Excitation energy transfer and exciton-exciton annihilation in the isolated light-harvesting chlorophyll alb protein complex of spinach photosystem II (LHC II) has been studied by two-color absorption difference spectroscopy with femtosecond time resolution. The kinetic curves of the transient absorption changes at 680 nm show a remarkable intensity dependence which is ascribed to exciton-exciton annihilation. It is concluded that annihilation processes preferably occur among excited singlet states of Chl a molecules.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry