Optical Absorption Spectroscopy of Metal Containing Molecules

这项研究是由化学部实验物理化学项目资助的。在三项相关任务中，Steimle将：a)使用瞬时调频(TFM)光谱检测和表征过渡金属二氧化物；b)通过激光诱导荧光光谱检测和表征被认为是火焰灭火催化中间体的含铁分子；以及c)执行塞曼和斯塔克光谱，以表征3D过渡金属氧化物和一氮化合物。含有金属的自由基将使用现有的激光烧蚀/超音速膨胀源或直流放电/超音速膨胀源产生。分子物种将通过分析它们的电子光谱以及光学斯塔克和塞曼光谱分裂来表征。了解过渡金属的氧化反应不仅在化学上具有重要意义，而且对表面科学和冶金等许多相关领域也是至关重要的。已发现某些含铁化合物在阻燃方面比卤素化合物有效得多，而且比卤素化合物更环保，后者的用途正在逐步淘汰。拟议的研究将为理解这些主题做出重要贡献。虽然实验和对结果的分析是复杂和复杂的，但它们有助于研究生和本科生的参与，他们在首席研究员的监督下工作。

This research is funded by the Experimental Physical Chemistry Program of the Chemistry Division. In three related tasks Steimle will: a) detect and characterize transition metal dioxides using transient frequency modulation (TFM) spectroscopy; b) detect and characterize by laser induced fluorescence spectroscopy Fe-containing molecules thought to be catalytic intermediates in flame suppression; and c) perform Zeeman and Stark spectroscopy to characterize 3d transition metal monoxides and mononitrides. The metal-containing radicals will be generated using either an existing laser ablation/supersonic expansion source or a dc-discharge/supersonic expansion source. The molecular species will be characterized through the analysis of their electronic spectra as well as of the optical Stark and Zeeman spectral splittings. Understanding the oxidation reaction of transition metals is both of fundamental importance in chemistry and is crucial to many related areas such as surface science and metallurgy. Certain Fe-containing compounds have been found to be substantially more effective at flame inhibition and are environmentally friendlier than halogen-containing compounds, whose use is being phased out. The proposed research will make important contributions to the understanding of these topics. Although the experiments and the analyses of the results are complex and sophisticated, they lend themselves to the involvement by graduate and undergraduate students who work under the supervision of the principal investigator