An acetylide ion is a negatively charged ion derived from a terminal alkyne (a hydrocarbon with a carbon–carbon triple bond).
Chemical Representation:
- General form: RC≡C⁻
- Example: From acetylene (ethyne, HC≡CH), removing a hydrogen ion (H⁺) forms:
HC≡C⁻ (acetylide ion)
Explanation:
- Terminal alkynes have a hydrogen atom attached to a carbon with a triple bond
- This hydrogen is slightly acidic and can be removed by a strong base
- The remaining species is the acetylide ion
Formation Reaction:
HC≡CH + NaNH₂ → HC≡C⁻ Na⁺ + NH₃
Properties:
- Strong nucleophile
- Strong base
- Highly reactive
Uses:
- Used in organic synthesis to form new carbon–carbon bonds
- Important in preparing longer carbon chains
Conclusion:
An acetylide ion is a reactive, negatively charged species formed from terminal alkynes, widely used in organic chemistry reactions.