Organic Free Radical Chemistry

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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.