Cyclohexene is a
hydrocarbon
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 Hydrophobe, hydrophobic; their odor is usually fain ...
with the formula . It is a
cycloalkene
In organic chemistry, a cycloalkene or cycloolefin is a type of alkene hydrocarbon which contains a closed Ring (chemistry), ring of carbon atoms and either one or more double bonds, but has no Aromaticity, aromatic character. Some cycloalkenes, ...
. At room temperature, cyclohexene is a colorless
liquid
Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...
with a sharp odor. Among its uses, it is an
intermediate in the commercial synthesis of
nylon
Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups.
Nylons are generally brownish in color and can possess a soft texture, with some varieti ...
.
Production and uses
Cyclohexene is produced by the partial
hydrogenation
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 redox, reduce or Saturated ...
of
benzene
Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...
, a process developed by the
Asahi Chemical company. The main product of the process is cyclohexane because cyclohexene is more easily hydrogenated than benzene.
In the laboratory, it can be prepared by
dehydration
In physiology, dehydration is a lack of total body water that disrupts metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of water. Mild deh ...
of
cyclohexanol.
:
Reactions and uses
Benzene is converted to
cyclohexylbenzene by acid-catalyzed alkylation with cyclohexene. Cyclohexylbenzene is a precursor to both phenol and cyclohexanone.
Hydration of cyclohexene gives
cyclohexanol, which can be
dehydrogenated to give
cyclohexanone, a precursor to
caprolactam.
The
oxidative cleavage of cyclohexene gives
adipic acid
Adipic acid or hexanedioic acid is the organic compound with the formula C6H10O4. It a white crystalline powder at standard temperature and pressure. From an industrial perspective, it is the most important dicarboxylic acid at about 2.5 billion ...
.
Hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...
is used as the oxidant in the presence of a tungsten catalyst.
1,5-Hexadiene is produced by
ethenolysis of cyclohexene. Bromination gives 1,2-dibromocyclohexane.
Structure
Cyclohexene is most stable in a half-chair
conformation,
unlike the preference for a chair form of
cyclohexane
Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexan ...
. One basis for the
cyclohexane conformational preference for a chair is that it allows each bond of the ring to adopt a
staggered conformation. For cyclohexene, however, the alkene is planar, equivalent to an eclipsed conformation at that bond.
See also
*
Diels-Alder reaction
*
Cyclohexa-1,3-diene
*
Cyclohexa-1,4-diene
References
External links
*
*
Material Safety Data Sheet for cyclohexene*
ttp://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0183 Cyclohexene synthesisData sheet at inchem.org
{{cycloalkenes
Cycloalkenes
Hydrocarbon solvents