Synthesis and Spectroscopy of New Biradicals and Related Structures

有机和高分子化学项目的资助 将支持丹尼斯·道金斯博士的研究 一组被称为双自由基的有机化学碎片。 双自由基可以被认为是含有断裂的 碳碳键 因此，他们是优秀的模型， 涉及成键的反应的过渡态和/或 断键 此外，它们不寻常的电子结构 通常导致新颖的光学和磁性。 双自由基 也作为化学反应的中间体存在。 因此他们的 化学是理解 化学结构和反应性。 本研究的主要工具是有机合成、基质 分离光谱和理论建模。 根本上 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/维斯 光谱学将用于研究电子 双自由基的结构 这种光谱学也将允许 双自由基本征反应性模式的评价 直接观察。 将使用各种理论工具 指导和解释实验研究。 具体 目标包括：一系列取代的环丁烷二基， 将首次系统研究 取代基的光谱和反应性的本地化1，3- 双自由基;一种新的设计非常高自旋有机结构; 苯和萘的非Kekule异构体和微扰 衍生物;和四面体烷的新前体。

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.