Cyclopropenone
{{Chembox
| ImageFile = Cyclopropenone.svg
| ImageSize = 120px
| ImageFile1 = C3H2OResonance.png
| ImageFile2 = Cyclopropenone-3D-vdW.png
| ImageCaption1 = Main resonance structures of cyclopropenone.
| PIN = Cycloprop-2-en-1-one
| OtherNames = Cyclopropenone, Cyclopropene-3-one
| Section1 = {{Chembox Identifiers
| CASNo = 2961-80-0
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 5MPZ6QZ6ZF
| PubChem = 137779
| ChemSpiderID = 121433
| SMILES = c1cc1=O
| InChI = 1/C3H2O/c4-3-1-2-3/h1-2H
| InChIKey = GGRQLKPIJPFWEZ-UHFFFAOYAI
| StdInChI = 1S/C3H2O/c4-3-1-2-3/h1-2H
| StdInChIKey = GGRQLKPIJPFWEZ-UHFFFAOYSA-N
}}
| Section2 = {{Chembox Properties
| C=3|H=2|O=1
| Appearance = Colorless liquid
| MeltingPtC = −29 to −28
}}
}}
Cyclopropenone is an organic compound with molecular formula {{chem2|C3H2O}} consisting of a cyclopropene carbon framework with a ketone functional group. It is a colorless, volatile liquid that boils near room temperature.R. Breslow, J. Pecoraro, T. Sugimoto "Cyclpropenone" Org. Synth. 1977, vol. 57, pp. 41. {{doi|10.15227/orgsyn.057.0041}} Neat cyclopropenone polymerizes upon standing at room temperature,{{Cite journal|last1=Breslow|first1=Ronald|last2=Oda|first2=Masaji|date=1972-06-01|title=Isolation and characterization of pure cyclopropenone|journal=Journal of the American Chemical Society|volume=94|issue=13|pages=4787–4788|doi=10.1021/ja00768a089|issn=0002-7863}} and chemical vendors typically supply it as an acetal.{{cite encyclopedia|doi=10.1002/047084289X.rn00486|entry=Cyclopropene, 3,3‑Dimethoxy|first1=Gregory I.|last1=Elliott|first2=Dale L.|last2=Boger|encyclopedia=Encyclopedia of Reagents for Organic Synthesis|quote=Dimethyl cyclopropenone ketal is less stable than the corresponding cyclic ketal derivatives....A direct route to cyclopropenone is the hydrolysis of 3,3{{nbh}}dimethoxycyclopropene.}} The chemical properties of the compound are dominated by the strong polarization of the carbonyl group, which gives a partial positive charge with aromatic stabilization on the ring and a partial negative charge on oxygen. It is an aromatic compound.{{cite journal |title= Experiments show cyclopropenone is aromatic |journal= Chem. Eng. News |year= 1983 |volume= 61 |issue= 38 |pages= 33 |doi= 10.1021/cen-v061n038.p033 }}{{cite journal |title= Poly(cyclopropenone)s: Formal Inclusion of the Smallest Hückel Aromatic into π-Conjugated Polymers |first1= Patricia A. |last1= Peart|first2= John D. |last2= Tovar |journal= J. Org. Chem. |year= 2010 |volume= 76 |issue= 15 |pages= 5689–5696 |doi= 10.1021/jo101108f |pmid= 20704438 }}