Question

The type of delocalization involving sigma bond orbitals with $\pi$ bond or vacant orbital is called:

• A. inductive effect
• B. hyperconjugation
• C. electromeric effect
• D. mesomeric effect

Answer 1

Answer: (B)

hyperconjugation

Hyperconjugation is the interaction of the electrons in a sigma bond (usually $C–HorC–C$) with an adjacent empty (or partially filled) non-bonding p-orbital, antibonding $\sigma or\pi$ orbital, or filled $\pi$ orbital, to give an extended molecular orbital that increases the stability of the system.

This type of delocalization involving $\sigma$ bond orbitals with $\pi$ bond or vacant orbital is called hyperconjugation.