2-butyne
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | 2-butyne | |||||||||||||||
other names |
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Molecular formula | C 4 H 6 | |||||||||||||||
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properties | ||||||||||||||||
Molar mass | 54.09 g mol −1 | |||||||||||||||
Physical state |
liquid |
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density |
0.69 g cm −3 (20 ° C) |
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Melting point |
−32 ° C |
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boiling point |
27 ° C |
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Vapor pressure |
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solubility |
practically insoluble in water (approx. 3.4 g l −1 ) |
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Refractive index |
1.3921 (20 ° C) |
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safety instructions | ||||||||||||||||
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Thermodynamic properties | ||||||||||||||||
ΔH f 0 |
119.1 kJ / mol |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
2-Butyne (according to IUPAC nomenclature: But-2-yne , rarely also called dimethylacetylene ) is an organic-chemical compound from the group of unsaturated , aliphatic hydrocarbons , more precisely the alkynes . With 5-decyne ( dibutylethyne ), 4-octyne ( dipropylethyne ) and 3-hexyne ( diethylethyne ), it is one of the symmetrical alkynes.
presentation
2-Butyne is obtained from the reaction of propyne with iodomethane (methyl iodide) .
properties
2-Butyne is a colorless, volatile, easily inflammable liquid at room temperature. Due to the triple bond , 2-butyne is a reactive compound; so she goes z. B. with halogen addition reactions . In 2-butyne, the triple bond is between carbon atoms 2 and 3, i.e. inside the molecule. This is why 2-butyne is called an internal alkyne. The vapor pressure function results from log (P) = 21.6295 - (2047.473 / T) - 4.8153 · log (T).
safety instructions
2-butyne is an extremely flammable and irritating substance. It can enter into violent polymerization and addition reactions .
Individual evidence
- ↑ a b c d e f g h i j Entry on 2-butyne in the GESTIS substance database of the IFA , accessed on April 19, 2018(JavaScript required) .
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-84.
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-25.
- ↑ a b G.B. Hazy; HM Davis: Physical Constants of Dimethylacetylene . In: JACS 57 (1935), pp. 339-340, doi : 10.1021 / ja01305a031 .