Study of Low Frequency Collective Modes of Hydrogen Bonded Liquids in Bulk Mixtures and at the Liquid/Solid Interface Using Time Domain THz and THz-SHG Spectroscopy

加州大学河滨分校的哈里·汤姆教授得到了分析和表面化学计划的支持，利用太赫兹光谱学研究氢键液体和固/液界面。利用仪器和数据分析的进步，通过将范围扩展到低至0.002太赫兹，将改进时域太赫兹光谱学。其次，将使用记忆核形式来分析低频特征，以提取集体分子取向、角速度以及潜在的交叉耦合强度。这些方法将被用于研究离子溶液以及导致生物分子(如DNA)的日益复杂的分子的溶液。最后，将发展太赫兹泵浦和时间分辨二次谐波产生来研究固/液界面(即吸附在水/硅界面上的苯酚衍生物)。太赫兹光谱学是最近才出现的一种探测极低频率运动的新方法，这一新信息有望对理解凝聚态液体、界面以及生物介质具有重要意义。

Professor Harry Tom of the University of California Riverside is supported by the Analytical and Surface Chemistry Program to use terahertz spectroscopy to study hydrogen bonded liquids and the solid/liquid interface. Time-domain terahertz spectroscopy will be improved by extending the range to as low as 0.002 THz using instrumental and data analysis advances. Secondly the low frequency features will be analyzed using memory kernal formalism to extract collective molecular orientation, angular velocity, and potentially also cross-coupling strengths. These methods will be used to study ionic solutions as well as solutions of increasingly complex molecules leading up to biomolecules such as DNA. Lastly, THz pump and time-resolved second harmonic generation will be developed for the study of solid/liquid interfaces (namely, phenol derivatives adsorbed at the water/silica interface). Terahertz spectroscopy has only recently come on the scene as a new method for probing very low frequency motions, and this new information promises to be of importance in understanding condensed liquids, interfaces, as well as biological media.