Elementary process from electronic energy to thermal energy and the quantum effect to molecular diffusion process

采用激光诱导瞬态光栅技术研究溶液相分子动力学：1.利用温度透镜、温度光栅、声峰位移法、分子加热器-分子温度计系统等新方法，揭示了溶液相电子能量向热能的基本能量传递过程。我们发现分子间能量转移的时间分布可用双指数函数表示。快速过程代表从光激发分子到最近的溶剂分子的能量转移。较慢的过程代表溶剂分子之间的热传导过程。研究了甜菜碱-30在不同溶剂中的扩散速率与分子间相互作用的关系。2.利用瞬态光栅技术研究了化学反应性分子的扩散过程。我们发现反应中间物种的扩散过程与化学稳定分子的扩散过程有很大的不同。自由基扩散缓慢的原因是自由基与溶剂分子之间的分子间相互作用增强。3.从焓变和体积变化的角度研究了几种蛋白质的动力学。

The laser induced transient grating was used to study the molecular dynamics in solution phase.1.The elementary energy transfer process from the electronic energy to the thermal energy was revealed by newly developed methods such as the temperature lens, temperature grating, acoustic peak shift method, and molecular heater-molecular thermometer system. We found that the time profile of the intermolecular energy transfer was expressed by a bi-exponential function. The fast process represents the energy transfer from the photoexcited molecule to the nearest solvent molecules. The slower process represents the heat conduction process among the solvent molecules. The relationship between the transfer rate and the intermolecular interaction was revealed for Betaine-30 in various solvents.2.Molecular diffusion processes of chemically reactive molecules were studied by the transient grating technique. We found that the diffusion process of the reaction intermediate species was very much different from that of chemically stable mole cules. The origin of the slow diffusion of the radicals was attributed to the enhanced intermolecular interaction between the radical and the solvent molecules.3.Several protein dynamic were studied using a new measurement we have developed from a point of view of the enthalpy change and the volume change.