|Jmol-3D images||Image 1|
|Molar mass||50.06 g mol−1|
|Melting point||−10 °C (14 °F; 263 K)|
|Boiling point||10 °C (50 °F; 283 K)|
|Main hazards||Highly flammable|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Diacetylene (also known as butadiyne), with the formula C4H2, is a highly unsaturated hydrocarbon that contains three single bonds and two triple bonds. It is the first in the series of polyynes. The trivial name "diacetylene" refers to the two C-C triple bonds and the possible formation from acetylene (see below). It does not mean that diacetylene is the formal dimer of acetylene, what is rather true for Butenyne or Cyclobutadiene.
Diacetylene has been identified in the atmosphere of Titan and in the protoplanetary nebula CRL 618 by its characteristic vibrational modes. The molecule is most likely to have formed in Titan's atmosphere 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 found on the Moon.
This compound may be made by the dehydrohalogenation of 1,4-dichloro-2-butyne by potassium hydroxide at low temperature:
- ClCH2C≡CCH2Cl → HC≡C-C≡CH
- 2 TMS-C≡CH → TMS-C≡C-C≡C-TMS
- "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", Org. Synth.; Coll. Vol. 8: 63
- Maretina, Irina A; Trofimov, Boris A (2000). "Diacetylene: a candidate for industrially important reactions". Russian Chemical Reviews 69 (7): 591. doi:10.1070/RC2000v069n07ABEH000564.