Studies in Organic Free Radical and Excited State Chemistry

有机自由基和激发态化学研究

• 批准号: 8820030
• 负责人: Paul Engel
• 金额: --
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-15 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8820030&HistoricalAwards=false
• 关键词: Studies; Organic; Free; Radical; Excited

This award in the Organic Dynamics Program provides support for the continuing research of Dr. Paul Engel of Rice University. The main thrust of the research is a study of the chemistry of azoalkanes and the transient intermediates formed in their thermal and photochemical decomposition. This chemistry will be approached on a broad front. Several different approaches to understanding the behavior of transient intermediates will be undertaken. The mechanism of bond-breaking in azoalkanes will be investigated by nanosecond transient absorption experiments. The effect of azoalkane structure on the cation-radicals formed by one-electron oxidation will be studied by flash photolysis of azoalkanes with electron-deficient sensitizers. Thermolysis kinetics and mass spectroscopic measurements will be used to determine the stabilization energies of a series of carbon-centered free radicals containing alpha-nitrogen functionality. Biradical lifetimes will be "clocked" by generation and rearrangement of cyclopropylcarbinyl radical centers. It is expected that these varied studies will lead to new experimental approaches to observing excited states in chemical reactions.

有机动力学项目的这一奖项为莱斯大学的保罗·恩格尔博士的继续研究提供了支持。这项研究的主要目的是研究偶氮烷烃的化学及其在热和光化学分解过程中形成的瞬时中间体。这种化学反应将在广泛的战线上进行探讨。将采用几种不同的方法来理解暂态中间体的行为。通过纳秒暂态吸收实验研究了偶氮烷键断裂的机理。偶氮烷的结构对单电子氧化形成的阳离子自由基的影响将通过偶氮烷烃在缺电子敏化剂作用下的闪光光解来研究。热分解动力学和质谱学测量将被用来确定一系列含有α-氮官能团的碳心自由基的稳定能。双自由基寿命将由环丙基卡宾自由基中心的产生和重排来“计时”。预计这些不同的研究将导致观察化学反应中激发态的新的实验方法。