Visible absorption bands of β-apo-8′-carotenal, citranaxanthin, and reticulataxanthin Schiff's bases are measured and analyzed in relation to the visual chromophore, retinal Schiff's base. The former shows a strong red shift of the absorption maxima upon protonation in ethanol, and the magnitude of the band shift is comparable to that of retinal Schiff's base. Molecular orbital analysis of the ground and excited state electronic structures of both types of Schiff's bases suggests the usefulness of carotenal Schiff's bases as a model for comparative studies with visual chromophore.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Atomic and Molecular Physics, and Optics