Hybridization of Atomic Orbitals

Introduction to Hybridization

• Definition: Hybridization is the process of combining atomic orbitals to create hybrid orbitals.
• Examples:
  • sp3 hybrid orbital: Combination of 1 s orbital and 3 p orbitals (s1p3).
  • sp2 hybrid orbital: Combination of 1 s orbital and 2 p orbitals.
  • sp hybrid orbital: Combination of 1 s orbital and 1 p orbital.
  • d2sp3: Combination of 2 d orbitals, 1 s orbital, and 3 p orbitals.

Atomic Orbitals

• s Orbital:
  • Shape: Spherical.
  • Function: Indicates probability of finding an electron.
  • Note: Electrons behave as particles and waves; precise location is uncertain (Heisenberg's Uncertainty Principle).
• p Orbitals:
  • Types: Three orientations - px (x-axis), py (y-axis), pz (z-axis).

Hybridization of Carbon

• Electron Configuration: 1s² 2s² 2p².
• sp3 Hybrid Orbital:
  • Formation: Utilizes 4 orbitals (1s and 3p).
  • Energy Characteristics: Closer to 2p due to 75% p character.
  • Electron Placement: Electrons added one at a time to degenerate orbitals (same energy).
• sp2 Hybrid Orbital:
  • Formation: Uses 1 s and 2 p orbitals, leaving 1 unhybridized p orbital.
  • Energy Characteristics: Closer to 2p, 67% p character.
  • Electron Configuration: 3 hybrid orbitals each with 1 electron.
• sp Hybrid Orbital:
  • Formation: Uses 1 s and 1 p orbital, leaving 2 unhybridized p orbitals.
  • Energy Characteristics: 50% s and 50% p character, energy in between s and p orbitals.

Hybrid Orbital Characteristics

• Formation: Mixing n atomic orbitals leads to n hybrid orbitals.
• Bond Formation:
  • Sigma Bonds: Formed from overlap of hybrid orbitals.
  • Pi Bonds: Formed from unhybridized p orbitals.
  • Sigma bonds are stronger than pi bonds.

Bond Characteristics

• Single Bonds: Contain 1 sigma bond.
• Double Bonds: Contain 1 sigma bond and 1 pi bond.
• Triple Bonds: Contain 1 sigma bond and 2 pi bonds; stronger but shorter than single bonds.
• Strength Comparison: Triple bonds > Single bonds due to more bonds; sigma > pi bond in individual strength.

Example Problem

• To determine the number of sigma and pi bonds:
  • Count each bond as containing 1 sigma bond.
  • Every double bond adds 1 pi bond.
  • Example Structure: 7 sigma bonds, 2 pi bonds.

These notes summarize key concepts of orbital hybridization, types of orbitals, and their role in bond formation, providing a foundational understanding for further exploration in chemistry.