Antibonding Orbital
| Formula / Notation | σ* and π* notation; energy higher than bonding MO |
|---|---|
| Also Known As | Antibonding MO, σ* orbital, π* orbital, destabilising orbital |
What is Antibonding Orbital?
An antibonding orbital (denoted with an asterisk, e.g., σ* or π*) is a molecular orbital whose electron density weakens the bond between atoms. Electrons in antibonding orbitals destabilise a molecule; if enough antibonding orbitals are occupied, the molecule may not be stable. The presence of antibonding electrons reduces bond order.
Formula & Notation
Other Names / Synonyms: Antibonding MO, σ* orbital, π* orbital, destabilising orbital
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
An antibonding orbital (denoted with an asterisk, e.g., σ* or π*) is a molecular orbital whose electron density weakens the bond between atoms. Electrons in antibonding orbitals destabilise a molecule; if enough antibonding orbitals are occupied, the molecule may not be stable. The presence of antibonding electrons reduces bond order.
Antibonding orbital concepts explain why molecules like He₂ do not exist (bond order = 0), why O₂ is paramagnetic, and underpin ultraviolet-visible spectroscopy (π→π* and n→π* electronic transitions). They are central to molecular orbital (MO) theory and photochemistry.
No direct safety concern for the concept itself. Knowledge of antibonding orbitals aids understanding of photochemical reactions where UV light promotes electrons into antibonding orbitals, potentially causing bond cleavage and generation of reactive intermediates.
The formula or notation for Antibonding Orbital is: σ* and π* notation; energy higher than bonding MO