cyclopentene

{{Chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 443549310

| Name = Cyclopentene

| ImageFileL1_Ref = {{chemboximage|correct|??}}

| ImageFileL1 = Cyclopentene-2D-skeletal.png

| ImageSizeL1 = 100px

| ImageNameL1 = Cyclopentene

| ImageFileR1 = Cyclopentene-3D-balls.png

| ImageSizeR1 = 100px

| ImageNameR1 = Ball-and-stick model of cyclopentene

| ImageFile2 = Cyclopentene-3D-vdW.png

| ImageSize2 = 120px

| ImageName2 = Space-filling model of cyclopentene

| PIN = Cyclopentene

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 8544

| PubChem = 8882

| ChEMBL_Ref = {{ebicite|changed|EBI}}

| ChEMBL = 1797299

| InChI = 1/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2

| InChIKey = LPIQUOYDBNQMRZ-UHFFFAOYAS

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = LPIQUOYDBNQMRZ-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 142-29-0

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = ONM2CKV81Z

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 49155

| SMILES = C1CC=CC1

}}

|Section2={{Chembox Properties

| Formula = {{chem2|C5H8}}

| MolarMass = 68.11 g/mol

| Density = 0.771 g/cm³

| MeltingPtC = -135

| BoilingPtC = 44 to 46

}}

|Section7={{Chembox Hazards

| FlashPtC = -29

| NFPA-H = 1

| NFPA-F = 3

| NFPA-R = 1

}}

|Section8={{Chembox Related

| OtherCompounds = Cyclopentadiene
Cyclobutene

}}

Cyclopentene is a chemical compound with the formula {{chem2|(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%.{{Ullmann|author=Dieter Hönicke|author2=Ringo Födisch|author3=Peter Claus|author4=Michael Olson|title=Cyclopentadiene and Cyclopentene|year=2002|doi=10.1002/14356007.a08_227}}{{cite web |title=Hydrocarbon Composition of Gasoline Vapor Emissions from Enclosed Fuel Tanks |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100GPED.TXT |website=nepis.epa.gov |publisher=United States Environmental Protection Agency |date=2011}} 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 ({{Langx|de|Pentamethenylen}}).{{Cite journal |last=Gärtner |first=Carl |date=January 1893 |title=Das Pentamethenylen und sein Dibromür |url=https://books.google.com/books?id=QpEBhiH9p4QC&pg=PA331 |journal=Justus Liebigs Annalen der Chemie |language=en |volume=275 |issue=2-3 |pages=331–332 |doi=10.1002/jlac.18932750217 |issn=0075-4617}}

Cyclopentene is produced industrially in large amounts by steam cracking of naphtha. In the laboratory, it is prepared by dehydration of cyclopentanol.{{cite journal |doi=10.15227/orgsyn.019.0036|title=Cyclohexylbenzene|journal=Organic Syntheses|year=1939|volume=19|page=36|author=B. B. Corson, V. N. Ipatieff}} Substituted cyclopentenes are the product of the vinylcyclopropane-cyclopentene rearrangement.{{cite journal|doi=10.1021/cr010020z|title=Thermal Rearrangements of Vinylcyclopropanes to Cyclopentenes|year=2003|last1=Baldwin|first1=John E.|journal=Chemical Reviews|volume=103|pages=1197–212|issue=4|pmid=12683781}}

It can also be produced by the catalytic hydrogenation of cyclopentadiene.D. Hönicke, R. Födisch, P. Claus, M. Olson: Cyclopentadiene and Cyclopentene, in: Ullmanns Enzyklopädie der Technischen Chemie 2002, Wiley-VCH, Weinheim.

314px

Reactions

The polymerization of cyclopentene by Ziegler-Natta catalysts yields 1,3-linkages, not the more typical 1,2-linked polymer.{{cite journal|title=The microstructure of poly(cyclopentene) produced by polymerization of cyclopentene with homogeneous Ziegler-Natta catalysts|author=Collins, Scott|author2=Kelly, W. Mark|journal=Macromolecules|year=1992|volume=25|issue=1|page=233–7|doi=10.1021/ma00027a039|bibcode=1992MaMol..25..233C}}

Palladium-catalyzed hydrocarboxylation of cyclopentene gives cyclopentanecarboxylic acid:{{cite journal |doi=10.1002/anie.201908451|title=Synthesis of Carboxylic Acids by Palladium‐Catalyzed Hydroxycarbonylation |year=2019 |last1=Sang |first1=Rui |last2=Kucmierczyk |first2=Peter |last3=Dühren |first3=Ricarda |last4=Razzaq |first4=Rauf |last5=Dong |first5=Kaiwu |last6=Liu |first6=Jie |last7=Franke |first7=Robert |last8=Jackstell |first8=Ralf |last9=Beller |first9=Matthias |journal=Angewandte Chemie International Edition |volume=58 |issue=40 |pages=14365–14373 |pmid=31390131 |s2cid=199466915 |doi-access=free }}

:{{chem2|C5H8 + CO + H2O -> C5H9CO2H}}

References

External links

{{Commonscatinline|Cyclopentene}}

Category:Monomers