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Aryloxenium Cations

芳基氧阳离子

基本信息

批准号：
2154079
负责人：
Hilkka Kenttamaa
金额：
$ 52.5万
依托单位：
Purdue University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-01 至 2025-05-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154079&HistoricalAwards=false
关键词：
Aryloxenium Cations

项目摘要

In this project supported by the Chemical Structure, Dynamics, and Mechanisms-B (CSDM-B) Program of the Chemistry Division, Professors Hilkka Kenttamaa and John Nash of Purdue University will investigate aryloxenium cations, a broad class of highly reactive compounds, whose chemistry is poorly understood. These cations are the key intermediates in many important chemical and biological reactions, such as the oxidation of phenols and alkanes, the generation of industrial thermoplastics (plastics that do not soften on heating), and the oxidative halophenol dehalogenation by dehaloperoxidase in biology. Oxenium cations have also been implicated in astrochemical studies and are thought to persist in interstellar space. Despite their importance, knowledge on their reactivity is severely limited due to difficulties in generating and studying them in solution. Therefore, although aryloxenium ions have been investigated for more than 40 years, surprisingly little is known about their fundamental chemical reactivity. The information obtained in this research will not only facilitate the rational utilization of aryloxenium cations in organic synthesis and industrial applications but will also enable the design of aryloxenium cations with tailored properties for specific applications. Educational activities in this project will include enhancing the scientific growth of graduate and undergraduate students, including students belonging to underrepresented groups, via a diverse research experience. Hence, this research helps to diversify the STEM workforce. Graduate students involved in this project will participate in industrial or government internships, which not only leads to intellectual broadening but often also to enhanced employment opportunities. These interactions are expected to lead to partnerships with industry and government laboratories, facilitating technology transfer to these laboratories.Detailed kinetic gas-phase reactivity studies on aryloxenium cations will be performed in order to improve the understanding of their chemical properties. Aryloxenium cations are novel species which contain a formally positively charged, monovalent oxygen atom with an incomplete electron shell. In spite of broad fundamental and practical interests in these compounds, relatively little is known about their reactivity. This project will utilize gas-phase ion-molecule reactions performed in ion trap mass spectrometers to explore their chemical properties. Action spectroscopy will be used to verify their structures. Aryloxenium ion reaction products with a variety of different reagents and not just solvents (not possible previously) will be identified. Rates of the reactions of aryloxenium cations will provide detailed kinetic reactivity information that is currently unavailable. The study of the influence of structural changes on the reactivity of aryloxenium cations and the examination of the reactivities of aryloxenium ions with different electronic ground states will facilitate the development of novel reactivity paradigms for aryloxenium cations. The experimental studies will be complemented by high-level quantum chemical calculations in order to deepen our understanding on the observed reactivity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

普渡大学的Hilkka Kenttamaa教授和John Nash教授将在化学部化学结构、动力学和机理- b （CSDM-B）项目的支持下研究芳基氙阳离子，这是一类广泛的高活性化合物，其化学性质尚不清楚。这些阳离子是许多重要的化学和生物反应的关键中间体，例如苯酚和烷烃的氧化，工业热塑性塑料（加热时不软化的塑料）的生成，以及生物学中脱卤过氧化物酶对卤代酚的氧化脱卤。氧鎓阳离子也与天体化学研究有关，并被认为在星际空间中持续存在。尽管它们很重要，但由于很难在溶液中生成和研究它们，关于它们的反应性的知识严重有限。因此，尽管芳基氙离子已经被研究了40多年，但令人惊讶的是，人们对它们的基本化学反应性知之甚少。本研究获得的信息不仅有助于芳基氙离子在有机合成和工业应用中的合理利用，而且可以为特定应用设计具有定制性质的芳基氙离子。该项目的教育活动将包括通过多样化的研究经验促进研究生和本科生的科学成长，包括属于代表性不足群体的学生。因此，这项研究有助于使STEM劳动力多样化。参与该项目的研究生将参加工业或政府实习，这不仅会拓宽知识范围，而且往往会增加就业机会。预计这些互动将导致与工业和政府实验室的伙伴关系，促进向这些实验室的技术转让。详细的动力学气相反应的芳炔氙离子的研究将进行，以提高其化学性质的认识。芳基氙阳离子是一种新型阳离子，它含有一个带正电的、带有不完整电子壳层的单价氧原子。尽管这些化合物具有广泛的基础和实际意义，但人们对它们的反应性知之甚少。该项目将利用离子阱质谱仪进行的气相离子分子反应来探索它们的化学性质。作用光谱学将用于验证它们的结构。芳基氙离子反应产物与各种不同的试剂，而不仅仅是溶剂（以前不可能）将被确定。芳基氙离子的反应速率将提供目前无法获得的详细的动力学反应性信息。研究结构变化对芳基氙离子反应性的影响，研究具有不同电子基态的芳基氙离子的反应性，将有助于芳基氙离子新的反应模式的发展。实验研究将辅以高水平的量子化学计算，以加深我们对所观察到的反应性的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。