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Names | |||
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Preferred IUPAC name But-2-ene | |||
Other names β-Butylene | |||
Identifiers | |||
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3D model (JSmol) |
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1718755 1361341 | |||
ChEBI |
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ChemSpider | |||
ECHA InfoCard | 100.003.140 ![]() | ||
EC Number |
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25196 1140 1141 | |||
PubChem CID | |||
RTECS number |
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UNII |
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CompTox Dashboard (EPA) | |||
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Properties | |||
C4H8 | |||
Molar mass | 56.106 g/mol | ||
Density | 0.641 g/mL (cis, at 3.7 °C) [1] 0.626 g/mL (trans, at 0.9 °C) [2] | ||
Melting point | −138.9 °C (−218.0 °F; 134.2 K)(cis) [1] -105.5 °C (trans) [2] | ||
Boiling point | 0.8 to 3.7 °C (33.4 to 38.7 °F; 273.9 to 276.8 K)(Z = 3.7 °C) [1] (E = 0.8 °C) [2] | ||
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Hazards [3] | |||
GHS classification and labelling: | |||
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Danger | |||
H220 | |||
P210, P377, P381, P403 | |||
NFPA 704 (fire diamond) | |||
Flash point | −72 °C (−98 °F; 201 K) [1] [2] | ||
325 °C (617 °F; 598 K) [1] [2] | |||
Related compounds | |||
Related butenes | 1-Butene cis-2-Butene trans-2-Butene Isobutene | ||
Related compounds | Butane Butyne | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
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Infobox references | |||
2-Butene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting cis/trans-isomerism (also known as (E/Z)-isomerism); that is, it exists as two geometric 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 or the dimerization of ethylene. Its main uses are in the production of gasoline (petrol) and butadiene, [4] 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 [5] ). However, separation is unnecessary in most industrial settings, as both isomers behave similarly in most of 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. [4]
In chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond.
1,3-Butadiene is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two vinyl groups. It is the simplest conjugated diene.
1-Hexanol (IUPAC name hexan-1-ol) is an organic alcohol with a six-carbon chain and a condensed structural formula of CH3(CH2)5OH. This colorless liquid is slightly soluble in water, but miscible with diethyl ether and ethanol. Two additional straight chain isomers of 1-hexanol, 2-hexanol and 3-hexanol, exist, both of which differing by the location of the hydroxyl group. Many isomeric alcohols have the formula C6H13OH. It is used in the perfume industry.
Pentane is an organic compound with the formula C5H12—that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer; the other two are called isopentane (methylbutane) and neopentane (dimethylpropane). Cyclopentane is not an isomer of pentane because it has only 10 hydrogen atoms where pentane has 12.
Fumaric acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. The salts and esters are known as fumarates. Fumarate can also refer to the C
4H
2O2−
4 ion (in solution). Fumaric acid is the trans isomer of butenedioic acid, while maleic acid is the cis isomer.
Butene, also known as butylene, is an alkene with the formula C4H8. The word butene may refer to any of the individual compounds. They are colourless gases that are present in crude oil as a minor constituent in quantities that are too small for viable extraction. Butene is therefore obtained by catalytic cracking of long-chain hydrocarbons left during refining of crude oil. Cracking produces a mixture of products, and the butene is extracted from this by fractional distillation.
Isobutylene (or 2-methylpropene) is a hydrocarbon with the formula (CH3)2C=CH2. It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value.
2-Butanol, or sec-butanol, is an organic compound with formula CH3CH(OH)CH2CH3. This secondary alcohol is a flammable, colorless liquid that is soluble in three parts water and completely miscible with organic solvents. It is produced on a large scale, primarily as a precursor to the industrial solvent methyl ethyl ketone. 2-Butanol is chiral and thus can be obtained as either of two stereoisomers designated as (R)-(−)-2-butanol and (S)-(+)-2-butanol. It is normally encountered as a 1:1 mixture of the two stereoisomers — a racemic mixture.
Maleic acid or cis-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO2CCH=CHCO2H. Maleic acid is the cis-isomer of butenedioic acid, whereas fumaric acid is the trans-isomer. It is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride, maleic acid has few applications.
Pentenes are alkenes with the chemical formula C
5H
10. Each contains one double bond within its molecular structure. Six different compounds are in this class, differing from each other by whether the carbon atoms are attached linearly or in a branched structure, and whether the double bond has a cis or trans form.
Adiponitrile is the organic compound with the formula (CH2)4(CN)2. This dinitrile, a viscous, colourless liquid, is an important precursor to the polymer nylon 66. In 2005, about one million tonnes were produced.
1,2-Dichloroethene, commonly called 1,2-dichloroethylene or 1,2-DCE, is an organochloride with the molecular formula C2H2Cl2. It is a highly flammable, colorless liquid with a sharp, harsh odor. It can exist as either of two geometric isomers, cis-1,2-dichloroethene or trans-1,2-dichloroethene, but is often used as a mixture of the two. They have modest solubility in water. These compounds have few industrial applications, although they are fundamental given their simple stoichiometries.
Nonene is an alkene with the molecular formula C9H18. Many structural isomers are possible, depending on the location of the C=C double bond and the branching of the other parts of the molecule. Industrially, the most important nonenes are trimers of propene: Tripropylene. This mixture of branched nonenes is used in the alkylation of phenol to produce nonylphenol, a precursor to detergents, which are also controversial pollutants.
Butan-1-ol, also known as n-butanol is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of butan-1-ol are isobutanol, butan-2-ol and tert-butanol. The unmodified term butanol usually refers to the straight chain isomer.
Terpineol is any of four isomeric monoterpenoids. Terpenoids are terpene that are modified by the addition of a functional group, in this case, an alcohol. Terpineols have been isolated from a variety of sources such as cardamom, cajuput oil, pine oil, and petitgrain oil. Four isomers exist: α-, β-, γ-terpineol, and terpinen-4-ol. β- and γ-terpineol differ only by the location of the double bond. Terpineol is usually a mixture of these isomers with α-terpineol as the major constituent.
An occupational exposure limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials. It is typically set by competent national authorities and enforced by legislation to protect occupational safety and health. It is an important tool in risk assessment and in the management of activities involving handling of dangerous substances. There are many dangerous substances for which there are no formal occupational exposure limits. In these cases, hazard banding or control banding strategies can be used to ensure safe handling.
The Institute for Occupational Safety and Health of the German Social Accident Insurance is a German institute located in Sankt Augustin near Bonn and is a main department of the German Social Accident Insurance. Belonging to the Statutory Accident Insurance means that IFA is a non-profit institution.
Decene is an alkene with the formula C
10H
20. Decene contains a chain of ten carbon atoms with one double bond. There are many isomers of decene depending on the position and geometry of the double bond. Dec-1-ene is the only isomer of industrial importance. As an alpha olefin, it is used as a comonomer in copolymers and is an intermediate in the production of epoxides, amines, oxo alcohols, synthetic lubricants, synthetic fatty acids and alkylated aromatics.
1,2-Butanediol is the organic compound with the formula HOCH2(HO)CHCH2CH3. It is classified as a vic-diol (glycol). It is chiral, although typically it is encountered as the racemic mixture. It is a colorless liquid.
Dinitrobenzenes are chemical compounds composed of a benzene ring and two nitro group (-NO2) substituents. The three possible arrangements of the nitro groups afford three isomers, 1,2-dinitrobenzene, 1,3-dinitrobenzene, and 1,4-dinitrobenzene. Each isomer has the chemical formula C6H4N2O4 and a molar mass of about 168.11 g/mol. 1,3-Dinitrobenzene is the most common isomer and it is used in the manufacture of explosives.