Hyperconjugation is a general stabilising interaction. It involves delocalisation of σ electrons of C—H bond of an alkyl group directly attached to an atom of unsaturated system or to an atom with an unshared p orbital. The σ electrons of C—H bond of the alkyl group enter into partial conjugation with the attached unsaturated system or with the unshared p orbital. Hyperconjugation is a permanent effect.
To understand hyperconjugation effect, let us take an example of (ethyl cation) in which the positively charged carbon atom has an empty p orbital. One of the C-H bonds
of the methyl group can align in the plane of this empty p orbital and the electrons constituting the C-H bond in plane with this p orbital can then be delocalised into the
empty p orbital.
This type of overlap stabilises the carbocation because electron density from the adjacent σ bond helps in dispersing the
positive charge.
Hyperconjugation is also possible in alkenes and alkylarenes. Delocalisation of electrons by hyperconjugation in the case of alkene as shown in the video.
There are various ways of looking at the hyperconjugative effect. One of the way is to regard C—H bond as possessing partial ionic character due to resonance.
To understand hyperconjugation effect, let us take an example of (ethyl cation) in which the positively charged carbon atom has an empty p orbital. One of the C-H bonds
of the methyl group can align in the plane of this empty p orbital and the electrons constituting the C-H bond in plane with this p orbital can then be delocalised into the
empty p orbital.
This type of overlap stabilises the carbocation because electron density from the adjacent σ bond helps in dispersing the
positive charge.
Hyperconjugation is also possible in alkenes and alkylarenes. Delocalisation of electrons by hyperconjugation in the case of alkene as shown in the video.
There are various ways of looking at the hyperconjugative effect. One of the way is to regard C—H bond as possessing partial ionic character due to resonance.
https://t.co/40Ice7AwAr pic.twitter.com/kdz1VkQBlG
— Abraham Malik (@brhmmlk93_malik) February 11, 2015
http://advancedmathematicalresearch.blogspot.in/
Name Your Link
No comments:
Post a Comment