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

马奎特大学的斯科特·里德受到实验物理化学计划的支持，开展旨在回答有关卡宾和碳正离子的电子结构和光化学的关键问题的实验。这些物种是重要的活性中间体，涉及许多有机和有机金属反应、燃烧和有机小分子的热分解，以及平流层和星际化学。首先，计划应用高分辨率、状态选择的双共振技术来获得关于一些重要的卡宾物种的三重态结构、自旋-轨道混合和单重态-三重态能隙的详细信息。第二阶段将涉及对简单卤代卡宾的光物理和光化学的研究。初步研究表明，这些分子可以表现出不同寻常的光化学，这一点目前还不清楚。这些研究将寻求表征特定的卤代卡宾的光化学，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，它们长期以来一直抵制气相结构分析，尽管它们在化学上很重要。继S最近观察到的第一个卤代烃位置的气相电子光谱之后，将使用灵敏的高分辨率光谱技术来研究一系列卤代烃位置的光谱和动力学。这项研究的成果有望促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。这些项目将在各种重要技能领域为研究生和本科生提供培训。小组成员将在通过期刊出版物和在会议上发表演讲来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.