Synthesis of Natural Carotenoid-Modified Pyropheophorbide Dyads for Investigation of Carotenoid-Chlorophyll Excited State Interactions

Abstract
Two sets of new fucoxanthin or zeaxanthin-linked pyropheophorbides were prepared to compare the intramolecular excited-state interactions. Fucoxanthin acts as a better antenna toward pyropheophorbide by transferring singlet energy from its S1-state, while zeaxanthin is a poorer antenna and quenches the S1-state of the pyropheophorbide possibly by reverse energy transfer.