Question

Explain hyperconjugation in propene.

Answer 1

Hyperconjugation: It involves delocalisation of sigma electrons of C-H bond of an alkyl group directly attached to an atom of unsaturated system or an atom with an unshared p orbital. The hyperconjugating structures of propene are represented as: Total number of hyperconjugating structures in propene = 3.

Answer 2

Explanation:

Hyper conjugation is the interaction of electrons in a sigma bond, generally the C – H or C – C, with an adjoining empty or partly filled non-bonding p-orbital, π orbital or anti-bonding π, to offer an expanded molecular orbital that improves system stability.

Hyper conjugation occurs in the propene molecule owing to partial overlap of the orbital sp3-sigma bond and the vacant p-orbital neighboring carbon atom. Here one of the methyl group's carbon-hydrogen bonds can lie in the orbital pi-bond plane, thus partially overlapping with the orbital π  bond.