Question

Which is more stable resonance or hyperconjugation?

Answer 1

Resonance:

1. In valence bond theory, resonance, also known as mesomerism, is a means of characterizing bonding in particular molecules or polyatomic ions by combining many contributing structures into a resonance hybrid.

Hyperconjugation:

1. Because both approaches allow a molecule to stabilize by delocalizing electrons, hyperconjugation is an extension of resonance.
2. However, hyperconjugation requires delocalization of sigma bond electrons as well as pi bond electrons, whereas resonance only induces delocalization of sigma bond electrons.

Stability:

1. Resonance allows for delocalization, which lowers a molecule's total energy as the electrons inhabit a larger space, making molecules that experience resonance more stable than those that do not.
2. These are referred to as stabilized resonance compounds.

Hence, resonance is more stable than hyperconjugation.