Abstract

Time resolved studies of several groups on the reaction center of Photosystem II have revealed the presence of various kinetic and spectral components with lifetimes in the range of sub-ps to ns. While the longer lifetimes are generally ascribed to recombination of the long-lived radical pair P680⁺Pheo^- formed upon charge separation, the origin of the different sub-ps to ps components is controversial and processes as energy transfer, charge separation and exciton relaxation have been proposed. At room temperature e.g., charge separation has been reported to occur in 3 ps [1,2,3,4,5], but Klug and co-workers [6 and references therein] have found that radical pair formation occurs primarily (for ~70%) with a 21 ps time constant.

© 1996 Optical Society of America