Sigma Pi Interactions in Hydrocarbon Cation Radicals and SS Bonds

在有机动力学计划的支持下，Nelsen博士将研究烯烃阳离子自由基与氧反应的详细机理，他还将研究含有硫-硫键的化合物中的电子相互作用。在这个项目的第一部分，Nelsen博士将研究伴随着某些烷基化烯和双烯与基态氧反应的碳骨架重排。这些骨架重排导致一些烯烃产生五元环过氧化氢，与四元环竞争。在第二部分中，我们将进行实验和理论研究，旨在探索电子效应对含有S-S键的化合物中转动势垒的影响。%一组特别吸引人的过氧化物族，称为“二氧杂环烷”，由两个碳和两个氧以四元环连接在一起。Nelsen博士开发了一种新的反应类型，在该反应中，基态氧和烯烃通过中间阳离子自由基直接生成二恶烷。他的方法允许合成新的二恶烷，这是其他更传统的制备二恶烷的方法所不能做到的。在这个项目的第一部分，尼尔森博士将研究这一过程的详细机制。在第二部分，将进行实验，旨在阐明含有硫-硫键(S-S)键的化合物中的电子相互作用影响其化学的机制。由于S-S键的强度在生物系统中有重要的影响，尼尔森博士整体研究的这一方面的结果可能会对药物设计产生影响(除了它们对物理-有机化学和理论化学的基本重要性之外)。

With support from the Organic Dynamics Program, Dr. Nelsen will study the detailed mechanism of the reaction of alkene cation radicals with oxygen, and he will also investigate electronic interactions in compounds that contain sulfur-sulfur bonds. In the first part of this project, Dr. Nelsen will study carbon skeletal rearrangements that accompany the reaction of certain alkylated alkenes and dienes with ground state oxygen. These skeletal rearrangements cause some alkenes to produce five-membered ring peroxides in competition with four-membered rings. In the second part, experimental and theoretical studies will be performed that are designed to probe the influence of electronic effects on rotational barriers in compounds that contain S-S bonds. %%% A particularly fascinating group of peroxides, called "dioxetanes", have two carbons and two oxygens linked together in a four-membered ring. Dr. Nelsen has developed a new type of reaction in which dioxetanes are produced directly from ground-state oxygen and alkenes via an intermediate cation radical. His approach permits the synthesis of new dioxetanes that cannot be made by other, more traditional methods for preparing dioxetanes. In the first part of this project, Dr. Nelsen will study the detailed mechanism of this process. In the second part, experiments will be performed that are designed to clarify the mechanism by which electronic interactions in compounds that contain sulfur-sulfur (S-S) bonds affect their chemistry. Since the strength of the S-S bond has important consequences in biological systems, the results of this aspect of Dr. Nelsen's overall study may have impact upon drug design (in addition to their fundamental importance to physical-organic and theoretical chemistry).