Questions tagged [hyperconjugation]

Hyperconjugation involves the donation of electrons from a filled orbital (commonly the bonding C-H sigma molecular orbital) into an adjacent/partially occupied p-orbital (for instance an adjacent carbocation) leading to stabilisation. The tag should be applied to questions where hyperconjugation is involved, even if the question does not explicitly refer to it.

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On the directing nature of these groups in electrophilic aromatic substitution

These three groups are listed in our workbook. I don't know the answer and our teacher isn't sure either: (each has a free valency through which it is attached to a benzene ring): ...
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0answers
886 views

On baker nathan hyperconjugation

Recently I have been reading about the history of the Baker Nathan reaction. In addition to the large rate increase for Me vs H, all the other alkyl groups showed decreases with respect to Me ...
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0answers
224 views

Why don't we have hyperconjugation with C-C bonds?

C-C bonds are weaker than C-H bonds.So why is hyperconjugation with C-C bonds not possible?
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266 views

Negative hyperconjugation stabilizes tricyclopentane derivate

As far as I know, negative hyperconjugation means, that we have electrons that are transferred from a p- or $\pi$- to a $\sigma^*$-orbital. In the lecture, we analyzed a TMS-substituted ...
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177 views

Confusion about gauche effect

This recent question about the gauche effect led me to read this rather older answer. The problem is that I notice I am still confused. To take the case of 1,2 difluoroethane, I drew these orbitals: ...
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34 views

Number of hyperconjugative structures in aromatic systems

I know that to find the number of hyperconjugative structures in aliphatic systems we use the formula $a + 1$ (where $a$ is the number of α-hydrogens in that compound) However, my teacher answered ...
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1answer
65 views

Stability of alkene

Sorry for this silly doubt but why is CR2=CH2 alkene more stable than CHR=CHR alkene? Both have same number of alpha hydrogens. I thought that the latter is more stable as in its trans isomer, the R ...
-1
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1answer
514 views

How does hyperconjugation explain the stability of alkenes?

The more the number of alpha hydrogens, the higher is the stability of alkenes, because the more the number of hyperconjugative structures. Why is this so? Has it got something to do with the ...
-1
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1answer
123 views

Stability order of methy benzyl cations?

I know that meta position shown no resonance effect and hyperconjugation effect . So According to the order given I guess Hyperconjugating effect is taken into account as -CH3 has no Resonance effects....
-1
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1answer
323 views

Can hyperconjugation take place between lone pairs of an atom attached to an sp2 carbon?

When $\ce{HBr}$ is added to 2-chloro-2-butene, the proton preferentially bonds to the $sp^2$ carbon that's not bonded to chlorine. Does this mean that hyperconjugation takes place between the lone ...