- They are generated by the breaking of the covalent bond of substrate.
- Are highly reactive.
- Are short-lived species.
5 important types
- Carbocation : carbon atom cantaining six electrons and carries positive charge.
- Carbanion : carbon atom carries the eight electrons and carries negative charge.
- Free radical : carbon atom have six electrons and have at least one unpair electron.
- Carbene : Neutral bivalent carbon atom having six electrons.
- Nitrene : Triplet carbene is more stable than singlet.