Cyclopentene

Cyclopentene
Cyclopentene
Cyclopentene
Ball-and-stick model of cyclopentene
Ball-and-stick model of cyclopentene
Space-filling model of cyclopentene
Names
Preferred IUPAC name
Cyclopentene
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.005.030 Edit this at Wikidata
UNII
  • InChI=1S/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2 checkY
    Key: LPIQUOYDBNQMRZ-UHFFFAOYSA-N checkY
  • InChI=1/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2
    Key: LPIQUOYDBNQMRZ-UHFFFAOYAS
  • C1CC=CC1
Properties
C5H8
Molar mass 68.11 g/mol
Density 0.771 g/cm3
Melting point −135 °C (−211 °F; 138 K)
Boiling point 44 to 46 °C (111 to 115 °F; 317 to 319 K)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
3
1
Flash point −29 °C (−20 °F; 244 K)
Related compounds
Related compounds
 Cyclopentadiene
Cyclobutene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Cyclopentene is a chemical compound with the formula (CH2)3(CH)2. It is a colorless liquid with a petrol-like odor. It has few applications, and thus is mainly used as a minor component of gasoline, present in concentrations of less than 1%.[1][2] It is one of the principal cycloalkenes.

History and synthesis

Cyclopentene was first prepared by Carl Gärtner in 1893 from iodocyclopentane with potassium hydroxide. He named it pentamethenylene (German: Pentamethenylen).[3]

Cyclopentene is produced industrially in large amounts by steam cracking of naphtha. In the laboratory, it is prepared by dehydration of cyclopentanol.[4] Substituted cyclopentenes are the product of the vinylcyclopropane-cyclopentene rearrangement.[5]

It can also be produced by the catalytic hydrogenation of cyclopentadiene.[6]

Reactions

The polymerization of cyclopentene by Ziegler-Natta catalysts yields 1,3-linkages, not the more typical 1,2-linked polymer.[7]

Palladium-catalyzed hydrocarboxylation of cyclopentene gives cyclopentanecarboxylic acid:[8]

C5H8 + CO + H2O → C5H9CO2H

References

  1. ^ Dieter Hönicke; Ringo Födisch; Peter Claus; Michael Olson (2002). "Cyclopentadiene and Cyclopentene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_227. ISBN 978-3527306732.
  2. ^ "Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks". nepis.epa.gov. United States Environmental Protection Agency. 2011.
  3. ^ Gärtner, Carl (January 1893). "Das Pentamethenylen und sein Dibromür". Justus Liebigs Annalen der Chemie. 275 (2–3): 331–332. doi:10.1002/jlac.18932750217. ISSN 0075-4617.
  4. ^ B. B. Corson, V. N. Ipatieff (1939). "Cyclohexylbenzene". Organic Syntheses. 19: 36. doi:10.15227/orgsyn.019.0036.
  5. ^ Baldwin, John E. (2003). "Thermal Rearrangements of Vinylcyclopropanes to Cyclopentenes". Chemical Reviews. 103 (4): 1197–212. doi:10.1021/cr010020z. PMID 12683781.
  6. ^ D. Hönicke, R. Födisch, P. Claus, M. Olson: Cyclopentadiene and Cyclopentene, in: Ullmanns Enzyklopädie der Technischen Chemie 2002, Wiley-VCH, Weinheim.
  7. ^ Collins, Scott; Kelly, W. Mark (1992). "The microstructure of poly(cyclopentene) produced by polymerization of cyclopentene with homogeneous Ziegler-Natta catalysts". Macromolecules. 25 (1): 233–7. Bibcode:1992MaMol..25..233C. doi:10.1021/ma00027a039.
  8. ^ Sang, Rui; Kucmierczyk, Peter; Dühren, Ricarda; Razzaq, Rauf; Dong, Kaiwu; Liu, Jie; Franke, Robert; Jackstell, Ralf; Beller, Matthias (2019). "Synthesis of Carboxylic Acids by Palladium‐Catalyzed Hydroxycarbonylation". Angewandte Chemie International Edition. 58 (40): 14365–14373. doi:10.1002/anie.201908451. PMID 31390131. S2CID 199466915.
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