Mechanisms of Bond-Making and Bond-Breaking; Role of RadicalIons (Chemistry)

有机和高分子化学项目的资助 支持弗雷德里克格林教授的研究， 围绕反应机理的阐明。 反应 机制是键形成和键合的详细顺序， 化学变化;理解这些 过程及其控制因素是一个关键因素 来控制化学反应。 格林博士的研究 重点讨论了两种材料的成键和断裂机制 催化和非催化手段。 这项工作将追求 一种相对较新的通过“电子”引发有机反应的方法 催化作用”，也就是说：电子的添加或移除 形成高活性自由基离子。 虽然我们对反应性的基团有很多了解， 中间体称为自由基（不成对电子）和离子 （带电），目前对 自由基离子的化学，它是奇电子物种，也 携带费用。 格林小组的一个主要目标是 获得有关自由基化学性质的新信息 离子。 计划进行一项探索性研究， 自由基离子在选择的加成，环加成，逆环， 加成和重排反应。 各种电子给体 将对接受者进行评估，并注意 电化学信息和一些新的考虑 捐助者。 四元环的逆环加成反应 环状偶氮化合物（二氮杂环丁烷）构成了一个重要的测试 键断裂过程的机制的情况下。 最近的结果 为合成物质提供了有前途的途径 needed. 还计划进行实验以探讨 电子引发的二氮杂环丁烷类化合物的逆环加成反应 受体。

This grant in the Organic and Macromolecular Chemistry Program supports reserach by Prof. Frederick Greene, which is centered around the elucidation of reaction mechanisms. Reaction mechanisms are the detailed sequences of bond-making and bond- breaking which constitute chemical change; understanding these processes and their controlling factors is a critical element in controlling chemical reactivity. Dr. Greene's research will focus on the mechanisms of bond formation and rupture by both catalytic and non-catalytic means. This work will pursue a relatively new way of initiating organic reactions by "electron catalysis," that is: the addition or removal of an electron from a reactant to form a highly reactive radical ion. Although much is known about the groups of reactive intermediates known as radicals (unpaired electrons) and ions (electrically charged), much less is currently known about the chemistry of radical ions, which are odd-electron species also carrying charge. A major objective of the Greene group is to obtain new information on the chemical properties of radical ions. An exploratory study is planned to examine the role of radical ions in selected addition, cycloaddition, retrocyclo- addition, and rearrangement reactions. Various electron donors and acceptors will be evaluated, with attention to electrochemical information and to some consideration of new donors. Retrocycloaddition reactions of four-membered ring cyclic azo compounds (diazetines) constitute an important test case for mechanisms of bond-breaking processes. Recent results have provided promising routes for syntheses of substances needed. Experiments are also planned to probe the mechanism of retrocycloaddition of diazetines initiated by electron acceptors.