"U.S.-Japan Cooperative Research: Structural Change and Vibrational Dynamics Studied by Ultrafast Spectroscopies"

该奖项将支持芝加哥大学的两个小组和冈崎分子科学研究所的两个小组在化学动力学方面的为期两年的合作研究项目。Graham R.Fleming教授和Jeffrey A.Cina教授将与Keitaro Yoshihara教授和Iwao Ohmine教授以及他们的同事一起研究溶液中的化学动力学。这些研究将超快光谱与理论和模拟相结合，旨在建立对溶剂如何影响化学反应速度和结果的详细了解。这类反应通常被模拟为发生在简单的一维势表面上。分子内其他自由度的振动要么被统计建模，要么被简单地忽略。溶剂在修饰势面和影响势面运动方面的作用通常被认为是不同的(“静态”和“动态”)。由于对振动动力学、真实势面和溶剂响应的各种时间尺度的忽视，阻碍了对简单化学过程的更真实的描述，例如光化学异构化。这个合作项目的目标是将美国和日本机构的团队的实验和理论优势结合起来，专门解决这些问题。芝加哥和冈崎的实验项目都代表了最先进的技术。它们在几个方面是互补的。芝加哥的团队比冈崎团队开发了更远的荧光光谱学，而冈崎团队则开发了独特的飞秒星团研究。FSCAR和拉曼光谱需要不同的设置，并将提供互补的信息。冈崎使用超大规模计算将电子结构和动力学建模结合在一起的技术已经得到了很好的发展，那里可用的巨大计算能力将使计算成为可能，而这在美国是无法想象的。看看这样的计算如何影响实验者的思维，这将是非常有价值的。美国和日本的小组在凝聚相动力学的分析研究方面都有很大的实力，同样，接触到日本的大型计算机计算对美国小组来说将是最有价值的。最后，作为该项目的重要组成部分，两名美国研究生将参加这项研究，他们每年都会花时间在日本的实验室里。

This award will support a two-year cooperative research project in chemical dynamics between two groups at the University of Chicago and two groups at the Institute for Molecular Science, Okazaki. Professors Graham R. Fleming and Jeffrey A. Cina will work with Professors Keitaro Yoshihara and Iwao Ohmine and their associates on studies of chemical dynamics in solution. The studies combine ultrafast spectroscopy with theory and simulation and are aimed at building up a detailed understanding of how solvents influence the rate and outcome of chemical reactions. Such reactions are often modeled as occuring on simple one- dimensional potential surfaces. The other degrees of freedom - in- tramolecular vibrations are either modeled statistically or simply ignored. The roles of the solvent in modifying the potential surface and in influencing motion along it are generally regarded as distinct ("static" and "dynamic"). The development of a more realistic description of simple chemical processes such as photochemical isomerization is hampered by ignorance of vibrational dynamics, of the true potential surface, and of the various time scales of the solvent response. The goal of this collaborative project is to combine the experimental and theoretical strengths of the groups at the U.S. and Japanese institutions to specifically address these questions. The experimental programs at both Chicago and Okazaki represent the state of the art. They are complementary in several ways. The groups at Chicago have developed fluorescence spectroscopy further than the Okazaki groups, while the Okazaki groups have developed unique femtosecond studies of clusters. The FSCAR and Raman spectroscopies require different set-ups and will give complementary information. The use of very large scale computing to combine electronic structure and dynamical modeling is well developed at Okazaki and the enormous computing power available there will allow calculations that could not be contemplated in the United States. It will be of great value to see how such calculations influence the thinking of experimentalists. Both the U.S. and the Japanese groups possess great strength in analytical studies of condensed phase dynamics and again, the exposure to the large computer calculations in Japan will be most valuable to the American groups. Finally, as an important part of the project, two U.S. graduate students will participate in the study, spending time each year in the Japanese laborator- ies.