Which is more stable: carbocation or carbanion?

[ashishsinghal]

Is carbocation more stable than carbanion. Why or why not? I feel carbanion should be more stable because the octet of carbon is complete. Is it correct?

 

[Nemus]

That is an interesting question but it is difficult to answer precisely because I can't think of any conditions that would allow for both to exist. I would also vote for carbanions because that stay intact in solution after you generate them. Carbocations tend to rearrange and give mixtures very quickly.

 

[Silex7]

Yes carbocation is more stable. let's take for example the ter-butyl carbocation (Ch3)3-C+ this charged ion is highly stabilized due to the presence of the three donor methly groups that donate electrons, and hence largely stabilize the positive charge.
On the other hand the tert-butyl carbanion (CH3)3-C- would be less stabilized and more reactive than its positive catine since The negatively charged carbon atom in carbanion is sp3 hybridized. Therefore, it has a tetrahedral structure. Three of the four sp3 hybridized orbitals form 3s-bonds with hydrogen or carbon atom of the alkyl group. The fourth sp3 hybrid orbital contains the lone pair of electrons.This would cause to bring the reactivity to this ion and makes it act as a free radicals (check for the reactivity of free radicals).