RUI-Antiaromaticity of Indenylidene Dications and the Aromaticity/Antiaromaticity Continuum

RUI-茚亚基双阳离子的反芳香性和芳香性/反芳香性连续体

• 批准号: 0242227
• 负责人: Nancy Mills
• 金额: $ 25.3万
• 依托单位: Trinity University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0242227&HistoricalAwards=false
• 关键词: RUI; Antiaromaticity; Indenylidene; Dications; Aromaticity

The concepts of aromaticity and antiaromaticity play central roles in organic chemistry. Although somewhat elusive concepts, a combination of experimental and calculational tools may be used to assess aromacity and antiaromaticity through analysis of magnetic, structural, and energetic criteria. Indenylidene dications allow the assessment of magnetic properties through the paratropicity of protons on both the five- and six-membered rings, allowing evaluation of the antiaromaticity suggested by the nucleus independent chemical shift values. Because the cyclopentadienyl ring of the indenylidene cation can respond to increased antiaromaticity through deformation, structural properties can be assessed. Energetic properties can be assessed by electrochemical oxidation and comparison of redox potentials with those of non-antiaromatic model systems. By playing the various criteria against each other in aromatic and antiaromatic systems, the criteria that most effectively define aromatic/antiaromatic systems will be exposed.Ever since the initial realization that benzene and related "aromatic" hydrocarbons display unusually high stability, the factors responsible for this stability have been of great interest. "Aromaticity" and its counterpoint, antiaromaticity, in which compounds display lower than anticipated stability, play central roles in defining organic chemical structure and reactivity. With the support of a Research at Undergraduate Institutions (RUI) grant from the Organic and Macromolecular Chemistry Program, Professor Nancy S. Mills, of the Department of Chemistry at Trinity University, is exploring new molecular systems expected to display antiaromaticity. Through the rational design and synthesis of appropriate organic molecules and analysis of their magnetic, structural, and energetic properties, Professor Mills is defining the criteria that most effectively define aromaticity and antiaromaticity. A large number of undergraduate research assistants will participate in these studies, providing them with valuable research experience and education in a variety of experimental, instrumental, and theoretical techniques.

芳香性和抗虫性的概念在有机化学中起着核心作用。尽管有点难以捉摸的概念，但通过分析磁，结构和能量标准，可以使用实验和计算工具的组合来评估芳香和反脉络膜。甘油烯基允许通过质子在五元和六元环上的质子的副核度评估磁性，从而评估了原子核独立化学移位值所建议的抗乳节性。由于甘苯基阳离子的环戊二烯基环可以通过变形响应抗乳头上的增加，因此可以评估结构特性。可以通过电化学氧化和氧化还原电势与非安装模型系统的电势进行比较来评估能量性能。通过在芳香和抗虫系统中互相遵守各种标准，将暴露出最有效定义芳族/抗脉络膜系统的标准。由于最初意识到苯和相关的“芳族”碳氢化合物表现出异常高的稳定性，因此导致这种稳定性的因素非常兴趣。 “芳香性”及其对立点，即化合物的表现低于预期的稳定性，在定义有机化学结构和反应性方面起着核心作用。在有机和大​​分子化学计划的本科机构（RUI）赠款的一项研究的支持下，Trinity大学化学系的Nancy S. Mills教授正在探索预期表现出抗气质性的新分子系统。通过合理的有机分子的合理设计和综合及其磁性，结构和能量特性的分析，米尔斯教授定义了最有效地定义芳香性和抗树脂性的标准。大量的本科研究助理将参与这些研究，为他们提供各种实验，工具和理论技术的宝贵研究经验和教育。