Hydrogen Bonding, Proton Transfer, and Clusters on the Brink of Chemical Change

在这项由化学系化学结构、动力学和机制计划资助的项目中，明尼苏达大学的肯尼斯·R·利奥波德教授对分子之间的引力进行了基础研究。这些力在自然界中无处不在，它们的研究奠定了我们对各种化学现象的理解的基础。这项工作是通过创建由两到三个分子组成的小团簇并研究它们的物理性质来完成的。通过一次只将几个分子组合在一起，就实现了充分理解引力所需的简化。这项工作确定了提供最有用的基本信息的原型系统。只要有可能，就会选择含有已知或怀疑在地球大气中活跃的分子的原型，从而为大气科学提供基础知识。对大气重要问题的直接关注产生了合理评估自然和人为变化对环境的影响所需的基本信息。对致力于这些问题的学生和博士后研究员的教育也产生了额外的影响。这个项目继续扩大主要是本科生机构(PUI)的更广泛的合作者群体。能够在短时间内收集数据，有利于让本科生有机会从头到尾看到一个项目。利用超音速射流中的微波光谱测定了小分子弱结合络合物的分子结构和电子结构。研究包括含有三氧化硫、羧酸、硫酸和/或胺的络合物。特别强调的是处于化学反应边缘的系统。例如，质子转移是一个共同的主题，它的研究提供了一个关于溶剂化在促进化学变化中的作用的一瞥。当观察到量子力学隧道效应时，它提供了挑战理论化学动力学的实验基准。探索了三维打印作为一种方便和廉价的方法来优化用于产生感兴趣的化学物种的超音速喷嘴的设计。这项工作更广泛的影响部分在于它阐明了支配溶剂化和决定物质性质的基本相互作用。所获得的理解为分子生物学和环境科学等不同领域提供了信息。其他影响来自它提供的对研究生、本科生和博士后的培训。

In this project funded by the Chemical Structure, Dynamics, and Mechanisms A Program of the Chemistry Division, Professor Kenneth R. Leopold at the University of Minnesota performs fundamental studies on the forces of attraction between molecules. These forces are ubiquitous in nature and their study underlies our understanding a wide variety of chemical phenomena. The work is done by creating small clusters of two or three molecules and studying their physical properties. By grouping only a few molecules at a time, the simplification needed to fully understand the attractive forces is achieved. This work identifies prototypical systems that provide the most useful basic information. Whenever possible, prototypes are chosen that contain molecules known or suspected of being active in the Earth's atmosphere, thus providing foundational knowledge for atmospheric science. The direct focus on atmospherically important problems produces basic information needed to rationally evaluate the impact of both natural and anthropogenic changes to the environment. Additional impact is realized in the education of students and postdoctoral fellows who work on these problems. This project continues to grow a broader set of collaborators at Primarily Undergraduate Institutions (PUIs). The ability to collect a data in a short time is conducive to allowing undergraduate students the opportunity to see a project through from beginning to end. Microwave spectroscopy in a supersonic jet is used to determine molecular and electronic structure in small weakly bound complexes. Studies include complexes containing sulfur trioxide, carboxylic acids, sulfuric acid, and/or amines. Special emphasis is placed on systems that are on the brink of chemical reaction. Proton transfer, for example, is one common theme and its study provides a glimpse of the role of solvation in promoting chemical change. Quantum mechanical tunneling, when observed, offers experimental benchmarks with which to challenge theoretical chemical dynamics. Three-dimentional printing is explored as a convenient and inexpensive means of optimizing the design of the supersonic nozzles used to generate the chemical species of interest. The broader impact of this work lies, in part, in its elucidation of the fundamental interactions that govern solvation and determine the properties of matter. The understanding obtained informs fields as diverse as molecular biology and environmental science. Additional impact is derived from the training of graduate, undergraduate, and postdoctoral students that it provides.