Large reorganization energy of pyrrolidine-substituted perylenediimide in electron transfer
Large reorganization energy of pyrrolidine-substituted perylenediimide in electron transfer
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DOI：
10.1021/jp068893q
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发表时间：
2007-03
影响因子：
3.7
通讯作者：
Y. Shibano;T. Umeyama;Y. Matano;N. Tkachenko;H. Lemmetyinen;Y. Araki;O. Ito;H. Imahori
中科院分区：
文献类型：
--
作者：
Y. Shibano;T. Umeyama;Y. Matano;N. Tkachenko;H. Lemmetyinen;Y. Araki;O. Ito;H. Imahori
利用时间分辨瞬态吸收光谱和荧光寿命测量研究了一种供电子的吡咯烷取代的苝酰亚胺-C60键合二联体的激发态动力学。通过在对苝二酰亚胺部分的选择性激发下的皮秒瞬态吸收测量，已经在极性溶剂中成功地检测到电荷分离态（即，苯甲腈、吡啶和邻二氯苯），证明了发生了从苝二酰亚胺到C60部分的光诱导电子转移。相反，在非极性溶剂（即，甲苯）时，发生从苝二酰亚胺到C60的单重态-单重态能量转移，然后发生到C60激发三重态的系间跃迁，随后发生三重态-三重态能量转移，得到苝二酰亚胺激发三重态。极性溶剂中电荷复合的速率常数与电荷分离的速率常数相当甚至更大，这与极性溶剂中的电荷分离速率常数有关。
Excited-state dynamics of an electron-donating, pyrrolidine-substituted perylenediimide-C60 linked dyad have been investigated by means of time-resolved transient absorption spectroscopy and fluorescence lifetime measurements. By the picosecond transient absorption measurements at a selective excitation of the perylenediimide moiety, a charge-separated state has been successfully detected in polar solvents (i.e., benzonitrile, pyridine, and o-dichlorobenzene), demonstrating the occurrence of photoinduced electron transfer from the perylenediimide to the C60 moiety. In contrast, in nonpolar solvents (i.e., toluene), singlet−singlet energy transfer takes place from the perylenediimide to the C60, followed by intersystem crossing to the C60 excited triplet state and subsequent triplet−triplet energy transfer to yield the perylenediimide excited triplet state. Rate constants of the charge recombination in the polar solvents are found to be comparable to or even larger than those of the charge separation, whic...