Molecular Oxidations in Homogeneous and Heterogeneous Media

有机和大分子化学计划以这一更新奖支持怀俄明州拉勒米市怀俄明大学化学系爱德华·l·克莱南博士的工作。这项工作包括详细研究单线态氧与溶液中的有机硫化合物的反应，以及与含有亚甲基蓝敏化剂的NaY沸石中的有机硫化合物和烯烃的反应。溶液研究包括对Foote反应表面的检查，氢过氧基磺酰化的分子内电子转移，它的Pummerer重排，以及单线态氧诱导1,3-二硫烷的外映反应。沸石的工作将包括实验，以探索在衬底的碳框架上正电荷积累的程度，以及沸石内氧化的机制。敏化剂，如亚甲基蓝，在光的存在下，能够将正常的三重态O2转化为激发态单重态，这对有机硫化合物和烯烃的反应性更强。这些反应的不同产物在沸石-微孔硅酸铝固体中被观察到，因为空间限制和结构内正离子的存在。这些研究有望提高我们对氧化反应机理的理解，潜在地改进合成有用化合物的方法，并为发展中的科学家提供最先进的培训。

With this renewal award the Organic and Macromolecular Chemistry Program supports the work of Dr. Edward L. Clennan in the Department of Chemistry at the University of Wyoming in Laramie, Wyoming. The work involves detailed studies of the reactions of singlet oxygen with organosulfur compounds in solution and with organosulfur compounds and olefins inside NaY zeolite containing methylene blue sensitizer. The solution studies include examinations of the Foote reaction surface, intramolecular electron transfer in the hydroperoxy sulfonium ylide, its Pummerer rearrangement, and singlet oxygen induced epimerization of 1,3-dithianes. The zeolite work will include experiments to explore the extent of positive charge buildup on the carbon framework of the substrate, and the mechanism of intrazeolite oxidation.Sensitizers, such as methylene blue, in the presence of light, are able to convert normal triplet O2 into the excited singlet state, which is much more reactive toward organosulfur compounds and olefins. Different products of these reactions are observed in zeolites - microporous aluminum silicate solids - because of steric constraints and the presence of positively charged ions inside the structure. These studies are expected to improve our mechanistic understanding of oxidation reactions, lead to potentially improved synthetic methods for making useful compounds, and provide state-of-the-art training for developing scientists.