Infrared Spectroscopy of Cation-Molecular Interactions

在这个由实验物理化学项目资助的奖项中，佐治亚大学的迈克尔·邓肯教授和他的学生将研究包含镁、钙、铝和硅的单电荷离子以及氮、二氧化碳和水等小分子的络合物。此外，邓肯和他的团队将研究多电荷金属离子和质子化分子簇的络合物。这些物质将通过脉冲激光蒸发在超音速激光束中产生，用飞行时间光谱仪进行质量选择，并用红外光解离(IRPD)光谱研究它们的结构和凝聚动力学。这些实验将探测离子与分子的相互作用，并确定大星团的结构。实验工作将与高级计算相结合，以提高我们对金属离子与小分子相互作用的理解。目前项目的一项主要工作是将红外光谱分析技术扩展到更低的能量，提供更多种类的络合物的“指纹”光谱，从结合到单个分子的离子到包含20个或更多分子的络合物。这项工作提高了我们对金属离子与小分子相互作用的了解，并将在生物化学和理解大气中金属离子的化学方面产生更广泛的影响。该项目还为实验和计算物理化学方面的研究生和博士后研究人员提供了出色的培训。

In this award, funded by the Experimental Physical Chemistry program, Professor Michael Duncan of the University of Georgia and his students will study complexes containing singly charged ions of magnesium, calcium, aluminum and silicon and small molecules such as nitrogen, carbon dioxide, and water. In addition, Duncan and his group will investigate complexes of multiply charged metal ions and protonated molecular clusters. These species will be produced in supersonic laser beams by pulsed-laser vaporization, mass-selected with a time-of-flight spectrometer, and their structures and condensation dynamics studied using infrared photodissociation (IRPD) spectroscopy. The experiments will probe ion-molecule interactions and determine the structures of large clusters. Experimental work will be combined with high-level computations to improve our understanding of the interactions between metal ions and small molecules. A major effort of the current project will be the extension of the IRPD technique to lower energies, providing "fingerprint" spectra for a wider variety of complexes, ranging from ions bound to a single molecule to complexes containing twenty or more molecules.This work improves our knowledge of the interactions between metal ions and small molecules and will have a broader impact in biochemistry and in understanding the chemistry of metals ions in the atmosphere. The project also provides excellent training for graduate and postdoctoral researchers in experimental and computational physical chemistry.