Hybridization of Atomic Orbitals

What is Hybridization?

• Hybridization: Combining atomic orbitals to create hybrid orbitals.
• Types of hybrid orbitals:
  • sp³: Combination of 1 s orbital and 3 p orbitals.
  • sp²: Combination of 1 s orbital and 2 p orbitals.
  • sp: Combination of 1 s orbital and 1 p orbital.
  • d²sp³: Combination of 2 d orbitals, 1 s orbital, and 3 p orbitals.

Types of Orbitals

• s Orbital:

  • Shape: Sphere
  • Represents the probability of finding an electron within an atom.
  • Electrons can behave as particles and waves.
  • Heisenberg’s Uncertainty Principle: Cannot precisely know the exact location of an electron.

• p Orbitals:

  • Three types oriented along different axes:
    • pₓ axis
    • pᵧ axis
    • p𝓏 axis

Hybridization of Carbon

• Electron Configuration of Carbon: 1s² 2s² 2p²
• Valence Electrons: 4

sp³ Hybrid Orbital

• Combines 1 s orbital with 3 p orbitals.
• Energy Level: Closer to 2p than 2s due to higher p character (75% p character, 25% s character).
• Degenerate Orbitals: Four orbitals with the same energy level.
• Electrons are added one at a time with parallel spins.

sp² Hybrid Orbital

• Combines 1 s orbital with 2 p orbitals, leaving one unhybridized p orbital.
• Energy Level: Closer to 2p than 2s (67% p character, 33% s character).
• Results in three hybrid orbitals each containing one electron.

sp Hybrid Orbital

• Combines 1 s orbital with 1 p orbital, leaving two unhybridized p orbitals.
• Energy Level: Intermediate between s and p orbitals (50% s character, 50% p character).
• Results in two hybrid orbitals.

Bond Formation

• Sigma Bonds (σ):

  • Formed from the overlap of atomic orbitals, often hybrid orbitals.
  • Every single bond comprises one sigma bond.

• Pi Bonds (π):

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

Strength and Length of Bonds

• Triple Bonds:

  • Stronger and shorter than single bonds due to the presence of two pi bonds.

• Comparison:

  • Sigma bonds are stronger than pi bonds.
  • Triple bonds are stronger than single bonds because they consist of multiple bonds.

Example

• Counting Sigma and Pi Bonds:
  • In a structure, each bond contains one sigma bond.
  • A double bond adds one pi bond.
  • Example: A structure with 7 sigma bonds and 2 pi bonds.