Elucidation of Dynamics of Electron Transfer Process in Condensed Phases

为了阐明分子内核置换和溶剂动力学对ET速率的影响，在以下供体-受体连接的化合物中研究了分子内ET过程。(1)研究了M（II）-Rh（III）（M=Ru和Os）双核配合物中的光致电子转移速率和反电子转移速率与距离、溶剂、温度和能隙的关系。结果表明，铑配合物中的大核位移对电子转移速率有显著影响。(2)用高密度激光激发Ru（II）双核配合物产生双激发态。两个MLCT态之间发生三重态-三重态湮灭，形成电荷分离态[Ru（I）-Ru（III）]，产率为40%。电荷分离和电荷复合的距离依赖性已被检查。(3)观察到混合价络合物Ru（II）-M（III）（M=Ru和Os）中Ru-MLCT激发态的快速淬灭。所得产物为混合价态的同分异构体Ru（III）-Os（II），其经历反ET过程以再现基态。这些ET率的能隙和温度依赖性进行了研究。(4)用近红外激光脉冲激发混合价配合物Ru（II）-M（III）（M=Ru和Os）的MMCT带，观察到光学产生的混合价异构态的反ET过程。然而，异构体态的低量子产率（-0.2）表明大多数弗兰克-康登态在弛豫之前会衰变到基态。(5)在各种溶剂中测量了锌卟啉-二氯卟啉二元体系的电荷分离和电荷复合速率。电荷复合率随溶剂的变化在目前的非绝热ET理论中得到了很好的理解。分子内重组能为0.175eV，电子相互作用能为14 meV。

To elucidate the effects of both intramolecular nuclear displacement and solvent dynamics on ET rates, intramolecular ET processes have been studied in the following donor-acceptor linked compounds.(1) The dependencies of distance, solvent, temperature, and energy gap on the photoinduced and back ET rates in M (II) -Rh (III) (M=Ru and Os) dinuclear complexes have been examined. It is concluded that the large nuclear displacement in the rhodium complexes dominantly affected the ET rates.(2) The high-density laser excitation of a Ru (II) dinuclear complex was used to produce a doubly excited state. A triplet-triplet annihilation between two MLCT states occurred to form a charge-separated state, [Ru (I) -Ru (III)], with 40% in a production yield. The distance dependence of the charge-separation and charge recombination have been examined.(3) Rapid quenching of an Ru-MLCT excited state in the mixed-valent complexes, Ru (II) -M (III) (M=Ru and Os), was observed. The resulting product was the mixed-valence isomer state, Ru (III) -Os (II), which underwent back ET process to reproduce the ground state. Energy gap and temperature dependence of these ET rates have been studied.(4) On the excitation of MMCT bands in mixed-valent complexes, Ru (II) -M (III) (M=Ru and Os), with a near-IR laser pulse, a back ET process from an optically generated mixed-valence isomer state was observed. However, the low quantum yield (-0.2) of the isomer state suggests that most of Franck-Condon states decayd to the ground state before they relaxd.(5) The charge-separation and charge-recombination rates in Zinc chlorin-porphrin dyads have been measured in a variety of solvent. The variation of the charge-recombination rates with solvent was well understood in terms of current nonadiabatic ET theory. The intramolecular reorganization energy was estimated 0.175eV and the electronic interaction energy was 14meV.