Femtosecond Dynamics and Phase Relaxation of Electron Transfer Reaction in Double Metal Complex Crystals

为了进行倾斜研究，日本首次建造了飞秒腔倾倒的钛宝石激光器。我们成功地以可变的重复频率(10 kHz-76 MHz)将脉冲能量提高到10倍(35fs，20nJ/脉冲)，衍射效率(40-60%)。虽然我们已经尝试在泵浦-探测测量双金属络合物晶体和光导材料薄膜(如氧钛酞菁)晶体中的相位驰豫信号，但目前还不能在泵浦-探测测量中获得任何关于相位驰豫的信息。这是由于目前我们系统的泵浦-探测测量中的S/n比不好，以及整齐晶体中的一些热问题造成的。我们正在尝试将这种方法应用于稀释固体系统，并用这种激光系统组成的时间关联光子计数系统研究了客体掺杂晶体中的能量转移反应。在高掺杂Os^&lt；2+&Gt；：[Ru(Bpy)_3](Pf_6)_2晶体中，^3CT(Ru)的基质发射衰减为非指数衰减。衰变归因于不同的能量传递速率常数，这取决于激发的主客体距离，这是由于激发迁移通过主体分子的结果。通过随机模拟，得到最接近Os(II)的激发迁移率为1.2x10；lt；10；S；-1；-1；最接近Ru(II)的激发迁移率为3×10^8 S。金属中心最接近条件下的能量迁移和传递机制归结为电子交换作用。

For the tilted study, a femtosecond cavity-dumped Ti : Sapphire laser has been constructed for the first time in Japan. We have succeeded to increase a pulse energy to 10 times (35 fs, 20 nJ/pulse) with variable repetition rates(10 kHz-76 MHz) in a diffraction efficiency (40-60%). Although we have tried to measure phase relaxation signals in pump-probe measurements of double metal complex crystals and thin crystal films of photo-conducting materials such as oxotitanylphthalocyanine, we could not succeed yet to get any information of phase relaxation in pump-probe measurements at this moment. This is due to a bad s/n ratio in pump-probe measurement of present our system and some thermal problems in neat crystals. We are trying to apply this method to diluted solid systems.Energy transfer reactions in guest-doped crystals have also been investigated by means of time-correlated photon-counting consists of this laser system. In the case of highly doped Os^<2+> : [Ru(bpy)_3](PF_6)_2 crystal, the host emission decay of ^3CT(Ru) was non-exponential. The decay is ascribed to the various rate constants of energy transfer depending on the excited host-guest distances, which are changed as a result of excitation migration through the host molecules. By a stochastic simulation, rates are determined to be 1.2 x 10^<10> s^<-1> for the closest Os(II) and 3 x 10^8 s^<-1> for the excitation migration to the closest Ru(II). The mechanism of energy migration and transfer in the closest condition of metal centers are ascribed to electron exchange interaction.