Photoinduced Electron Transfer in Donor-linked Fullerenes

我们首次成功地将介孔、介孔连接的卟啉二聚体作为光合多步电子转移模型加入到电荷分离单元中，制备了二茂铁-卟啉二聚体-富勒烯三元体。三价体揭示了光诱导电子从卟啉二聚体激发单重态转移到C_<60>，然后电荷从二茂铁转移到卟啉二聚体自由基阳离子，从而产生高量子产率（0.71-0.88）和长电荷分离寿命（16-83 μs）的铁离子- c <60>自由基离子对，这取决于溶剂。这里应该强调的是，用卟啉二聚体取代卟啉单体延长了目前三元化合物的电荷分离寿命，而没有显著降低量子产率。电荷分离寿命是由逐步电荷重组而不是直接电荷重组控制的。

We have prepared ferrocene-porphyrin dimer-fullerene triad where meso, meso-linked porphyrindimer is incorporated successfully into a charge separation unit as photosynthetic multistep electron transfer model for the first time. The triad reveals photoinduced electron transfer from the porphyrin dimer excited singlet state to the C_<60>, followed by charge-shift from the ferrocene to the porphyrin dimer radical cation, to produce the ferricenium ion-C<60> radical ion pair with a high quantum yield (0.71-0.88) as well as a long-lived charge-separated lifetime (16-83 μs) depending on the solvent. It should be emphasized here that the charge-separated lifetime of the present triad has been prolonged by replacing porphyrin monomer with porphyrin dimer without reducing the quantum yield significantly. The charge-separated lifetime is governed by stepwise charge recombination rather than direct charge recombination.