Cyclopentene is a
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one ele ...
with the formula . It is a colorless
liquid
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, an ...
with a
petrol
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic c ...
-like
odor
An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...
. It has few applications, and thus is mainly used as a minor component of gasoline, present in concentrations of less than 1%. It is one of the principal
cycloalkene
A cycloalkene or cycloolefin is a type of alkene hydrocarbon which contains a closed ring of carbon atoms and either one or more double bonds, but has no aromatic character. Some cycloalkenes, such as cyclobutene and cyclopentene, can be used as mo ...
s.
Production
Cyclopentene is produced industrially in large amounts by
steam cracking
Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. It is the principal industrial method for producing the lighter alkenes (or commonly olefins), including e ...
of
naphtha
Naphtha ( or ) is a flammable liquid hydrocarbon mixture.
Mixtures labelled ''naphtha'' have been produced from natural gas condensates, petroleum distillates, and the distillation of coal tar and peat. In different industries and regions ...
. In the laboratory, it is prepared by dehydration of
cyclopentanol
Cyclopentanol or cyclopentyl alcohol is a cyclic alcohol. It is also known as hydroxycyclopentane.
Reactions
The dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. ...
.
It can also produced by the
catalytic hydrogenation of
cyclopentadiene
Cyclopentadiene is an organic compound with the formula C5H6.LeRoy H. Scharpen and Victor W. Laurie (1965): "Structure of cyclopentadiene". ''The Journal of Chemical Physics'', volume 43, issue 8, pages 2765-2766. It is often abbreviated CpH beca ...
.
[D. Hönicke, R. Födisch, P. Claus, M. Olson: ''Cyclopentadiene and Cyclopentene'', in: '' Ullmanns Enzyklopädie der Technischen Chemie'' 2002, Wiley-VCH, Weinheim.]
Use in mechanistic organic chemistry
Cyclopentene is used in analysing the mechanisms of organic reactions. It can be obtained from vinylcyclopropane in the
vinylcyclopropane-cyclopentene rearrangement.
The polymerization of cyclopentene by
Ziegler-Natta catalysts yields 1,3-linkages, not the more typical 1,2-linked polymer.
References
External links
*
{{Authority control
Monomers