1. Chapter 5 Molecular Orbital Theory

2. Interactions of two s orbitals: H2
Look at combinations of 1s wavefunctions:

3. Interactions of two s orbitals: H2

4. Interactions of two p orbitals

5. Interactions of two p orbitals

6. Interactions of two p orbitals

7. Interactions of two p orbitals: MO Diagram

8. Interactions of two d orbitals

9. Interactions of two d orbitals

10. Homonuclear Diatomics

12. Orbital Mixing
Orbitals of same symmetry interact. lower E orbital decreases in E. higher e orbital increases in E.

14. Evidence?

15. Evidence: Photoelectron Spectroscopy

16. What about different
atoms? How do you
know relative atomic
orbital energies?

17. More complicated:
Using symmetry and LCAO’s H2O
Look at what
happens to H 1s
orbitals

19. More complicated:
Using symmetry and LCAO’s H2O
Look at what
happens to H 1s
orbitals

20. More complicated:
Using symmetry and LCAO’s H2O

21. More complicated:
Using symmetry and LCAO’s H2O

22. 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

23. CH4 Hybrid Orbitals: Predict Orbital Energies

24. 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.