Lecture on Molecular Orbital Theory and 2p Orbitals

Introduction to 2p Orbitals

• Different types of 2p orbitals are considered along the bond direction.
• Valence bond theory allows for bonding interactions.
• Focus on understanding these interactions in Molecular Orbital Theory.

Characteristics of 2p Orbitals

• 2p orbitals are degenerate (having the same energy level).
• Each 2p orbital has a positive and a negative wave character.

Bonding Interactions in 2p Orbitals

• Constructive Interference:
  • Occurs when both sides of the p orbital have the same wave character.
  • Results in high electron density along the bond.
  • Forms a sigma (σ) bond from the 2p orbital.
• Destructive Interference: Anti-Bonding:
  • Occurs when opposite wave characters are combined, leading to cancellation.
  • Results in an anti-bonding orbital, higher in energy.
  • Denoted as sigma star (σ*) and associated with 2p.

Comparison with 2s Orbitals

• Both 2s and 2p can form sigma bonds with electron density in the bond center.
• Anti-bonding orbitals show no electron density in the bond center.
• Depiction of sigma 2s and sigma 2p with correlation lines.

Visualization

• Hand sketches can illustrate bonding and anti-bonding interactions.
• Anti-bonding 2s and 2p orbitals show higher energy levels.
• Correlation lines can be drawn to show origins from 2p orbitals.

Summary

• Understanding the nature of wave characters helps in predicting bonding.
• Molecular Orbital Theory provides a framework to visualize orbital interactions, particularly for 2p orbitals.