)". Pure and Applied Chemistry. 68 (12): 2193–2222. doi:10.1351/pac199668122193. ISSN   0033-4545. S2CID   98272391.
  8. Thomas Schiffer, Georg Oenbrink, “Cyclododecatriene, Cyclooctadiene, and 4-Vinylcyclohexene” in Ullmann’s Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a08_205.
  9. Deng, Guojun; Wenwen Chen; Chao-Jun Li (February 2009). "An Unusual Peroxide-Mediated Amination of Cycloalkanes with Nitroarenes". Advanced Synthesis & Catalysis. 351 (3): 353–356. doi:10.1002/adsc.200800689.