University:
York University
Course:
CHEM 1000 | Chemical Structure
Academic year:

2021
Views:

261

Pages:

3
Author:

Niklas

Lecture 2 (01/14/21) Bonding Theories Valence Bond Theory Molecular Orbital Theory (More Accurate) Intermolecular Forces Electron Properties: e- behave like waves - "Wave Function" Constructive vs. Destructive Covalent bonds are formed by constructive interference of e- waves Bonding (Formation) Anti-Bonding (Destabilization) TWO KEY EXPANSION CONCEPTS: Hybrid Orbitals/Hybridization: Overlapping of atomic orbitals to form hybrid orbitals Resonance: e- in π orbitals can be delocalized beyond indiv. bonds Atomic Orbitals: l Shape 0 s-orbital 1 p-orbitals (3) 2 d-orbitals 3 f-orbitals *Waves that are opposite will cancel each other out. Case #1: ψ = c1ψ₁ + c2ψ₂ ψ₁ = 1s(A) ψ₂ = 1s(B) Bonding: ψ = c1ψ₁ + c2ψ₂ Anti-bonding: ψ = c1ψ₁ - c2ψ₂ Bond Order (BO): BO = ( # Bonding e- - # Anti-bonding e- ) / 2 Case #2: p(A) + p(A) → σ/σ* (MO) Case #3: p(A) + p(A) → π/π* (MO) *In π-orbitals, e- bonds are not directly pulling the two nuclei together, but they're above and below. Think like a hamburger (bun in the buns).