The interaction between $$\pi$$ bond and lone pair of electrons present on an adjacent atom is responsible for

Question: The interaction between a $$\pi$$ bond and a lone pair of electrons present on an adjacent atom is responsible for which effect?

Review the electronic effects in organic chemistry.

Hyperconjugation (Option 1): This involves the interaction between $$\sigma$$ bond electrons (particularly C-H bonds) and an adjacent empty or partially filled p-orbital or $$\pi$$ system. It does not involve lone pairs directly.

Inductive effect (Option 2): This is the transmission of charge through a chain of atoms via $$\sigma$$ bonds. It involves $$\sigma$$ bonds only, not $$\pi$$ bonds or lone pairs interacting with each other.

Electromeric effect (Option 3): This is a temporary effect that occurs when a reagent approaches a $$\pi$$ bond, causing complete transfer of the $$\pi$$ electron pair. It does not specifically involve lone pairs on adjacent atoms.

Resonance effect (Option 4): Resonance (also called the mesomeric effect) involves the delocalisation of electrons through $$\pi$$ bonds and lone pairs on adjacent atoms. When a lone pair on an atom adjacent to a $$\pi$$ bond participates in conjugation, it is the resonance effect. For example, in aniline ($$C_6H_5NH_2$$), the lone pair on N interacts with the $$\pi$$ system of the benzene ring.

The correct answer is Option 4: Resonance effect.