Tuning the Reactivity of ortho-, meta- and para- Benzyne Analogs and Releated Polyradicals in the Gas Phase

调节邻位、间位和对位苯炔类似物及相关多自由基在气相中的反应性

• 批准号: 1152379
• 负责人: Hilkka Kenttamaa
• 金额: $ 55万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1152379&HistoricalAwards=false
• 关键词: Tuning; Reactivity; ortho; meta; para

Experimental reactivity studies on organic bi- and polyradicals are hindered by the difficulty of generating them cleanly in solution, in addition to their high reactivity and short lifetime. Information on the factors that control the chemical properties of carbon-centered sigma-type biradicals, such as the benzynes and their analogs, is highly desirable since it may allow one to "tune" their reactivity by varying structural details, and hence design bi- and polyradicals with tailored properties. This research program uses the "distonic ion approach" to study the reactivity of gaseous, carbon-centered, sigma-type mono-, bi- and triradicals via their charged analogs by using Fourier-transform ion cyclotron resonance mass spectrometers, a flowing afterglow quadrupole-octapole-quadrupole apparatus, and most recently, a linear quadrupole ion trap. These studies have demonstrated that the electron affinity and singlet-triplet gap of biradicals, as well as dehydrocarbon atom separation for meta-benzyne analogs, are among the reactivity controlling factors that can be used to "tune" the reactivity of some of these species. However, only few different ortho- and meta-benzyne analogs, and most remarkably, no para-benzyne analogs, have been studied thus far. Hence, this research will now be extended to several different and differently substituted ortho- and meta-benzyne analogs. With the means to generate para-benzyne analogs in the gas phase, an examination of their reactions is planned. Finally, the factors that control the reactivity of related tri- and tetraradicals will also be explored.The ability to predict, control and rationalize the outcomes of chemical reactions frequently requires knowledge of key reaction intermediates. Aromatic compounds that carry one (monoradicals) or more unpaired electrons (polyradicals) play an important role, for example, in organic synthesis and the biological activity of organic compounds. This research focuses on improving fundamental understanding of the chemical properties of these reactive intermediates. Ultimately, this research will lead to improved methods to synthesize new organic compounds, including drugs and new materials, as well as more rational design of new drugs. The new experimental methodologies developed here for the characterization of reaction intermediates will have an impact on experimental physical and physical organic chemistry. The broader societal impacts and enhancement of infrastructure include a large number of ethnically diverse, highly qualified science Ph.D. candidates, improved methodology for chemical analysis of organic compounds (including petroleum), and a more solid knowledge base for the design and synthesis of new organic materials and drugs.

有机双自由基和多自由基的实验反应性研究受到难以在溶液中清洁地产生它们的阻碍，除了它们的高反应性和短寿命之外。关于控制碳中心的σ型双自由基（例如苯炔及其类似物）的化学性质的因素的信息是高度期望的，因为它可以允许通过改变结构细节来“调谐”它们的反应性，并且因此设计具有定制性质的双自由基和多自由基。本研究计划使用的“distonic离子的方法”来研究气体，碳为中心的，西格玛型单，双和三自由基通过其带电的类似物的反应性，通过使用傅立叶变换离子回旋共振质谱仪，流动的余辉四极八极四极装置，最近，线性四极离子阱。这些研究已经证明，电子亲和力和单线态-三线态间隙的双自由基，以及脱烃原子分离的间苯炔类似物，是反应性控制因素，可以用来“调整”的反应性，这些物种中的一些。然而，迄今为止，仅研究了少数不同的邻-和间-苯炔类似物，并且最显著的是，没有对-苯炔类似物。因此，这项研究现在将扩展到几个不同的和不同取代的邻-和间-苯炔类似物。与手段，以产生对苯炔类似物在气相中，他们的反应的检查计划。最后，控制相关的三-和四自由基的反应性的因素也将被探索。预测，控制和合理化化学反应的结果的能力往往需要关键的反应中间体的知识。携带一个（单价自由基）或多个未配对电子（多价自由基）的芳香族化合物在有机合成和有机化合物的生物活性等方面发挥着重要作用。这项研究的重点是提高对这些活性中间体的化学性质的基本理解。最终，这项研究将改进合成新有机化合物的方法，包括药物和新材料，以及更合理的新药设计。这里开发的新的实验方法的反应中间体的表征将产生影响的实验物理和物理有机化学。更广泛的社会影响和基础设施的加强包括大量种族多样，高素质的科学博士。候选人，有机化合物（包括石油）的化学分析方法的改进，以及新有机材料和药物的设计和合成的更坚实的知识基础。