Hybridization of Atomic Orbitals

Introduction to Hybridization

• Definition: Hybridization is the process of combining atomic orbitals to form hybrid orbitals.

Types of Hybridization

• sp3 Hybrid Orbital:

  • Combines one s orbital and three p orbitals.
  • Has 25% s character and 75% p character.

• sp2 Hybrid Orbital:

  • Combines one s orbital and two p orbitals.
  • Has 33% s character and 67% p character.

• sp Hybrid Orbital:

  • Combines one s orbital and one p orbital.
  • Has 50% s character and 50% p character.

Understanding Atomic Orbitals

• s Orbital:

  • Shape: Spherical.
  • Represents the probability of finding an electron within an atom.

• p Orbitals:

  • Three types: p_x, p_y, p_z (aligned with x, y, and z axes, respectively).

Carbon Hybridization

• Electron Configuration of Carbon: 1s² 2s² 2p²
• Valence Electrons: Carbon has four valence electrons.
• sp3 Hybridization:
  • Uses all four orbitals (1 s and 3 p).
  • Energy level closer to 2p than to 2s.
  • Forms four degenerate orbitals.
• sp2 Hybridization:
  • Uses 1 s and 2 p orbitals.
  • One p orbital remains unhybridized.
  • Produces three hybrid orbitals with energy closer to 2p.
• sp Hybridization:
  • Uses 1 s and 1 p orbital, leaving two p orbitals unhybridized.
  • Results in two hybrid orbitals positioned between s and p.

Sigma and Pi Bonds

• Sigma Bonds:

  • Formed from the overlap of hybrid orbitals.
  • Every bond contains one sigma bond.

• Pi Bonds:

  • Formed from unhybridized p orbitals.
  • A double bond has one sigma and one pi bond.
  • A triple bond has one sigma and two pi bonds.

Bond Strength Comparison

• Triple Bonds: Stronger than single bonds due to three bonding interactions.
• Sigma Bonds: Stronger than pi bonds.
  • Easier to break a pi bond than a sigma bond.

Counting Sigma and Pi Bonds in Structures

• Every bond contains one sigma bond.
• Double bonds contribute one pi bond each.
• Example counting: if there are 7 sigma bonds and 2 pi bonds in a structure, simply count the bonds accordingly.