Diacetylene (also known as butadiyne) is the organic compound with the formula C4H2. It is the simplest compound containing two triple bonds. It is first in the series of polyynes, which are of theoretical but not of practical interest.
|Preferred IUPAC name
3D model (JSmol)
|Molar mass||50.06 g·mol−1|
|Boiling point||10 °C (50 °F; 283 K)|
|Main hazards||Highly flammable|
|Safety data sheet||External MSDS|
|R-phrases (outdated)||R11 R19|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Diacetylene has been identified in the atmosphere of Titan and in the protoplanetary nebula CRL 618 by its characteristic vibrational spectrum. It is proposed to arise by a reaction between acetylene and the ethynyl radical (C2H), which is produced when acetylene undergoes photolysis. This radical can in turn attack the triple bond in acetylene and react efficiently even at low temperatures. Diacetylene has also been detected on the Moon.
This compound may be made by the dehydrohalogenation of 1,4-dichloro-2-butyne by potassium hydroxide (in alcoholic medium) at ~70°C:
- ClCH2C≡CCH2Cl + 2 KOH → HC≡C−C≡CH + 2 KCl + 2 H2O
- 2 Me3Si−C≡CH → Me3Si−C≡C−C≡C−SiMe3
- "The Multiplying Mystery of Moonwater", March 18, 2010. Retrieved on 2010-03-18.
- Verkruijsse, H. D.; Brandsma, L. (1991). "A Detailed Procedure for the Preparation of Butadiyne". Synthetic Communications. 21 (5): 657. doi:10.1080/00397919108020833.
- Graham E. Jones, David A. Kendrick, and Andrew B. Holmes (1993). "1,4-Bis(trimethylsilyl)buta-1,3-diyne". Organic Syntheses. doi:10.15227/orgsyn.065.0052. ; Collective Volume, 8, p. 63