Abstract
The electronic-absorption spectra of all-trans carotenoids with different numbers of conjugated double bonds (n), including a spheroidene derivative (n=8), nurosporene (n=9), spheroidene (n=10), lycopene (n=11), anhydrorhodovibrin (n=12) and spirilloxanthin (n=13) were recorded at a high concentration (ODmax ** 20cm-1). After data-fitting we observed absorptions due to the **hidden** singlet states on the red side of the 1Bu+ absorption. The energies of those states exhibited a linear relation as function of 1/(2n+1). We assigned those states to the 2Ag-, 1Bu- and 3Ag- states based on comparison with our previously resonance-Raman and fluorescence results (Tokutake Sashima, et. al., J. Phys. Chem. B 2000, 104, 5011; Ritsuko Fujii, et. al., J. Phys. Chem. A 2001, 105, 5348). In the 2Ag- state, we observed a series of vibrational progression from **=0 to **=3.
