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 A1gB2u 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 A1gB2u electronic absorption of benzene.