Lecture on Hybridization of Atomic Orbitals

Introduction to Hybridization

• Importance of hybridization in understanding atomic structures.
• Builds on Lewis dot structures.

Lewis Dot Structures

• Beryllium Hydride Example:
  • Beryllium (Be) has 2 valence electrons.
  • Hydrogen (H) has 1 valence electron each, total 2 H atoms.
  • Bond formation requires Be to have 2 unpaired electrons.
  • Use of electron energy diagrams to understand unpaired electrons.

Hybridization Concept

• Beryllium Hybridization:

  • Be 2s and one 2p orbital hybridize to form sp hybrid orbitals.
  • These sp orbitals allow Be to have 2 unpaired electrons.

• General Hybridization:

  • Involves s and p orbitals, sometimes d orbitals in higher elements.
  • Hybridization allows correct number of unpaired electrons and spacing.

Orbital Overlap and Bond Formation

• Explanation of orbital shapes: s, p, and hybrid sp orbitals.
• Bonds form through overlap of orbitals:
  • s orbitals are spherical.
  • p orbitals are dumbbell-shaped.
  • sp orbitals have a mixed character.

Examples of Hybridization

Boron Trihydride (BH3)

• Lewis Structure: Boron needs 3 unpaired electrons.
• Hybridization: Boron undergoes sp2 hybridization.

Methane (CH4)

• Lewis Structure: Carbon needs 4 unpaired electrons.
• Hybridization: Carbon undergoes sp3 hybridization for tetrahedral geometry.

Ammonia (NH3)

• Lewis Structure: Nitrogen needs 3 unpaired electrons.
• Hybridization: Nitrogen undergoes sp3 hybridization despite having 3 unpaired electrons naturally. This is to achieve correct electron spacing.

Water (H2O)

• Hybridization: Oxygen is sp3 hybridized for tetrahedral electron geometry.

Phosphorus Pentachloride (PCl5)

• Phosphorus needs more than 4 bonds:
  • Usage of d orbitals for sp3d hybridization.

Sulfur Hexafluoride (SF6)

• Sulfur uses sp3d2 hybridization to accommodate 6 bonds.

Conclusion on Hybridization

Reasons for Hybridization

1. Obtain the correct number of unpaired electrons to facilitate bonding.
2. Proper spatial arrangement of electron pairs to minimize repulsion.

• This lecture focused on single-bond formation; next will cover multiple bonds (double, triple).

These notes provide a structured overview of the lecture's main points, allowing for easy review and understanding of hybridization and its role in molecular structure.