Pentenes (amylene) - the general name for unsaturated hydrocarbons of the homologous series of alkenes with the chemical formula C 5 H 10 .
Building
In total, pentenes include 6 isomers, including cis and trans isomers :
- penten-1 (α-amylene) CH 2 = CH-CH 2 -CH 2 -CH 3
- cis- penten-2 ( cis- β-amylene) CH 3 -CH = CH-CH 2 -CH 3
- transpenten-2 ( trans- β-amylene) CH 3 -CH = CH-CH 2 -CH 3
- 2-methylbutene-1 (γ-isoamylene) CH 2 = C (CH 3 ) -CH 2 -CH 3
- 3-methylbutene-1 (α-isoamylene) CH 2 = CH-CH (CH 3 ) -CH 3
- 2-methylbutene-2 (β-isoamylene) CH 3 -CH = C (CH 3 ) -CH 3
Pentene in its molecular structure has one double bond . 1-pentene and 2-pentene differ in the location of the covalent bond - in the first or second carbon-carbon double bonds. 1-pentene is an alpha olefin .
Properties
Pentenes are low-boiling liquids, insoluble in water, but soluble in organic solvents. The melting point is in the range from -168.5 ° C (3-methylbutene-1) to -137.56 (2-methylbutene-1), the boiling point varies from 20.06 ° C (3-methylbutene-1) to 38 , 57 ° C (2-methylbutene-2).
Pentenes possess all the properties of alkenes.
Getting
Most often, 1-pentene is formed as a by-product of catalytic or thermal cracking of oil or as a by-product of the production of ethylene or propylene by thermal cracking of hydrocarbon fractions .
1-Pentene is unusually stable as a component of the mixture. Therefore, it is mixed with other hydrocarbons and is used to produce gasoline by alkylation with isobutane .
The only commercial manufacturer of 1-pentene, a double-bonded alkene at the end of the linear chain, is the South African petrochemical company Sasol Ltd , which extracts it from crude oil using the Fischer-Tropsch synthesis process .
Literature
- Chemical Encyclopedia / Editorial Board: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1992. - T. 3 (Med-Paul). - 639 p. - ISBN 5-82270-039-8 .