RUI: Beyond Electrostatics: Investigating the Contributions of Dispersion and Electron Transfer in Intermolecular Interactions

化学系化学结构、动力学和机制（CSDM-A）项目将通过该奖项资助阿默斯特学院的Helen O. Leung教授和Mark D. Marshall教授及其本科生研究人员，研究分子间作用力的基本性质。这项研究的最终目标是更全面地了解分子间的相互作用，它们是如何受到影响的，反过来又是如何影响分子之间的第一次相遇的。从事该项目的本科生研究人员将在一个活跃的物理化学实验室获得重要的研究经验，作为他们文科和理科教育的一部分，并有机会在科学会议上展示他们的工作。这提高了学生的科学素养，磨练了他们的思想，为他们成为未来的科学家做好了准备。通过分析傅里叶变换微波（FTMW）技术获得的旋转光谱，研究了分子间相互作用。两种类型的FTMW光谱仪（啁啾脉冲和Balle-Flygare）的可用性提供了关键的研究和教学优势，并加强了本科生对科学研究的参与。一系列气相二聚物的结构的测定，结合从头算量子化学计算，提供了有关力的性质的信息。具体来说，在质子酸和卤代乙烯之间形成的配合物揭示了分散相互作用对分子间缔合的影响。利用激光烧蚀技术制备了含金属配合物，并研究了分子间相互作用对羟基（OH）自由基电子密度的影响。

With this award, the Chemical Structure, Dynamics and Mechanisms (CSDM-A) Program of the Division of Chemistry is funding Professors Helen O. Leung and Mark D. Marshall of Amherst College and their undergraduate student researchers to investigate the fundamental nature of the forces between molecules. The ultimate goal of this research is to develop more fully the understanding of intermolecular interactions, how they are affected by, and in turn how they affect the first encounters between molecules. The undergraduate researchers working on this project receive significant research experiences in an active physical chemistry laboratory as part of a their liberal arts and sciences education and are given the opportunity to present their work at scientific conferences. This raises the scientific literacy and sharpens the thoughts of student participants, preparing them as future scientists.Intermolecular interactions are investigated through the analysis of rotational spectra obtained using Fourier transform microwave (FTMW) techniques. The availability of two types of FTMW spectrometers (chirped pulse and Balle-Flygare) provides key research and pedagogic advantages as well as enhancing undergraduate participation in scientific research. The determination of the structures of a series of gas-phase dimeric complexes, in combination with ab initio quantum chemistry calculations, provides information regarding the nature of the forces responsible. Specifically, complexes formed between protic acids and haloethylenes reveal the effects of dispersion interactions on intermolecular association. The laser ablation technique is used to generate metal containing complexes in which electron transfer is expected to play a role, and effects of intermolecular interactions on the electron density of the hydroxyl (OH) radical are studied using complexes involving this open-shell species.