Intramolecular excitation energy transfer from visible-light absorbing chlorophyll derivatives to a near-infrared-light emitting boron dipyrromethene moiety

Chlorophyll-a derivatives were covalently linked with a πextended boron aza-dipyrromethene moiety. In the synthetic dyads, photoinduced energy transfer from the former visiblelight absorbing chlorin chromophore to the latter highly fluorescent unit in the near-infrared region was observed in a solution. The singlet-excited states of both the units were partially quenched by the charge-separated state, which was pronounced in polar organic solvents.