Diacetylene

Structural formula
General
Surname	Diacetylene
other names	Butadiyne 1,3-butadiyne
Molecular formula	C 4 H 2
Brief description	colorless gas
External identifiers / databases
CAS number 460-12-8 EC number 207-303-9 ECHA InfoCard 100.006.641 PubChem 9997 Wikidata Q422802
properties
Molar mass	50.05 g mol −1
Physical state	gaseous
Melting point	−36 ° C
boiling point	10.3 ° C
solubility	soluble in water (9.45 g l −1 at 25 ° C)
Refractive index	1.4189 (5 ° C)
safety instructions
GHS hazard labeling no classification available
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

Diacetylene ( butadiyne ) is a chemical compound from the group of unsaturated hydrocarbons and the simplest member of the group of diynes . It has a single and two triple bonds .

Occurrence

Diacetylene could be detected on the moon and in the atmosphere of Saturn's moon Titan .

Extraction and presentation

Diacetylene can be produced as a dimerization product by the oxidative coupling of ethyne . This type of reaction is also known as the Glaser coupling .

${\displaystyle \mathrm {2\ C_{2}H_{2}{\xrightarrow {CuCl,NH_{4}Cl,O_{2}}}C_{4}H_{2}+H_{2}} }$

properties

Diacetylene is extremely flammable and burns in air with a strongly sooty flame to form CO ₂ and H ₂ O (cf. acetylene ). In addition, diacetylene is very reactive due to the triple bonds, e.g. B. Like acetylene (ethyne), it can break down into the elements C and H ₂ in an exothermic reaction . With heavy metal ions such as silver or mercury compounds, explosive salts are formed, similar to other alkynes. Electrophilic additions , polymerizations and Diels-Alder reactions of diacetylene are also known.

use

Diacetylene can be used to make polydiacetylene by polymerization. It is also used as an intermediate for the production of derived compounds (e.g. diphenyldiacetylene liquid crystals).

See also

• 1,3-butadiene
• 1,3-cyclobutadiene
• Butenine

Individual evidence

1. ↑ ^{a b} Scott: MSDS ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
2. ↑ ^{a b} Entry on diacetylene in the ChemIDplus database of the United States National Library of Medicine (NLM) .
3. ↑ 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. 3-72.
4. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
5. ↑ NASA: Article about water finds on the moon ( memento of the original from March 22, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 
6. ↑ DLR: Website about Saturn and its moons ( Memento of the original from October 27, 2004 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
7. ↑ HTW-Aalen: Glaser coupling
8. ↑ L. Roth, U. Weller-Schäferbarthold: Hazardous chemical reactions - Potentially dangerous chemical reactions to over 1750 substances , entry for diacetylene, CD-ROM edition 4/2019, ecomed Sicherheit Landsberg / Lech, ISBN 978-3-609-48040 -4 .