CHEM 442 Lecture 36 Problems
36-1. Starting from the transition dipole moment, derive selection rules of electronic
transitions. What is a Franck-Condon factor?
36-2. What does a long vibrational progression with a weak 0-0 transition in the
electronic absorption spectrum of a diatomic molecule imply with regard to the shapes
and placements of two potential energy curves involved?
36-3. What does a short vibrational progression with a dominant 0-0 transition in the
electronic absorption spectrum of a diatomic molecule imply?
36-4. What does a long vibrational progression with alternating intensities in the
electronic absorption spectrum of a diatomic molecule imply?
36-5. What does a vibrational progression that becomes structureless after a certain
threshold imply?
36-6. Explain why the normal modes that give rise to a vibrational progression in an
electronic absorption spectrum are totally symmetric.
36-7. Explain why only the totally symmetric normal modes are selectively enhanced in
their intensities in resonance Raman spectra.
36-8. What is Kasha’s rule?
36-9. What is fluorescence quenching?
36-10. What is vibronic coupling?
36-11. Justify the Laporte rule and explain why the d-d transition in [Ni(H2O)6]2+ is
orbitally forbidden.
36-12. Explain how the d-d transition of 36-11 becomes vibronically allowed.
36-13. Explain why the 0-0 transition in the A1gB2u electronic absorption is not
observed in benzene.
36-14. Explain why a hot band from the v = 1 state of an E2g normal mode is observed in
the A1gB2u electronic absorption of benzene.