A theoretical study of the interaction between inter-molecular proton transfer and internal rotation

本研究项目从理论上研究了分子间质子转移与内转动之间的相互作用。对于这个问题，一项实验研究已经报道了一种特殊的相互作用的存在，其中质子转移反应被内转动的激发所增强。然而，这种相互作用的详细机制还完全不清楚。在本项目中，开发了处理这一问题的新方法和计算机代码，并将其应用于5-甲基-9-羟基苯丙烯酮、2-甲基丙二醛和5-甲基-甲苯洛酮。所开发的方法和计算机实质上是对具有多个大振幅运动的系统的反应面哈密顿方法的扩展。在应用中，上述相互作用得到了肯定，并成功地分析了这种相互作用的详细机理。除了这一分析外，还发现了当内转动处于高激发态时的新事实。这是由于高激发旋转态的内转动激发阻碍了质子转移反应。本课题还对这一现象产生的原因和机理进行了分析。

This research project investigated theoretically the interaction between the inter-molecular proton transfer and the internal rotation. For this problem, an experimental research had already reported the existence of a peculiar interaction where the proton transfer reaction was enhanced by the excitation of the internal rotation. However, the detailed mechanism of this interaction has been completely unknown.In this project, new method and computer code to treat this problem were developed and were applied to the 5-methyl-9-hyodroxyphenalenone, 2-methyl-malonaldehyde and 5-methyl-tolopolone. The developed method and computer were essentially an extension of the Reaction Surface Hamiltonian method for the systems that have plural numbers of large amplitude motions. In the application, the interaction mentioned above was surely reconfirmed and the detailed mechanism of this interaction was also successfully analyzed. In addition to this analysis, a new fact was found when the internal rotation was in the highly excited states. It is that the proton transfer reaction was obstructed by the excitation of the internal rotation in the highly excited rotational states. In this project, the reason and the mechanism of this phenomenon were also analyzed.