1. Lecture 6 Vibrational spectra of complex molecules

2. R-Q-P

4. Gas Solid matrix Sharp peaks!

5. Liquid acetone Acetone in a solid matrix (*- admixtures) Sharp peaks!

6. Fermi Resonance Overtone: weak (forbiden) Resonance line: much stronger, shifted, and allowed Two conditions must be satisfied for the occurrence of Fermi Resonance: (1) the two vibrational states of a molecule transform according to the same irreducible representation of the molecular point group. (2) The energies of the transitions (accidentally) have almost the same energy.

7. Fermi Resonance Overtone Fundamental band