The spectroscopy and photochemistry of key reactive intermediates: carbenes and carbocations

马奎特大学的Scott Reid在实验物理化学项目的支持下进行了一些实验，旨在回答有关碳和碳正离子的电子结构和光化学的关键问题。这些物种是重要的反应中间体，涉及许多有机和有机金属反应，小有机分子的燃烧和热分解，以及平流层和星际化学。首先，计划应用高分辨率，状态选择双共振技术来获得有关许多重要碳物种的三重态结构，自旋轨道混合和单重态-三重态间隙的详细信息。第二阶段将包括检查简单卤代烃的光物理和光化学。初步研究表明，这些分子可以表现出不寻常的光化学反应，目前还没有得到很好的理解。这些研究将寻求表征特定的卤代烃光化学，并提供关于高激发态的新信息，这些信息将作为从头计算理论的基准。第三阶段将研究碳正离子，尽管它们具有重要的化学意义，但它们长期以来一直无法进行气相结构分析。随着Reid小组最近对卤化碳离子的第一个气相电子谱的观察，一系列卤化碳离子的光谱和动力学将使用灵敏的、高分辨率的光谱技术进行研究。这项研究的成果有望推进化学和环境科学领域的知识，并作为理论化学计算的基准。这些项目将为研究生和本科生提供各种重要技能领域的培训。小组成员将通过期刊出版物和会议报告在传播研究成果方面发挥积极作用。

Scott Reid of Marquette University is supported by the Experimental Physical Chemistry Program to carry out experiments that aim to answer key questions concerning the electronic structure and photochemistry of carbenes and carbocations. These species are important reactive intermediates, implicated in many organic and organometallic reactions, in combustion and the thermal decomposition of small organic molecules, and in stratospheric and interstellar chemistry. First, plans are to apply high resolution, state-selected double resonance techniques to obtain detailed information on the triplet state structure, spin-orbit mixing, and singlet-triplet gaps in a number of significant carbene species. A second phase will involve the examination of photophysics and photochemistry of simple halocarbenes. Preliminary studies have shown that these molecules can exhibit unusual photochemistry, which at present is not well understood. These studies will seek to characterize specific halocarbene photochemistry and provide new information on higher excited states that will serve as benchmarks for ab initio theory. A third phase will examine carbocations, which have long resisted gas-phase structural analysis despite their chemical importance. Following the Reid group''s recent observation of the first gas-phase electronic spectrum of a halocarbocation, the spectroscopy and dynamics of a series of halocarbocations will be studied using sensitive, high-resolution spectroscopic techniques.Outcomes from this research are expected to advance knowledge in areas of chemistry and environmental science, and serve as benchmarks for theoretical chemistry calculations. The projects will provide training for graduate and undergraduate students in a variety of important skill areas. Group members will play an active role in disseminating research results via journal publications and presentations at conferences.