Alkyne One of a group of organic compounds containing a carbon-to-carbon triple-bond linkage (-C≡C-). They are termed acetylenes or alkynes. While exhibiting many of the characteristics of alkenes as regards unsaturation, the acetylenes have many unique properties. Since the bonding in alkyne molecules is linear. R-C≡C-R, cis-trans isomerism is not possible. In the simplest alkyne,