| 2-Butene | |
|---|---|
 |
|
| IUPAC name |
But-2-ene
|
| Other names | β-Butylene |
| Identifiers | |
| CAS number | 107-01-7  |
| EC-number | 203-452-9 |
| RTECS number | EM2932000 |
| SMILES |
C(=CC)C
|
| InChI |
1/C4H8/c1-3-4-2/h3-4H,1-2H3
|
| InChI key | IAQRGUVFOMOMEM-UHFFFAOYAW |
| ChemSpider ID | 11719 |
| Properties | |
| Molecular formula | C4H8 |
| Molar mass | 56.106 g/mol |
| Hazards[1] | |
| EU Index | 601-012-00-4 |
| EU classification | Extremely flammable (F+) |
| R-phrases | R12 |
| S-phrases | (S2) S9 S16 S33 |
| NFPA 704 |
 4
1
0
|
| Flash point | flammable gas |
| Autoignition temperature |
324 ºC (615 ºF) |
| Related compounds | |
| Related butenes | 1-Butene cis-2-Butene trans-2-Butene Isobutene |
| Related compounds | Butane Butyne |
| (what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
2-Butene is an acyclic alkene with four carbon atoms. It is the simplest alkene to shown cis/trans-isomerism (also known as (E/Z)-isomerism); that is, it exists as two geometrical isomers cis-2-butene ((Z)-2-butene) and trans-2-butene ((E)-2-butene).
It is a petrochemical, produced by the catalytic cracking of crude oil. Its main uses are in the production of gasoline (petrol) and butadiene,[2] although some 2-butene is also used to produce the solvent butanone via hydration to 2-butanol followed by oxidation.
The two isomers are extremely difficult to separate by distillation because of the proximity of their boiling points (4 °C for cis and 1 °C for trans[3]). However, separation is unnecessary in industrial settings, as both isomers behave similarly in the desired reactions. A typical industrial 2-butene mixture is 70% (Z)-2-butene (cis-isomer) and 30% (E)-2-butene (trans-isomer). Butane and 1-butene are common impurities, present at 1% or more in industrial mixtures, which also contain smaller amounts of isobutene, butadiene and butyne.[2]
References
- ^ cis-2-Butene, International Chemical Safety Card 0397, Geneva: International Labour Organization, March 1996, http://www.inchem.org/documents/icsc/icsc/eics0397.htm. trans-2-Butene, International Chemical Safety Card 0398, Geneva: International Labour Organization, March 1996, http://www.inchem.org/documents/icsc/icsc/eics0398.htm.
- ^ a b 2-Butene, SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, February 1995, http://www.inchem.org/documents/sids/sids/107017.pdf.
- ^ Chemical Safety Information from Intergovernmental Organizations
External links
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