Alkynes
Alkynes are hydrocarbons with at least one triple bond between carbons. The geometry around the triple bond is linear (180°), unlike the double bond (120°) and single bond (109.5°) — this significantly changes the molecule's shape near that point.
General formula
CnH2n-2 (one triple bond)
Naming rule
Name = numerical prefix + infix -yn- + suffix -e, with the triple bond's locant (e.g., but-1-yne). Same lowest-locant numbering rule as alkenes.
Examples
| Name | Formula |
|---|---|
| Ethyne (acetylene) | C₂H₂ |
| Propyne | C₃H₄ |
| But-1-yne | C₄H₆ |
| But-2-yne | C₄H₆ |
| Penta-1,4-diyne | C₅H₄, 2 triple bonds |