Hi, I have some genuine difficulties regarding Hyperconjugation,plaese help.
0] Does the displacement of bond pair from c-h to FORM C=C really occurs or it is a way to explain the observed properties of the molecules
[ because hyperconj. is resonance in which of sigma electrons R displaced .]
1] Why is it that more the hyperconjugation effect more is the INDUCTIVE EFFECT of an alkyl group attached to an unsaturated carbon chain?
My logic – In the hyperconjugatives forms the C-H bond pair is transferred to C-C to form C=C bond , presence of such hyperconjugative forms leads to the shift of electrons away from the alkyl group as net effect in the original form . This is nothing but inductive effect.
2] What are the hyperconjugative forms of a carbon anions e.g. tert.-butyl carbonium ion?
When the bond pair is displaced in carbon cations from c-h to c=c the ion gets discharged , but when it would happen in the carbon anion the negatively charged C we repel the b.p. and this will also provide a negative centre of for electrophiles and thus , decrease the stability of the molecule , so , I have doubt about the formation of the double bond [c=c] , the factor that increases stability of the molecule is the distribution of the positive charge over the H atoms of the alkyl group , is it so powerful that solely it makes the molecule more stable as a net effect?
3] Why is the order of stability of carbon anions ions same as the cabocations i.e. tert.> sec.>primary>methyl ?
More the inductive effect more unstable will be the ion as repulsion between the C- [minus] & bond pair increases . So the order of stability would be primary>sec.>tert. i.e. revesrse of that of carbon cations. But if the distribution of positive charge is a powerful stabilizer then the order would be the same as that of carbon.
Please find a file attached with an one more difficulty.hrushikesh