Chapter 5 Molecular Orbital Theory
Interactions of two s orbitals: H2 Look at combinations of 1s wavefunctions:
Interactions of two s orbitals: H2
Interactions of two p orbitals
Interactions of two p orbitals
Interactions of two p orbitals
Interactions of two p orbitals: MO Diagram
Interactions of two d orbitals
Interactions of two d orbitals
Homonuclear Diatomics
Orbital Mixing Orbitals of same symmetry interact. lower E orbital decreases in E. higher e orbital increases in E.
Evidence?
Evidence: Photoelectron Spectroscopy
What about different atoms? How do you know relative atomic orbital energies?
More complicated: Using symmetry and LCAO’s H2O Look at what happens to H 1s orbitals
More complicated: Using symmetry and LCAO’s H2O Look at what happens to H 1s orbitals
More complicated: Using symmetry and LCAO’s H2O
More complicated: Using symmetry and LCAO’s H2O
In general: Use Symmetry Adapted Linear Combinations of Atomic Orbitals (SALCs) for terminal atoms and combine with atomic orbitals (AOs) of central atom. Examples of sigma-only bonding SALCs: (see file SigmaMOdiagramsforTMs; see SALC_O For SALCs for sigma and pi bonding. Td C3v
CH4 Hybrid Orbitals: Predict Orbital Energies
CH4 MOs: SALC’s for H’s in Td point group CH4 MOs: SALC’s for H’s in Td point group. Then relate those to C’s orbitals to predict MOs.