Photoinduced electron transfer between fullerenes (C60 and C70) and phthalocyanines such as tetra-tert-butylphthalocyanine (H2TBPc) and its zinc derivative (ZnTBPc) in solution has been investigated with nanosecond laser photolysis method by observing the transient absorption bands in the visible/near-IR regions. By the predominant excitation of fullerenes with 532 nm laser light, slow rises of the transient absorption bands of phthalocyanine cation radicals and fullerene anion radicals were observed instead of the decays of the excited triplet states of fullerenes (TC60* and TC70*) in polar solvents. Electron-transfer from the phthalocyanines to TC60* or TC70* was confirmed. The quantum yield of the electron transfer via TC70* is higher than that via TC60*; ZnTBPc acts as stronger electron donor than H2TBPc. In nonpolar solvent, energy transfer from TC60* (and TC70*) to the phthalocyanines occurs predominantly as confirmed by the consecutive appearance of the triplet states of the phthalocyanines.

Photoinduced electron transfer between C60/C70 and zinc tetraphenylporphyrin (ZnTPP) in a polar solvent has been investigated with a nanosecond laser photolysis method by observing the transient absorption bands in the near-IR region. The transient absorption bands of the C60/C70 radical anion (C60 •-/C70 •-) in the near-IR region gave evidence of electron transfer for the system ZnTPP and C60/C70. In ZnTPP solution where C60 and C70 were photoexcited predominantly, electron transfer takes place from the ground state of ZnTPP to the triplet states of C60/C70 (3C60*/3C70*). In the concentrated ZnTPP solution where ZnTPP was predominantly photoexcited, the triplet state of ZnTPP donates the electron to the ground state of C60/C70, producing C60 •-/C70 •-. The efficiency of electron transfer via the 3C60*/3C70* route is higher than that via 3ZnTPP*.