Names | |
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Preferred IUPAC name
But-1-en-3-yne
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Other names
Butenyne
3-Butene-1-yne |
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Identifiers | |
3D model (JSmol)
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ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.010.650 |
PubChem CID
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Properties | |
C4H4 | |
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 | |
Main hazards | flammable |
NFPA 704 | |
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).
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what is ?) | (|
Infobox references | |
Vinylacetylene is the organic compound with the formula C4H4. The colourless gas was once used in the polymer industry. It is composed of both alkyne and alkene groups.
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. An example of such an explosion occurred at a Union Carbide plant in Texas City in 1969.
Vinylacetylene was first synthesized by Hofmann elimination of the related quaternary ammonium salt:
It is usually synthesized by dehydrohalogenation of 1,3-dichloro-2-butene. It also arises via the dimerization of acetylene or dehydrogenation of 1,3-butadiene.
At one time, chloroprene (2-chloro-1,3-butadiene), an industrially important monomer, was produced via the intermediacy of vinyl acetylene. 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: