Propadiene

Quality 0.50 · 2 views · Updated 2 months ago

1=Organic compound (H2C=C=CH2)

title: "Propadiene" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["fuel-gas", "alkadienes", "cumulated-dienes"] description: "1=Organic compound (H2C=C=CH2)" topic_path: "general/fuel-gas" source: "https://en.wikipedia.org/wiki/Propadiene" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary 1=Organic compound (H2C=C=CH2) ::

| Verifiedimages = changed | Watchedfields = changed | verifiedrevid = 464215747 | ImageFileL1 = Propadiene structure.svg | ImageFileL1_Ref = | ImageNameL1 = Stereo structural formula of propadiene with explicit hydrogens | ImageFileR1 = Allene3D.png | ImageFileR1_Ref = | ImageNameR1 = Spacefill model of propadiene | ImageFile2 = Allene-CRC-IR-3D-balls.png | ImageFile2_Ref = | ImageSize2 = 160 | ImageName2 = Ball and stick model of propadiene | PIN = Propa-1,2-diene | SystematicName = Propadiene | OtherNames = | IUPACName = Allene | Section1 = {{Chembox Identifiers | CASNo = 463-49-0 | CASNo_Ref = | UNII_Ref = | UNII = 4AV0LZ8QKB | PubChem = 10037 | ChemSpiderID = 9642 | ChemSpiderID_Ref = | EINECS = 207-335-3 | UNNumber = 2200 | MeSHName = Propadiene | ChEBI_Ref = | ChEBI = 37601 | ChEMBL = 116960 | ChEMBL_Ref = | Beilstein = 1730774 | Gmelin = 860 | SMILES = C=C=C | StdInChI = 1S/C3H4/c1-3-2/h1-2H2 | StdInChI_Ref = | StdInChIKey = IYABWNGZIDDRAK-UHFFFAOYSA-N | StdInChIKey_Ref = | Section2 = {{Chembox Properties | C=3 | H=4 | Appearance = Colorless gas | MeltingPtC = -136 | BoilingPtC = -34 | LogP = 1.45}} | Section3 = {{Chembox Hazards | ExternalSDS = External MSDS | GHSPictograms = | GHSSignalWord = Danger | HPhrases = | PPhrases = | NFPA-H = 0 | NFPA-F = 4 | NFPA-R = 3 | ExploLimits = 13%}}

Propadiene () or allene () is the organic compound with the formula . It is the simplest allene, i.e. a compound with two adjacent carbon double bonds. As a constituent of MAPP gas, it has been used as a fuel for specialized welding.

Production and equilibrium with methylacetylene

Propadiene exists in equilibrium with methylacetylene (propyne) and the mixture is sometimes called MAPD for methylacetylene-propadiene: : for which at 270 °C or 0.1 at 5 °C.

MAPD is produced as a side product, often an undesirable one, of dehydrogenation of propane to produce propene, an important feedstock in the chemical industry. MAPD interferes with the catalytic polymerization of propene.

Occurrence in Space

In 2019 it was announced that propadiene had been detected in the atmosphere of Saturn's moon Titan using the NASA Infrared Telescope Facility. This was the first time that propadiene had been detected in space, and the second structural isomeric pair (paired with propyne) detected in Titan's atmosphere, after HCN-HNC.

References

References

  1. (2014). "Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book)". [[Royal Society of Chemistry.
  2. https://www.ebi.ac.uk/chebi/CHEBI:37601
  3. {{GESTIS
  4. "allenes".
  5. Klaus Buckl, Andreas Meiswinkel "Propyne" in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2008, Wiley-VCH, Weinheim. {{doi. 10.1002/14356007.m22_m01
  6. (2019-08-20). "Detection of Propadiene on Titan". The Astrophysical Journal Letters.
  7. (December 2011). "First detection of hydrogen isocyanide (HNC) in Titan's atmosphere". Astronomy & Astrophysics.
  8. (May 2012). "Neutral production of hydrogen isocyanide (HNC) and hydrogen cyanide (HCN) in Titan's upper atmosphere". Astronomy & Astrophysics.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

fuel-gasalkadienescumulated-dienes