Organic Free Radical Chemistry

有机动力学计划的这笔赠款支持 马丁·E教授的工作。韦恩州立大学的纽科姆 大学 许多非常快速的有机自由基反应将 包括二级自由基捕获反应， 接近在低粘度溶剂中的扩散速率， 高活性自由基的有序重排， 在室温下的寿命短至几皮秒。 一个 间接动力学法测定碳- 据报道，中心的激进重排将是 进一步发展，使其具有最终的动能， 分辨率在室温下约一皮秒，将是 即使在不可能进行直接动力学研究的情况下也是有用的。 的 将间接法推广到酰氧基的脱羧反应 自由基和氮中心自由基的反应。 快速 芳基取代的环丙基-原基的重排， 取代的5-己烯基和立方基原基将 要充分定性。 自由基重排的应用 含铁酶及其模型的机理研究 将被启动。 直接激光闪光动力学方法也将 也可用于研究酰氧基自由基的脱羧反应 作为以碳和氮为中心的自由基的重排。 %%% 有机自由基，带有奇数个电子的中性物质， 将被研究。 这些活性物质将由以下物质产生： 稳定前体分子的热稳定性。 的间接方法 确定自由基的反应速率将是 开发 这种新的速率测量方法将允许 含碳和含氮反应的检验 自由基，以前太快，研究方便。 应用该新技术检测含铁量 酶及其模型将被启动。 结果 希望提供有价值的信息，可以在广泛的 涉及自由基的各种有机和生物反应 中间体的

This grant from the Organic Dynamics Program supports the continuing work of Professor Martin E. Newcomb at Wayne State University. A number of very fast organic radical reactions will be studied including second order radical trapping reactions that approach the rate of diffusion in low viscosity solvents and first order rearrangements of highly reactive radicals that have lifetimes at room temperature as short as several picoseconds. An indirect kinetic method for determining rate constants of carbon- centered radical rearrangements which has been reported will be further developed such that it will have an ultimate kinetic resolution at room temperature of about one picosecond and will be useful even when direct kinetic studies are not possible. The indirect method will be extended to decarboxylations of acyloxy radicals and reactions of nitrogen-centered radicals. Fast rearrangements of aryl-substituted cyclopropyl-carbinyl radicals, substituted 5-hexenyl radicals and the cubylcarbinyl radical will be fully characterized. Applications of radical rearrangements in mechanistic studies of iron-containing enzymes and their models will be initiated. A direct laser-flash kinetic method will also be utilized to study decarboxylations of acyloxy radicals as well as rearrangements of carbon- and nitrogen-centered radicals. %%% Organic radicals, neutral species with an odd number of electrons, will be studied. These reactive species will be generated by thermolysis of stable precursor molecules. An indirect method of determining the rates of reactions of the radicals will be developed. This new rate measurement method will allow examinations of reactions of carbon and nitrogen containing radicals which were previously too rapid to study conveniently. Application of this new technology to examine iron-containing enzymes and their models will be initiated. The results are expected to provide valuable information that can be used in a wide variety of organic and biological reactions that involve radical intermediates.