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

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，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包含过渡金属原子的气体分子的结构和成键。一个正在研究的分子是双原子金硫化物(AuS)，它是纳米科学和分子自组装中更复杂的系统中金-硫键的模型。实验光谱的分析得到了互补计算机的辅助，目标分子的计算是与基思·库瓦塔教授和他的学生合作进行的。过渡金属化学和成键对现代科学的其他领域很重要，如化学催化、有机金属化学、纳米科学和天文学。对含金属双原子分子的研究可以为更复杂的体系中的键合提供有用的模型。该项目的重点是硫化金、硫化银、氢化钽和氧化钽分子。用能够分辨振动、转动和超精细结构的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。对光谱的分析导致了对电子态和化学键的详细表征，并提供了对其他科学家有用的准确跃迁频率。辅助计算工作使用运动方程耦合团簇方法，并提供状态能量、键长和振动频率的准确估计。这项工作的一个重要的更广泛的影响是让Macalester的学生为物理化学和化学物理的研究生工作做好准备，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.