Spectroscopic Studies of Partially Bound Lewis Acid-Base Complexes

实验物理化学项目支持明尼苏达大学双子城校区的Ken Leopold对Lewis酸碱络合物的结构和电子性质进行傅立叶变换微波(FTMW)光谱研究。在这些研究中，他将专注于给体-受体键仅部分形成的络合物，即介于范德华和化学相互作用之间的成键机制。在以前的工作中，利奥波德教授观察到，处于范德华和化学键之间的中间区域的气相物种在结晶时结构发生了巨大的变化。在这些研究中，他将(1)将这项工作扩展到更多的络合物，以研究Lewis酸碱度对给体-受体键性质的影响，(2)测量部分键合分子的偶极矩，以及(3)表征包含部分键合单元的较大团簇。部分键合物种在各种化学领域中都很重要。部分结合体系最有趣的方面之一是它们对周围介质的超敏性。当将气相物种与其晶体类似物进行比较时，这种现象最为明显。这些研究将为旨在进一步了解电子对供体-受体键性质的越来越多的理论工作提供实验上的补充。

The Experimental Physical Chemistry Program supports Ken Leopold of the University of Minnesota-Twin Cities Campus in his Fourier-transform microwave (FTMW) spectroscopic studies of the structural and electronic properties of Lewis acid-base complexes. In these studies, he will focus on complexes in which the donor-acceptor bond is only partially formed, i.e., a bonding regime intermediate between van der Waals and chemical interactions. In previous work, Prof. Leopold observed that gas phase species which lie in the intermediate regime between van der Waals and chemical bonding undergo enormous changes in structure upon crystallization. In these studies, he will (1) extend this work to a wider number of complexes to investigate the effects of Lewis acidity and basicity on the nature of the donor-acceptor bond, (2) measure dipole moments of partially bonded molecules, and (3) characterize larger clusters containing a partially bonded unit. Partially bonded species are important in a variety of areas of chemistry. One of the most interesting aspects of partially bound systems is their hypersensitivity to a surrounding medium. The phenomenon is most apparent when comparing gas phase species with their crystalline analogues. These studies will provide an experimentally grounded complement for a growing body of theoretical work aimed at further understanding the nature of the electron pair donor-acceptor bond.