Synthesis and Spectroscopy of New Biradicals and Related Structures

新型双自由基及相关结构的合成和光谱学

• 批准号: 8701008
• 负责人: Dennis Dougherty
• 金额: $ 65.4万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-15 至 1992-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8701008&HistoricalAwards=false
• 关键词: Synthesis; Spectroscopy; New; Biradicals; Related

This grant in the Organic and Macromolecular Chemistry Program will support Dr. Dennis Dougherty's research into the properties of a group of organic chemical fragments known as biradicals. Biradicals can be thought of as molecules that contain a broken carbon-carbon bond. As such, they are excellent models for the transition states of reactions that involve bond-making and/or bond-breaking. In addition, their unusual electronic structures often lead to novel optical and magnetic properties. Biradicals also occur as intermediates in chemical reactions. Thus, their chemistry is an important part in developing an understanding of chemical structures and reactivity. The major tools of this study will be organic synthesis, matrix isolation spectroscopy and theoretical modeling. Fundamentally new structural types will be synthesized, often requiring the development of new synthesis methodologies. EPR, IR, and UV/VIS spectroscopies will be used to investigate the electronic structures of biradicals. Such spectroscopy will also allow the evaluation of the intrinsic reactivity patterns of biradicals by direct observation. A variety of theoretical tools will be used to guide and interpret the experimental studies. Specific targets include: a series of substituted cyclobutanediyls that will provide the first systematic study of the effects of substituents on the spectroscopy and reactivity of localized 1,3- biradicals; a new design for very high spin organic structures; the non-Kekule isomers of benzene and naphthalene and perturbed derivatives; and a new precursor of tetrahedrane.

有机和高分子化学项目的这笔赠款将支持 Dennis Dougherty 博士对一组称为双自由基的有机化学片段的特性的研究。 双自由基可以被认为是含有断裂的碳-碳键的分子。 因此，它们是涉及成键和/或断键反应过渡态的优秀模型。 此外，它们不寻常的电子结构通常会带来新颖的光学和磁性特性。 双自由基也作为化学反应的中间体出现。 因此，它们的化学是理解化学结构和反应性的重要组成部分。 这项研究的主要工具是有机合成、基质分离光谱和理论建模。 从根本上讲，新的结构类型将被合成，通常需要开发新的合成方法。 EPR、IR 和 UV/VIS 光谱将用于研究双自由基的电子结构。 这种光谱学还可以通过直接观察来评估双自由基的固有反应模式。 将使用各种理论工具来指导和解释实验研究。 具体目标包括：一系列取代的环丁二基，这将首次系统地研究取代基对局域 1,3-双自由基的光谱和反应性的影响；用于极高自旋有机结构的新设计； 苯和萘的非凯库勒异构体以及扰动衍生物；以及四面体的新前体。