Organic Free Radical Chemistry

有了这个续期奖，有机和高分子化学项目继续支持马丁·E·纽科姆博士在韦恩州立大学化学系的工作。这项工作的主要重点是了解有机合成和生物系统中涉及的自由基反应的机理细节。自由基是非常活跃的奇电子物种，是许多化学反应的中间体，可能只持续几纳秒或皮秒(亿亿分之一秒或万亿秒)。这些自由基是由持续时间很短的激光闪光产生的。获得的机理信息对合成有机化学家和对DNA裂解感兴趣的生物化学家很有价值，DNA裂解涉及几种抗癌剂影响的自由基反应。在工作过程中，Newcomb博士正在为本科生、研究生和博士后提供出色的培训，其中有几位是西班牙裔或非裔美国人。Newcomb博士的大部分研究涉及通过激光闪光光解产生的碳或其他以原子为中心的自由基，这些自由基是为研究提供所需的自由基的前体。特别令人感兴趣的是紫外线吸收自由基，它们的单分子环化反应可以实时测量--提供‘自由基时钟’，然后可以通过竞争实验和产品分析来测量其他不能吸收紫外线的自由基的反应速率。除了延长他的自由基时钟工作，纽科姆博士还计划扩大他的研究范围，包括刘易斯酸催化、β-酯基反应和有机金属反应。

With this renewal award the Organic and Macromolecular Chemistry Program continues to support the work of Dr. Martin E. Newcomb in the Department of Chemistry at Wayne State University. The major focus of the work is to understand the mechanistic details of radical reactions that are involved in organic synthesis and in biological systems. Radicals are very reactive odd-electron species which are intermediates in many chemical reactions, and which may last only for nano or picoseconds (billioniths or trillioniths of a second). The radicals are generated by a very short duration laser flash. The mechanistic information obtained is valuable to synthetic organic chemists, and to biochemists interested in the DNA cleavage, involving radical reactions, effected by several anti-cancer agents. In the course of the work Dr. Newcomb is providing excellent training for undergraduate, graduate, and postdoctoral students, several of whom are hispanic or Afro-American.Much of Dr. Newcomb's research involves carbon- or other atom-centered radicals generated by laser flash photolysis, from precursors made to provide the desired radicals for study. Of particular interest are uv absorbing radicals whose unimolecular cyclization reactions can be measured in real time - providing 'radical clocks' which can then be used to measure, through competition experiments and product analyses, rates of reaction of other radicals which are not uv absorbing. In addition to extending his radical clock work, Dr. Newcomb plans to extend his studies to include Lewis acid catalysis, reactions of beta-ester radicals, and organometallic reactions.