Real-time probing of Energy Dissipation Processes in Solvated Clusters

溶剂化团簇中能量耗散过程的实时探测

• 批准号: 08454177
• 负责人: OHSHIMA Yasuhiro
• 金额: $ 4.74万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454177/
• 关键词: Clusters; ps Time-Resolved Spectroscopy; Solvation; Energy Dissipation; Laser-Induced Fluorescence; Charge-Transfer; Inter-System Crossing; 電子移動反応; 系間交差

The present research project aims to microscopic understanding on the energy dissipation processes in solvated clusters through ultrafast time-resolved measurements. Owing to the improvement in the experimental setup, such as the vacuum chambers and laser systems, the following results have been achieved.1. The 1 : 1 cluster of 9,9'-bianthryl (BA) with water has been studied for detailed characterization of the twisted intramolecular charge transfer (TICT) reaction in BA.The torsional potential of BA in the cluster has been determined form the laser-induced-fluorescence observation of the torsional progressions. The potential in the cluster is much different from that in the monomer, indicating considerable modification in the electronic character of BA by complexation, as well as steric repulsion between BA and water. The ps time-resolved fluorescence measurements have shown that the TICT rate has no appreciable dependence on excitation energy or solvent isotopic substitution. This ob … More servation confirms that the TICT reaction proceeds via "sequential" mechanism ; the initially prepared level is predominately coupled to intermediate levels with high vibrational excitation of torsional motion, which further relax to the final levels in the charge-separated state. This result demonstrates the importance of the torsional motion in the dynamics of TICT reactions.2. The water-solvated clusters of 9-acridone (AD) have been studied to explore the microscopic solvation effect on inter-system crossing (ISC) in AD.The fluorescence quantum yield is greatly enhanced with increasing order of solvation. Especially, drastic change with>200-fold increase caused by addition of only one water to the monomer indicates the crossover of the reaction mechanism form the direct ISC to the second-order ISC.Structural characterization by JR-UV double resonance spectroscopy combined with ab initio MO calculation has shown that water is hydrogen-bonded to C=O of AD in the 1 : 1 cluster. These results validates the site-selective microsolvation effect on ISC. Less

本研究项目的目的是通过超快时间分辨的测量值对解决簇中的能量耗散过程的了解。由于实验设置的改进，例如真空腔和激光系统，因此已实现以下结果。1。已经研究了带有水的9,9'-二甲晶（Ba）的1：1簇，以详细描述BA中扭曲的分子内电荷转移（TICT）反应。已确定了Ba在群集中的扭曲电位，已确定了激光诱导的溶液诱导的交流液的荧光观察。簇中的电位与单体中的电位大不相同，表明通过络合物的电子特征以及BA和水之间的空间排斥在外的考虑修改。 PS时间分辨的荧光测量结果表明，TICT速率对兴奋能量或溶解性同位素取代没有明显的依赖。这项OB…更多的服务证实了Tict反应是通过“顺序”机制进行的。最初制备的水平主要耦合到中间水平，并具有高振动运动的振动兴奋，这进一步放松到电荷分离状态下的最终水平。该结果证明了扭转运动在TICT反应动力学中的重要性。2。 9- acri酮（AD）的水溶解簇已经研究了，以探索AD中对系统间交叉（ISC）的微观溶液效应。随着解决方案的增加，荧光量子产率大大增强。尤其是，由于在一个月中仅添加一只水，引起的急剧变化表明，反应机制的交叉构成了二阶ISC的直接ISC。通过JR-UV双谐振光谱谱图结构的结构表征与Ab initio MO计算相结合，表明水是氢键添加到1：1：1：1 cluster的C = O的C = O中的c = o。这些结果验证了对ISC的现场选择性微覆盖效应。较少的

项目成果

H.Kohguchi,et al.: "Laser-induced-fluorescence spectra and olaservation of quantum beats in the A^1π^1-X^2π transition of the HCCS radical" Chemical Physics Letters. 254. 397-402 (1996)

H.Kohguchi 等人：“HCCS 自由基的 A^1π^1-X^2π 跃迁中的激光诱导荧光光谱和量子拍观测”《化学物理快报》254. 397-402 (1996)。

Y.Ohshima,et al.: "Rotational spectroscopy of jet-cooled molecular ions and ion complexes" Chenical Physics Letters. 256. 635-640 (1996)

Y.Ohshima 等人：“喷射冷却分子离子和离子复合物的旋转光谱”《化学物理快报》。

M.Matumura, et al.: "Fourier-transform microwave spectroscopy of the argon-diacetylene van der Waals complex" Journal of Molecular Spectroscopy. 185. 178-184 (1997)

M.Matumura 等人：“氩-二乙炔范德华复合物的傅立叶变换微波光谱”《分子光谱学杂志》。

M.Matumura,et al.: "Fourier-transform microwave spectroscopy of the argon-diacetylene van der Waals complex" Journal of Molecular Spectroscopy. 185. 178-184 (1997)

M.Matumura 等人：“氩-二乙炔范德华复合物的傅里叶变换微波光谱”《分子光谱学杂志》。

Y.Ohshima,et al.: "Rotational spectroscopy of jet-cooled molecular ions and ion complexes" Chemical Physics Letters. 256. 635-640 (1996)

Y.Ohshima 等人：“喷射冷却分子离子和离子复合物的旋转光谱”《化学物理快报》。