Vibrational and Structural Dynamics in Complex Liquids

化学部授予麻省理工学院的这项初创奖学金支持安德烈·托克马科夫教授的研究。这项研究的主题是利用一维和二维振动光谱研究水和水溶质的超快动力学。纯净水和可变的H2O/D2O混合物的集体动力学将通过对非均质性和振动之间的耦合机制敏感的二维拉曼实验来探索。对张量响应的所有元素的偏振选择一维拉曼实验将被用于分离旋转、平移和耦合的分子间运动。红外泵浦-探测实验将用于探测溶质-溶剂相互作用。水中的系统实验将被用来理解分子间松弛的机制，并确定水的哪些运动优先耦合到溶质振动。这个项目的结果将有助于理解分子之间和分子内相互作用的细节，并有助于解释这些相互作用如何导致材料整体表现出的性质和整体化学反应活性。这样的理解可以导致预测物质凝聚态中化学反应和物理过程的结果的能力。

This starter grant award of the Chemistry Division to the Massachusetts Institute of Technology supports the research of Professor Andrei Tokmakoff. The theme of the research is the investigation of the ultrafast dynamics of water and aqueous solutes using one- and two-dimensional vibrational spectroscopies. The collective dynamics of neat water and variable H2O/D2O mixtures will be probed using two-dimensional Raman experiments which are sensitive to heterogeneity and to the mechanism of coupling between vibrations. Polarization-selective one-dimensional Raman experiments on all elements of the tensorial response will be used to separate rotational, translational, and coupled intermolecular motions. Infrared pump-probe experiments on aqueous solutes will be used to probe solute-solvent interactions. Systematic experiments in water will be used to understand the mechanism of intermolecular relaxation and determine which motions of water preferentially couple to solute vibrations.Results from this project will help understand the details of interactions between and within molecules and will help explain how these interactions give rise to the properties and overall chemical reactivity displayed by materials in the bulk. Such an understanding can lead to the ability to predict the outcome of chemical reactions and physical processes in condensed phases of matter.