Organic Free Radical Chemistry

有了这个更新奖的有机和高分子化学计划继续支持博士马丁E。纽科姆在韦恩州立大学化学系。 工作的主要重点是了解参与有机合成和生物系统的自由基反应的机理细节。 自由基是非常活泼的奇电子物种，是许多化学反应的中间体，并且可能仅持续纳秒或皮秒（十亿分之一秒或万亿分之一秒）。 自由基是由非常短的激光闪光产生的。 所获得的机械信息是有价值的合成有机化学家，并感兴趣的DNA裂解，涉及自由基反应，由几种抗癌剂的生物化学家。 在工作过程中，纽科姆博士为本科生、研究生和博士后学生提供了出色的培训，其中有几个是西班牙裔或非洲裔美国人。纽科姆博士的大部分研究都涉及激光闪光光解产生的碳或其他原子中心的自由基，这些自由基来自为研究提供所需自由基的前体。 特别令人感兴趣的是紫外吸收自由基，其单分子环化反应可以在真实的时间内测量-提供“自由基钟”，其然后可以用于通过竞争实验和产物分析来测量不吸收紫外线的其他自由基的反应速率。 除了扩展他的自由基时钟工作，纽科姆博士计划扩展他的研究，包括刘易斯酸催化，β-酯自由基的反应，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.