Question

Write a short note on hyperconjugation and give all hyperconjugated structures of propene.

Answer 1

Hyper-conjugation is the interaction of the electrons in a $\sigma$ bond 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.

In case of propene, hyperconjugation arise due to partial overlap of $s{p}^3$ sigma bond orbital and the empty p-orbital of an adjacent $c-atom.$

Here one of the C-atom $C-H$ bonds of $-C{H}_3$ group can lie in the plane of pi-bond orbital, hence partial overlapping.

See the given structure.