Alkyne

An alkyne is a molecule that has a triple bond between two carbon atoms. They have general formula C_nH_2n-2. They are also called acetylenes. The smallest alkyne is acetylene, also called ethyne. Alkynes are hydrophobic: this means they dissolve well in organic solvents but not in water.

Alkynes are more reactive than usual hydrocarbons. For example, they are more reactive than alkenes in many reactions. If the alkyne is at the end of a molecule, it is easy to remove the proton with a strong base. Then, the alkyne can be used in addition reactions. For example, it can be added to a ketone. Alkynes are also easy to reduce to double bonds. They can be made into both trans and cis double bonds. Alkynes are also used a lot in pericyclic reactions.

Structure

Alkynes have a 180 degrees angle between the two carbon atoms. For this reason, they do not like to be in a cyclic compound. Some examples of alkynes are shown below.

Examples of alkynes

List of alkynes

The following is a list of the first 15 alkynes:

1. Ethyne C₂H₂
2. Propyne C₃H₄
3. Butyne C₄H₆
4. Pentyne C₅H₈
5. Hexyne C₆H₁₀
6. Heptyne C₇H₁₂
7. Octyne C₈H₁₄
8. Nonyne C₉H₁₆
9. Decyne C₁₀H₁₈
10. Undecyne C₁₁H₂₀
11. Dodecyne C₁₂H₂₂
12. Tridecyne C₁₃H₂₄
13. Tetradecyne C₁₄H₂₆
14. Pentadecyne C₁₅H₂₈
15. Hexadecyne C₁₆H₃₀