xi D.Carotenoid Radical Cations 163 E.Carotenoid-Iodine Complexes 164 F.Biological Relevance 166 References 166 Chapter 9:Excited Electronic States,Photochemistry and Photophysics of Carotenoids Harry A.Frank and Ronald L.Christensen A.Introduction …167 B.Conceptual Background and Terminology … 168 1.Electronic structure and electronic states 169 2.Electronic transitions 169 3.Interconversions and loss of excitation energy *中94中1中”0卡+04”*卡中””*中49*卡中4“中 171 4.Exciton interactions 171 5.Energy transfer 171 6.Quantum yield 172 C.Absorption Spectroscopy 172 D.Fluorescence Spectroscopy 176 E.Other Optical Techniques and Aspects 178 1.Pump-probe spectroscopy 2.Two-photon spectroscopy 179 3.Resonance Rar nan spectre oscopy 小1 180 F.Experimental Considerations. 181 1.Purity of carotenoids 181 2.Fluorescence spectral corrections 182 3.Band-pass corrections 182 4.Gaussian deconvolution 82 5.Excitation spectra... 18 6.Correlation of absorption and excitation spectra 3 7.Quantum vields................. 184 8.Solvents...... 184 G.Recent Developments........ 185 1.Geometrical isomerization 185 References 186xi D. Carotenoid Radical Cations ……………………………………………….. 163 E. Carotenoid-Iodine Complexes …………………………………………….. 164 F. Biological Relevance ………………………………………………………... 166 References ……………………………………………………………………… 166 Chapter 9: Excited Electronic States, Photochemistry and Photophysics of Carotenoids Harry A. Frank and Ronald L. Christensen A. Introduction ………………………………………………………………… 167 B. Conceptual Background and Terminology ……………………………….. 168 1. Electronic structure and electronic states ………………………………. 169 2. Electronic transitions …………………………………………………… 169 3. Interconversions and loss of excitation energy ………………………… 171 4. Exciton interactions …………………………………………………….. 171 5. Energy transfer …………………………………………………………. 171 6. Quantum yield ………………………………………………………….. 172 C. Absorption Spectroscopy ………………………………………………….. 172 D. Fluorescence Spectroscopy ………………………………………………… 176 E. Other Optical Techniques and Aspects …………………………………… 178 1. Pump-probe spectroscopy ………………………………………………. 178 2. Two-photon spectroscopy ………………………………………………. 179 3. Resonance Raman spectroscopy ………………………………………... 180 F. Experimental Considerations ……………………………………………… 181 1. Purity of carotenoids ……………………………………………………. 181 2. Fluorescence spectral corrections ………………………………………. 182 3. Band-pass corrections …………………………………………………... 182 4. Gaussian deconvolution ………………………………………………… 182 5. Excitation spectra ……………………………………………………….. 183 6. Correlation of absorption and excitation spectra ……………………….. 183 7. Quantum yields ………………………………………………………….. 184 8. Solvents …………………………………………………………………. 184 G. Recent Developments ………………………………………………………. 185 1. Geometrical isomerization ……………………………………………… 185 References ……………………………………………………………………… 186