Vinylacetylene
| Names | |
|---|---|
| Preferred IUPAC name
But-1-en-3-yne | |
Other names
| |
| Identifiers | |
3D model (JSmol)
|
|
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.010.650 |
PubChem CID
|
|
| UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| H2C=CH−C≡CH | |
| Molar mass | 52.07456 g/mol |
| Appearance | colourless gas |
| Boiling point | 0 to 6 °C (32 to 43 °F; 273 to 279 K) |
| low | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
|
Very flammable. Extremely dangerous because it can explode, even without air. |
| NFPA 704 (fire diamond) | |
| Flash point | < −5 °C (23 °F; 268 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
| |
Vinylacetylene is the organic compound with the formula C4H4 or H2C=CH−C≡CH. The colourless gas was once used in the polymer industry. It is composed of both alkyne and alkene groups and is the simplest enyne.
Safety
Vinylacetylene is extremely dangerous because in high enough concentrations (typically > 30 mole percent, but pressure dependent) it can auto-detonate (explode without air being present) especially at elevated pressures, such as those seen in chemical plants processing C4 hydrocarbons (hydrocarbons with 4 carbon atoms).[2] An example of such an explosion occurred at a Union Carbide plant in Texas City in 1969.[3]
Synthesis
Vinylacetylene was first synthesized by Hofmann elimination of the related quaternary ammonium salt:[4]
- [(CH3)3N+−CH2−CH=CH−CH2−N+(CH3)3](I−)2 → 2 [(CH3)3NH]+I− + H2C=CH−C≡CH
It is usually synthesized by dehydrohalogenation of 1,3-dichloro-2-butene Cl−CH2−CH=CCl−CH3.[5]
It also arises via the dimerization of acetylene, which is catalyzed by copper(I) chloride.[6]
Dehydrogenation of 1,3-butadiene is yet another route.
Application
At one time, chloroprene (2-chloro-1,3-butadiene), an industrially important monomer, was produced via the intermediacy of vinyl acetylene.[7] In this process, acetylene is dimerized to give vinyl acetylene, which is then combined with hydrogen chloride to give 4-chloro-1,2-butadiene via 1,4-addition. This allene derivative which, in the presence of cuprous chloride, rearranges to 2-chloro-1,3-butadiene:[8]
- H2C=CH−C≡CH + HCl → H2ClC−CH=C=CH2
- H2ClC−CH=C=CH2 → H2C=CH−CCl=CH2
References
- ^ "New Environment Inc. - NFPA Chemicals".
- ^ Ritzert and Berthol, Chem Ing Tech 45(3), 131-136, Feb 1973, reproduced in Viduari, J Chem Eng Data 20(3), 328-333, 1975.
- ^ Carver, Chemical Process Hazards V, Paper F
- ^ Willstätter, Richard; Wirth, Theodor (1913). "Über Vinyl-acetylen". Berichte der Deutschen Chemischen Gesellschaft. 46: 535–538. doi:10.1002/cber.19130460172.
- ^ G. F. Hennion, Charles C. Price, Thomas F. McKeon, Jr. (1958). "Monovinylacetylene". Organic Syntheses. 38: 70. doi:10.15227/orgsyn.038.0070.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Trotuş, Ioan-Teodor; Zimmermann, Tobias; Schüth, Ferdi (2014). "Catalytic Reactions of Acetylene: A Feedstock for the Chemical Industry Revisited". Chemical Reviews. 114 (3): 1761–1782. doi:10.1021/cr400357r. PMID 24228942.
- ^ Wallace H. Carothers, Ira Williams, Arnold M. Collins, and James E. Kirby (1937). "Acetylene Polymers and their Derivatives. II. A New Synthetic Rubber: Chloroprene and its Polymers". J. Am. Chem. Soc. 53 (11): 4203–4225. doi:10.1021/ja01362a042.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Manfred Rossberg, Wilhelm Lendle, Gerhard Pfleiderer, Adolf Tögel, Eberhard-Ludwig Dreher, Ernst Langer, Heinz Rassaerts, Peter Kleinschmidt, Heinz Strack, Richard Cook, Uwe Beck, Karl-August Lipper, Theodore R. Torkelson, Eckhard Löser, Klaus K. Beutel, "Chlorinated Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry, 2006 John Wiley-VCH: Weinheim.doi:10.1002/14356007.a06_233.pub2