Picosecond Rotational Diffusion Studies Using Time-Resolved and Phase-Resolved Spectroscopy

这个项目是在分析和表面化学的一般领域，在光谱学和分离科学的子领域。电子光谱学提供了一种定量溶质的灵敏方法。由于电子光谱学现在可以获得更快的时间尺度，因此该工具可以更容易地用于获取结构信息。特别是，溶质的大小和形状决定了它的旋转扩散行为。中型有机分子在普通溶剂中的旋转扩散研究需要皮秒光谱和多重指数衰减响应信号的分辨率。Wirth教授和她的学生将测量溶质四烯的旋转扩散常数的三个组成部分，这将有助于评估从这种方法中获得结构信息的程度。然而，如果溶剂具有短程结构顺序，则溶剂的存在可能会限制所获得的溶质信息。为了解决这个问题，Wirth教授还将研究溶剂结构对溶质旋转扩散的影响。这些研究的结果有望对分析光谱学和提高对液体的基本认识都有价值。

This project is in the general area of analytical and surface chemistry and in the subfields of spectroscopy and separation science. Electronic spectroscopy affords a sensitive means of quantifying solutes. Because faster time scales are now accessible to electronic spectroscopy, this tool can be more readily used to obtain structural information. In particular, the size and shape of a solute determine its rotational diffusion behavior. Rotational diffusion studies of medium-sized organic molecules in common solvents require both picosecond spectroscopy and the resolution of multiple exponentially decreasing response signals. Professor Wirth and her students will measure the three components of the rotational diffusion constant of the solute tetracene which will enable an assessment of the extent to which structural information can be derived from this approach. However, if the solvent has short-range structural order, the presence of the solvent could potentially limit the solute information that is obtained. To address this issue, Professor Wirth will also study the effect of solvent structure on solute rotational diffusion. The results of these studies are expected to be valuable both to analytical spectroscopy and to an enhanced fundamental understanding of liquids.