Spectroscopic Study of Reaction Dynamics in Quantum Solids.

量子固体反应动力学的光谱研究。

基本信息

批准号：
10206203
负责人：
MOMOSE Takamasa
金额：
$ 15.3万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Solid hydrogen, known as a quantum crystal, shows extremely narrow spectral linewidths, which allow us to study interactions and dynamics of molecules imbedded in the solid by high-resolution spectroscopy. In order to study quantum effects on dynamics of molecules, we have investigated excited states and its relaxation processes, and chemical reactivities of molecules imbedded in solid parahydrogen using high-resolution rotation-vibration spectroscopy. Main results we obtained are as follows.(1) Relaxation processes of electronic and vibrational excited states in quantum solid.We found a T^4 temperature dependence of pure dephasing of vibrational excited states of molecules imbedded in the quantum solid. The T^4 temperature dependence is intrinsically different from the T^7 temperature dependence in classical medium. We also found that nuclear spin relaxation in the quantum solid is mainly caused by the intramolecular nuclear spin-rotation interaction and the one-phonon lattice rotation interaction.(2)Ions in quantum solid.In order to study ions in quantum solids, we irradiated solid hydrogen by gamma-ray. The irradiated solid showed new complicated spectral features with extremely narrow spectral linewidths. These spectral features are attributed to the transitions of hydrogen molecules induced by electric fields of ions produced in the solid.(3) Quantum effects on tunneling reaction.We have investigated X+H_2→XH+H type tunneling reaction in solid hydrogen by infrared spectroscopy. The tunneling reaction rate depends drastically on the zero-point vibration of reactants and products. Moreover, the rate depends significantly on the vibrational quantum number of reactants.

固体氢，被称为量子晶体，显示出极窄的光谱线宽，这使我们能够通过高分辨率光谱研究嵌入固体中的分子的相互作用和动力学。为了研究量子对分子动力学的影响，我们研究了激发态。利用高分辨率旋转振动光谱研究了固体仲氢分子的态及其弛豫过程以及化学反应性，我们得到的主要结果如下：（1）电子和振动激发的弛豫过程。我们发现嵌入在量子固体中的分子振动激发态的纯相移的 T^4 温度依赖性与经典介质中的 T^7 温度依赖性本质上不同。发现量子固体中的核自旋弛豫主要是由分子内核自旋-旋转相互作用和单声子晶格旋转相互作用引起的。(2)量子固体中的离子。为了研究量子固体中的离子，我们用伽马射线照射固体氢，照射后的固体表现出新的复杂光谱特征，这些光谱特征归因于固体中产生的离子电场引起的氢分子的跃迁。我们用红外光谱研究了固体氢中的X+H_2→XH+H型隧道反应，隧道反应速率很大程度上取决于固体氢的零点振动。此外，该速率很大程度上取决于反应物的振动量子数。