RUI: Electronic Spectroscopy of Gold and Silver Monosulfides and Other Transition Metal-Containing Free Radicals

在这个由化学系化学结构、动力学和机制A项目资助的项目中，Thomas D. Varberg教授和他在Macalester学院的本科生研究人员正在使用可见光和近红外光谱来研究含有过渡金属原子的气体分子的结构和键合。正在研究的一种分子是双原子硫化金（au），它是纳米科学和分子自组装中心的更复杂系统中金-硫键的模型。与Keith Kuwata教授及其学生合作，对目标分子进行了互补的计算机计算，以辅助实验光谱的分析。过渡金属化学和键合对现代科学的其他领域，如化学催化、有机金属化学、纳米科学和天文学都很重要。对含金属双原子分子的研究可以为更复杂体系中的键合提供有用的模型。该项目重点研究硫化金、硫化银、氢化钽和氧化钽分子。用高分辨率连续波激光器记录了可见光和近红外的电子光谱，该激光器能够分辨振动、旋转和超精细结构。对光谱的分析可以详细描述电子状态和化学键，并为其他科学家提供准确的跃迁频率。支持的计算工作利用运动方程耦合簇方法，提供状态能量，键长和振动频率的准确估计。这项工作的一个实质性的更广泛的影响是为马卡莱斯特的学生准备物理化学和化学物理的研究生工作，包括来自代表性不足群体的学生。此外，目标分子表现出简化的金属键，这与更复杂的纳米颗粒结构和有机反应的过渡金属催化有关。

In this project funded by the Chemical Structure, Dynamics, and Mechanisms A Program of the Division of Chemistry, Professor Thomas D. Varberg and his undergraduate student researchers at Macalester College are using visible and near-infrared spectroscopy to study the structure and bonding of gaseous molecules that contain a transition metal atom. One molecule under study is diatomic gold sulfide (AuS), which serves as a model for gold-sulfur bonding in more complex systems central to nanoscience and molecular self-assembly. The analysis of the experimental spectra are aided by complementary computer calculations on the targeted molecules are carried out in collaboration with Professor Keith Kuwata and his students. Transition metal chemistry and bonding is important to other areas of modern science, such as chemical catalysis, organometallic chemistry, nanoscience, and astronomy. Research on metal-containing diatomic molecules can serve as a useful model for bonding in more complicated systems.The project focuses on the molecules gold sulfide, silver sulfide, tantalum hydride and tantalum oxide. Electronic spectra in the visible and near-infrared are recorded with a high-resolution continuous-wave laser capable of resolving the vibrational, rotational and hyperfine structures. Analysis of the spectra leads to a detailed characterization of the electronic states and the chemical bonding, as well as providing accurate transition frequencies useful to other scientists. The supporting computational work utilizes equation-of-motion coupled-cluster methodology and provides accurate estimates of state energies, bond lengths and vibrational frequencies. A substantial broader impact of this work is to prepare Macalester students for graduate work in physical chemistry and chemical physics, including students from underrepresented groups. Furthermore, the targeted molecules exhibit simplified metal bonding that is relevant to more complex nanoparticle structures and to transition-metal catalysis of organic reactions.