Chiroptical Spectroscopic Studies on Supramolecular Aggregates

有了这个奖项，化学系的化学结构，动力学和机制（CSDM-A）计划正在资助范德比尔特大学的Prasad Polavarapu教授研究“手性”分子-即与手性相关的分子。左旋手性分子和其右旋镜像之间的药理活性差异使得有必要将这些分子彼此分离以研究它们的性质。 Polavarapu博士的团队专门研究手性表面活性剂分子，这些分子形成具有封装特性的特殊聚集体结构（例如用于药物输送）。他们寻求更好地了解这些分子的特性，以便更好地控制和使用。来自范德比尔特和田纳西州立大学的学生通过与Nsoki Phambu博士的合作参与，预计将为对STEM学科感兴趣的本科生提供宝贵的研究培训机会。工作重点是基于酒石酸化学模板的手性聚集体。最近发展起来的振动圆二色性（VCD）被用来探测聚集体，沿着建立的电子圆二色性（ECD）和旋光色散（ORD）。手性聚集体的三维分子结构的确定与这些工具和其他数据的方法，如电子显微镜和原子力显微镜。分子动力学模拟提供了对可能结构的进一步理解。手性光谱性质的量子化学预测和相应的实验观察的比较被用来进一步解开手性聚集体和它们的光谱性质之间的关系。这些研究有助于建立手性聚集体的结构与手性光学性质之间的关系。这项工作也有望更好地定义手性光谱方法表征手性聚集体的分析能力。

With this award, the Chemical Structure, Dynamics, and Mechanisms (CSDM-A) Program of the Division of Chemistry is funding Professor Prasad Polavarapu at Vanderbilt University to study "chiral" molecules - that is, molecules with handedness associated with them. Differences in pharmacological activity between a left-handed chiral molecule and its right-handed mirror image make it necessary to isolate these molecules from one another to investigate their properties. Dr. Polavarapu's group specifically studies chiral surfactant molecules which form special aggregate structures with encapsulation properties (used, for example, for drug delivery). They seek improved understanding of the properties of these molecules to enable better control and use. Involvement of students from both Vanderbilt and Tennessee State University through collaboration with Dr. Nsoki Phambu, is expected to provide valuable research training opportunities for undergraduates interested in the STEM disciplines.The work focuses on chiral aggregates based on tartaric acid chemical templates. Recently developed vibrational circular dichroism (VCD) is used to probe the aggregates, along with established electronic circular dichroism (ECD) and optical rotatory dispersion (ORD). Three-dimensional molecular structures of chiral aggregates are determined with these tools and additional data from methods such as electron microscopy and atomic force microscopy. Molecular dynamics simulations provide further understanding of possible structures. Quantum chemical predictions of chiroptical spectroscopic properties and comparison to corresponding experimental observations are used to further unravel the relation between chiral aggregates and their spectroscopic properties. These studies are expected to help establish the relationship between the structures of chiral aggregates and their chiroptical properties. This work is is also expected to better define the analytical capabilities of chiroptical spectroscopic methods for characterizing chiral aggregates.