Photoinduced Electron Transfer of Dialkynyldisilane-Linked Zinc Porphyrin–[60]Fullerene Dyad

A zinc porphyrin–fullerene dyad with a disilane as a σ-conjugated linker has been newly synthesized to evaluate the electron transfer ability of the oligosilane chain. Its photoinduced processes have been studied using the time-resolved fluorescence and absorption measurements. Photoexcitation of the dyad causes the energy and/or electron transfer from the excited singlet state of the ZnP to C60 moiety in polar solvents. The charge separation takes place as a final step in the excited-state process to yield the radical-ion pair with a radical cation on the zinc porphyrin and a radical anion on the fullerene, similar to other porphyrin–fullerene dyads. Its lifetime has been estimated to be 0.43–0.52 μs on the basis of the decay rate of the fullerene radical anion in polar solvents.