Propiolaldehyde

Propiolaldehyde
Names

Preferred IUPAC name Prop-2-ynal
Other names Propynal; Propiolic aldehyde
Identifiers
CAS Number	624-67-9^Y
3D model (JSmol)	Interactive image
ChemSpider	11721
ECHA InfoCard	100.009.871
PubChem CID	12222
UNII	SJ8A65XF7N^Y
CompTox Dashboard (EPA)	DTXSID3060790
SMILES C#CC=O
Properties
Chemical formula	C₃H₂O
Molar mass	54.048 g·mol⁻¹
Appearance	colorless liquid
Density	0.9152 g/cm³
Boiling point	54–57 °C (129–135 °F; 327–330 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Propiolaldehyde is an organic compound with molecular formula HC₂CHO. It is the simplest chemical compound containing both alkyne and aldehyde functional groups. It is a colorless liquid with explosive properties.^[1]

Reactions

The compound exhibits reactions expected for an electrophilic alkynyl aldehyde. It is a dienophile and a good Michael acceptor. Grignard reagents add to the carbonyl center.^[1] Its explosive properties are attributed to the exothermicity of its polymerization.^[1]

Preparation

Its acetal can be prepared from acrolein.^[2]

Occurrence in interstellar medium

Propynal has been observed in the interstellar medium. It is hypothesized to be formed from a carbon monoxide-acetylene complex.^[3] Another possible pathway is through the reaction of propynylidyne (C₃H) with water.^[4]

Hazards

The compound is explosive, possibly because it tends to polymerize.^[1]

References

^ ^a ^b ^c ^d P. Perlmutter (2001). "Propargyl Aldehyde". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rp262m. ISBN 978-0471936237.
^ A. Le Coq and A. Gorgues (1979). "Alkyness via Phase Transfer-Catalyzed Dehydrohalogenatiion: Propiolaldehyde Diethyl Acetal". Organic Syntheses. 59: 10. doi:10.15227/orgsyn.059.0010.
^ Zhou, Li; Ralf I. Kaiser (2008), "Pathways to Oxygen-Bearing Molecules in the Interstellar Medium and in Planetary Atmospheres: Cyclopropenone (c-C3H2O) and Propynal (HCCCHO)", The Astrophysical Journal, 686 (2), doi:10.1086/591072
^ Xie, Hong-bin; Chang-bin Shao (2007), "Radical-Molecule Reaction C3H + H2O on Amorphous Water Ice: A Promising Route for Interstellar Propynal", The Astrophysical Journal, 670 (1): 449–456, doi:10.1086/520757

Molecules detected in outer space

Molecules

Diatomic	Aluminium monochloride Aluminium monofluoride Aluminium(II) oxide Argonium Carbon cation Carbon monophosphide Carbon monosulfide Carbon monoxide Cyano radical Diatomic carbon Fluoromethylidynium Helium hydride ion Hydrogen chloride Hydrogen fluoride Hydrogen (molecular) Hydroxyl radical Iron(II) oxide Magnesium monohydride Methylidyne radical Nitric oxide Nitrogen (molecular) Imidogen Sulfur mononitride Oxygen (molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfur monohydride Sulfur monoxide Titanium(II) oxide
Triatomic	Aluminium(I) hydroxide Aluminium isocyanide Amino radical Carbon dioxide Carbonyl sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide (HCN) Hydrogen isocyanide (HNC) Hydrogen sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene radical N₂H⁺ Nitrous oxide Nitroxyl Ozone Phosphaethyne Potassium cyanide Protonated molecular hydrogen Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water
Four atoms	Acetylene Ammonia Cyanic acid Cyanoethynyl Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl cation Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon monoxide Tricarbon monosulfide Thiocyanic acid
Five atoms	Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Silane Silicon-carbide cluster
Six atoms	Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC<sub>4</sub>N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene
Seven atoms	Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Glycolonitrile Hexatriynyl radical Methylacetylene Methylamine Methyl isocyanate Vinyl alcohol
Eight atoms	Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Hexapentaenylidene Methylcyanoacetylene Methyl formate Propenal
Nine atoms	Acetamide Cyanohexatriyne Cyanotriacetylene Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Propionitrile
Ten atoms or more	Acetone Benzene Benzonitrile Buckminsterfullerene (C₆₀, C₆₀⁺, fullerene, buckyball) C₇₀ fullerene Cyanodecapentayne Cyanopentaacetylene Cyanotetra-acetylene Ethylene glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propanal n-Propyl cyanide Pyrimidine Heptatrienyl radical