MICROSCOPIC DYNAMICS OF PHOTOPRODUCED GEMINATE MOLECULES IN SOLVENT CAGE

1.猝灭剂浓度对溶液中双分子反应速率的影响在较宽的猝灭剂浓度范围内，研究了香豆素151-N，N-二甲基苯胺在苯甲醚中的分子间电子转移时间分辨荧光猝灭反应，用Smoluchowski汇项模型拟合了实验衰减曲线。在由荧光剂和猝灭剂分子间相互作用势导出的初始条件下，用随机游动法求解扩散方程。强调了猝灭剂分子的“自由基分布函数”而不是“随机粒子分布”对于解释猝灭剂浓度较高和猝灭时间较早时的猝灭动力学的重要性。2.溶液中对氨基苯二硫化物的光解离和双生动力学通过测量皮秒时间分辨吸收光谱，研究了对氨基苯二硫化物和对氨基苯硫醇在不同溶剂中的光解离。对氨基苯硫基在非极性溶剂中的双硫化反应，在几十皮秒的延迟时间内，观察到成对复合引起的对氨基苯硫基自由基的衰减。除了轻微的变化，在光谱形状的thiyle自由基，上升的宽吸收带，这应该被分配给自由基二聚体，以下的双生复合。

1.Effects of Quencher Concentration on Bimolecular Reaction Rate in SolutionThe time resolved fluorescence quenching reaction via intermolecular electron transfer for coumarin 151-N,N-dimethylaniline system in anisole has been studies in the broad range of quencher concentrations.The Smoluchowski sink term model was used to fit the experimental decay curves. The random walk method has been used to solve the diffusion equation under the initial conditions derived from the intermolecular portential between fluorescer and quencher. The importance of the "radical distribution function" instead of " random particle distribution" of the quencher molecules, for explanation of the quenching dynamics at earlier times and higher quencher concentrations, is emphasized.2.Photodissociation and Geminate Dynamics of Aminophenydisulfide in SolutionMeasuring picosecond time resolved absorption spectra, the photo-dissociation of p-aminophenyldisulfide and p-aminophenylthiol in various solvents has been investigated. In tens of picosecond delay times a decay of p-aminophenylthiyl radical ascribed to the geminate recombination was observed for p-aminophenyldisulfied in nonpolar solvents. In addition to a slight change in the spectral shape of thiyle radical, the rise of the broad absorption band, which should be assigned to the radical dimer, follows to the geminate recombination.