Studies of Olefin Triplets and Triplet Biradicals

烯烃三重态和三重态双自由基的研究

• 批准号: 8820268
• 负责人: Richard Caldwell
• 金额: $ 34.83万
• 依托单位: University of Texas at Dallas
• 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: 1989-01-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8820268&HistoricalAwards=false
• 关键词: Studies; Olefin; Triplets; Triplet; Biradicals

This grant in the Organic Dynamics Program supports the research of Dr. Richard Caldwell at the University of Texas at Dallas. Specifically, the structure, lifetime and energetics of photochemically-generated reaction intermediates will be explored both experimentally and by computational methods. A better understanding of the behavior and properties of transient reaction intermediates will provide a fundamental basis for their role in the outcomes of photochemical processes. Alkene triplets and triplet biradicals will be photochemically generated and studied by conventional organic mechanistic methods to determine the reaction products and infer the identity of the intermediates; by laser flash photolysis to determine transient lifetimes and intersystem crossing rates; by time-resolved photoacoustical calorimetry to determine energies of transients; and theoretically by CAS-MCSCF computations of spin-orbit coupling in small model species. The combination of these methodologies will allow a fundamental understanding of intersystem crossing as well as the energy surfaces of these intermediates. Arylalkene triplets, Norrish II and other 1,4-biradicals, triplet state di-pi-methane biradicals and some unusual trans-cyclohexenes and -cyclopentenes resulting from the alkene triplets, will be studied.

有机动力学计划的这笔赠款支持德克萨斯大学达拉斯分校理查德·考德威尔博士的研究。具体来说，光化学产生的反应中间体的结构、寿命和能量学将通过实验和计算方法进行探索。更好地了解瞬态反应中间体的行为和性质将为它们在光化学过程结果中的作用提供基础基础。 烯烃三重态和三重态双自由基将以光化学方式生成，并通过常规有机机械方法进行研究，以确定反应产物并推断中间体的身份；通过激光闪光光解来确定瞬态寿命和系间交叉率； 通过时间分辨光声量热法确定瞬态能量；理论上通过 CAS-MCSCF 计算小模型物种中的自旋轨道耦合。 这些方法的结合将使我们能够对系间穿越以及这些中间体的能量表面有一个基本的了解。 将研究芳基烯烃三重态、Norrish II 和其他 1,4-双自由基、三重态二π-甲烷双自由基以及由烯烃三重态产生的一些不寻常的反式环己烯和β-环戊烯。