ABSTRACTThe intramolecular photoinduced energy and electron transfer within a fullereneoligothiophene-fullerene triad with nine thiophene units (C60-9T-C60) and an oligo(p-phenylene vinylene)-fullerene dyad with four phenyl groups (OPV4-C60) is investigated with femtosecond pump-probe spectroscopy with sub-10 fs and 200 fs time resolution in solvents of different polarity. Photoexcitation of the π-conjugated oligomer moiety in the triad and dyad results in an ultrafast singlet-energy transfer reaction to create the fullerene singlet-excited state with a time constant of 150-190 fs, irrespective of the polarity of the medium. In a polar solvent, intramolecular electron transfer occurs from the oligomer moiety to the C60 moiety with a time constant of 10-13 ps as a secondary reaction, subsequent to the ultrafast singlet-energy transfer. The charge-separated state has a lifetime of 50-80 ps and recombines to the ground state.
Photoinduced Energy and Electron Transfer in a Cofacial Aluminum(III) Porphyrin – Phosphorus(V) Porphyrin Heterodimer
