Singlet Excited States and the Light‐Harvesting Function of Carotenoids in Bacterial Photosynthesis

Abstract

Abstract— The recent results of stationary‐state and time‐resolved absorption, fluorescence and Raman spectroscopies of some typical carotenoids are summarized. Theoretical analyses of carotenoid singlet states and of carotenoid‐to‐bacteriochlorophyll singlet‐energy transfer are also included. On the bases of the energies, the lifetimes and other properties of singlet excited states of the carotenoids in solution and bound to the light‐harvesting complexes, the energetics and the dynamics of the light‐harvesting function in purple photosynthetic bacteria are discussed with emphasis on the 2A g and B u + states.