alkyne

Alkenes (also called olefins) and alkynes (also called acetylenes) belong to the class of unsaturated aliphatic hydrocarbons. Alkenes are hydrocarbons that contain a carbon-carbon double bond, whereas alkynes have a carbon-carbon triple bond. Alkenes are characterized by the general molecular formula C_nH_2n

Molecules that contain a triple bond between two carbon atoms are known as alkynes. The triple bond is made up of one σ bond and two π bonds. As in alkenes, the π bonds constitute regions of increased electron density lying parallel to the…

…a carbon-carbon double bond, and alkynes contain a carbon-carbon triple bond. Aromatic hydrocarbons are those that are significantly more stable than their Lewis structures would suggest; i.e., they possess “special stability.” They are classified as either arenes, which contain a benzene ring as a structural unit, or nonbenzenoid aromatic hydrocarbons,…

…of Fischer carbene complexes with alkynes has considerable utility in organic synthesis. For example, naphthyl compounds (i.e., those derived from the fused ring system C₁₀H₈) can be synthesized by the reaction of methoxy phenyl Fischer carbenes with an alkyne.

An alkene ligand contains a π bond between carbon atoms, C=C, which can serve as an electron pair donor in a metal complex, as in the case of Zeise’s salt (see above Historical developments). This complex may be prepared by bubbling ethylene, C₂H₄,…

…a carbon-to-carbon double bond, and alkynes, which have a carbon-to-carbon triple bond—and aldehydes and ketones, which have a carbon-to-oxygen double bond. An addition reaction may be visualized as a process by which the double or triple bonds are fully or partially broken in order to accommodate additional atoms or groups…

When a hydrogen halide adds to the carbon-carbon triple bond of an alkyne, addition of the first molecule is faster than the second, and a vinylic halide can be isolated.