Carbanion Stability | Summary and Q&A

TL;DR

Tertiary carbo-cations are more stable than secondary or primary carbo-cations due to the hyperconjugation and inductive effects. Methyl groups can stabilize carbo-cations through electron donation. In contrast, methyl carbon-ions are more stable than tertiary carbon-ions in the carbo-ion case.

Key Insights

• 🙇 Tertiary carbo-cations are the most stable in the group, thanks to the hyperconjugation and inductive effects.
• 👥 Methyl groups stabilize carbo-cations through electron donation, enhancing stability.
• 😑 In contrast, methyl carbon-ions are more stable than tertiary carbon-ions in the case of carbo-ions due to unfavorable electron donation.

Transcript

in this video we're gonna talk about carbon and stability but before we do that let's discuss carbo cation stability now remember a carbo cation is basically a carbon with a positive charge here we have a tertiary carbo cation the reason why its tertiary is because the carbo cation that is the carbon with the positive charge is attached to three ot... Read More

Questions & Answers

Q: Why are tertiary carbo-cations more stable than primary carbo-cations?

Tertiary carbo-cations are more stable due to the hyperconjugation effect and the inductive effect. The presence of three carbon atoms attached to the carbo-cation enhances stability through increased electron delocalization.

Q: How do methyl groups stabilize carbo-cations?

Methyl groups act as electron donating groups, providing electron density to the carbo-cation. This electron donation stabilizes the carbo-cation through the inductive effect.

Q: Why are methyl carbon-ions more stable than tertiary carbon-ions?

In the case of carbo-ions, the presence of a negative charge makes electron donation unfavorable. Since methyl groups are electron donating, they destabilize the carbo-ion. Therefore, tertiary carbon-ions are less stable compared to methyl carbon-ions.

Q: Why are secondary allylic carbonates more stable?

Secondary allylic carbonates are more stable due to resonance. The negative charge can be delocalized over two carbon atoms, resulting in a more stable situation compared to a localized negative charge on one carbon atom.

Summary & Key Takeaways

• Tertiary carbo-cations are the most stable, followed by secondary and primary carbo-cations. Methyl groups stabilize carbo-cations through electron donation.

• However, in the case of carbo-ions, methyl carbon-ions are more stable than tertiary carbon-ions.

• Secondary allylic carbonates are more stable than regular secondary carbonates due to resonance.