RUI: Electronic Spectroscopy of Vanadium Hydride and Niobium Hydride

在化学系化学结构、动力学和机理-A（CSDM-A）项目的支持下，托马斯D.瓦尔贝格和他在麦卡莱斯特学院的本科生研究人员将使用可见光和近红外光谱来研究气相中两种过渡金属氢化物，氢化钒（VH）和氢化铌（NbH）的结构和键合。将使用激光激发和分散荧光光谱的组合来探测分子，以识别低位和激发的电子状态。光谱分析将提供分子性质的数值，如键长和振动频率。过渡金属化学和成键对现代科学的其他领域很重要，包括有机金属化学，纳米科学，化学催化和天文学。对含金属双原子分子的详细研究有助于理解这些更复杂系统中的键合。在可见光和近红外线的电子光谱将被记录与高分辨率的连续波激光能够解决的振动，旋转，和超精细结构的两个分子。光谱分配和模型拟合将导致电子状态和化学键的详细表征，并提供对其他科学家有用的准确跃迁频率。支持计算工作的合作者教授基思Kuwata和他的学生，也在Macalester学院，将利用密度泛函理论提供准确的估计基态磁偶极子和电四极超精细常数。结果也将与多组态自洽场（MCSCF）的计算由其他工人来测试这种计算方法的准确性。这项工作的一个实质性的更广泛的影响是准备Macalester学生，包括来自代表性不足的群体的学生，在物理化学和化学物理领域的研究生工作和就业。准确测定氢化钒的跃迁频率提供了额外的更广泛的影响，因为VH是我们银河系中较冷恒星或褐矮星的天文探测的良好候选者。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

WIth support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) Program of the Division of Chemistry, Professor Thomas D. Varberg and his undergraduate student researchers at Macalester College will use visible and near-infrared spectroscopy to study the structure and bonding of two transition metal hydrides, vanadium hydride (VH) and niobium hydride (NbH), in the gas phase. The molecules will be probed using a combination of laser excitation and dispersed fluorescence spectroscopy to identify low-lying and excited electronic states. Analyses of the spectra will provide values for molecular properties such as the bond length and vibrational frequency. Transition metal chemistry and bonding is important to other areas of modern science, including organometallic chemistry, nanoscience, chemical catalysis, and astronomy. Detailed studies of metal-containing diatomic molecules are useful for understanding bonding in these more complex systems. Electronic spectra in the visible and near-infrared will be recorded with a high-resolution continuous-wave laser capable of resolving the vibrational, rotational, and hyperfine structures of the two molecules. Spectral assignment and model fitting will lead to a detailed characterization of the electronic states and the chemical bonding, as well as providing accurate transition frequencies useful to other scientists. Supporting computational work by collaborator Professor Keith Kuwata and his students, also at Macalester College, will utilize density functional theory to provide accurate estimates of the ground state magnetic dipole and electric quadrupole hyperfine constants. Results will also be compared with multi-configurational self-consistent field (MCSCF) calculations by other workers to test the accuracy of this computational methodology. A substantial broader impact of this work is to prepare Macalester students, including students from underrepresented groups, for graduate work and employment in the fields of physical chemistry and chemical physics. Accurately determined transition frequencies for vanadium hydride provide an additional broader impact, as VH is a good candidate for astronomical detection in cooler stars or brown dwarfs in our Galaxy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.