What is the Difference Between Isovalent and Sacrificial Hyperconjugation?
🆚 Go to Comparative Table 🆚The key difference between isovalent and sacrificial hyperconjugation lies in the charge distribution and the types of structures involved. Hyperconjugation refers to the interaction of σ-bonds with a pi network. Here are the main differences between the two types of hyperconjugation:
- Isovalent Hyperconjugation:
- Occurs in free radicals and carbocations.
- The canonical form displays no charge separation.
- The main form has a charge separation.
- The contributing structure has the same number of two-electron bonds as the usual Lewis formula.
- Sacrificial Hyperconjugation:
- The canonical form involves no bond resonance.
- The main form has no charge distribution.
- This type of hyperconjugation is less common than isovalent hyperconjugation.
In summary, isovalent hyperconjugation involves free radicals and carbocations with no charge separation in the canonical form, while sacrificial hyperconjugation involves a lack of bond resonance in the canonical form and no charge distribution in the main form.
Comparative Table: Isovalent vs Sacrificial Hyperconjugation
The difference between isovalent and sacrificial hyperconjugation can be summarized in the following table:
Feature | Isovalent Hyperconjugation | Sacrificial Hyperconjugation |
---|---|---|
Occurrence | Occurs in free radicals and carbocations where the canonical form displays no charge separation | Occurs in systems where the canonical form involves no bond resonance |
Contributing Structure | The contributing structure has the same number of two-electron bonds as the conjugated system | The contributing structure has one less two-electron bond than the conjugated system |
Bond Order | The bond order in the alpha carbon atom is approximately 1.5 | The bond order in the alpha carbon atom is approximately 1 |
In isovalent hyperconjugation, the interaction of σ-bonds with a pi network takes place in free radicals and carbocations, with the main form having no charge separation. On the other hand, sacrificial hyperconjugation occurs when the canonical form of a system involves no bond resonance, and one of the hydrogen atoms is missing from the structure, making the bond order of the alpha carbon atom approximately 1.
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- Hyperconjugation vs Resonance
- Hyperconjugation vs Inductive Effect
- Conjugated vs Isolated Double Bond
- Conjugation vs Resonance
- Resonance vs π Conjugation
- Isoelectronic vs Isosteres
- Isomers vs Resonance
- Oxazole vs Isoxazole
- Hypervalent vs Hypovalent Compounds
- Isostructural vs Isomorphous
- Isomerization vs Hydroisomerization
- Thiocyanate vs Isothiocyanate
- Covalent Bond vs Dative Bond
- Electrovalent vs Covalent Bond
- Homolytic vs Heterolytic Bond Dissociation Energy
- Congener vs Isomer
- Isotopes vs Isomers
- Hybridized vs Unhybridized Orbitals