2-Butyne

Source: Wikipedia, the free encyclopedia.
2-Butyne[1][2]
Ball-and-stick model
Names
Preferred IUPAC name
But-2-yne
Other names
Dimethylacetylene
Crotonylene
Identifiers
3D model (
JSmol
)
ChEMBL
ChemSpider
ECHA InfoCard
100.007.239 Edit this at Wikidata
UNII
  • InChI=1S/C4H6/c1-3-4-2/h1-2H3 checkY
    Key: XNMQEEKYCVKGBD-UHFFFAOYSA-N checkY
  • InChI=1/C4H6/c1-3-4-2/h1-2H3
    Key: XNMQEEKYCVKGBD-UHFFFAOYAO
  • C(#CC)C
Properties
C4H6
Molar mass 54.0904 g/mol
Density 0.691 g/mL
Melting point −32 °C (−26 °F; 241 K)
Boiling point 27 °C (81 °F; 300 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

2-Butyne (dimethylacetylene, crotonylene or but-2-yne) is an alkyne with chemical formula CH3C≡CCH3. Produced artificially, it is a colorless, volatile, pungent liquid at standard temperature and pressure.

2-Butyne is of interest to physical chemists because of its very low torsional barrier and the problem of determining that barrier using high-resolution infrared spectroscopy. Analysis of its spectrum[3] leads to a determination that the torsional barrier is only 6 cm−1 (1.2×10−22 J or 72 J mol−1). However, it has not been determined whether the equilibrium structure is eclipsed (D3h) or staggered (D3d). Symmetry analysis using the Molecular Symmetry Group[4][5] G36 shows that one would need to analyse its high resolution rotation-vibration Raman spectrum to determine its equilibrium structure.

2-Butyne (dimethylethyne) forms with

3-hexyne
(diethylethyne) a group of symmetric alkynes.

Synthesis

2-Butyne can be synthesized by the

ethylacetylene in a solution of ethanolic potassium hydroxide.[6]

Applications

2-Butyne, along with

See also

References