Understanding Hybridization of Atomic Orbitals

Sep 1, 2024

Notes on Hybridization of Atomic Orbitals

Introduction to Hybridization

  • Hybridization: Combines atomic orbitals to create hybrid orbitals.
    • Example:
      • sp3 Hybrid Orbital: Combination of 1s and 3p orbitals (s1p3).
      • sp2 Hybrid Orbital: Combination of 1s and 2p orbitals.
      • sp Hybrid Orbital: Combination of 1s and 1p orbital.
      • d2sp3 Hybrid Orbital: Combination of 2d orbitals, 1s orbital, and 3p orbitals.

Overview of Orbitals

  • s-Orbital:
    • Shape: Spherical.
    • Represents the probability of finding an electron within an atom.
  • p-Orbitals:
    • Three types:
      • px: Oriented along x-axis.
      • py: Oriented along y-axis.
      • pz: Oriented along z-axis.

Electron Configuration of Carbon

  • Electron Configuration: 1s² 2s² 2p².
  • Valence Electrons: Carbon has four valence electrons.

sp3 Hybridization of Carbon

  • Uses all four orbitals (1s + 3p).
  • Character:
    • 25% s character (1 out of 4).
    • 75% p character (3 out of 4).
  • Energy Level: Closer to 2p than 2s.
  • Degenerate Orbitals: All four sp3 orbitals are of the same energy.
  • Hund's Rule: Place electrons one at a time in degenerate orbitals with parallel spins.

sp2 Hybridization

  • Formation: One s orbital and two p orbitals (leaving one p unhybridized).
  • Character:
    • 33% s character (1 out of 3).
    • 67% p character (2 out of 3).
  • Energy Level: Closer to 2p than 2s but less than sp3.
  • Forms three hybrid orbitals.

sp Hybridization

  • Formation: One s orbital and one p orbital (two unhybridized p orbitals).
  • Character:
    • 50% s character (1 out of 2).
    • 50% p character (1 out of 2).
  • Energy Level: Positioned between s and p orbitals.
  • Forms two hybrid orbitals.

Bonds Formation

  • Sigma Bonds: Formed from hybrid orbitals; every bond contains one sigma bond.
  • Pi Bonds: Formed from unhybridized p orbitals.
  • Bond Strength:
    • Triple bonds (1 sigma + 2 pi) are stronger than double (1 sigma + 1 pi) and single bonds (1 sigma).
    • Sigma bonds are stronger than pi bonds.

Summary of Bonds**

  • Types of Bonds:
    • Single Bond: 1 sigma bond.
    • Double Bond: 1 sigma + 1 pi bond.
    • Triple Bond: 1 sigma + 2 pi bonds.
  • Count Example:
    • For a given structure, count sigma (every bond = 1 sigma) and pi bonds (1 for each double bond).

Conclusion

  • Understanding hybridization is crucial for predicting molecular shapes and bond types.