Reactive Intermediates, Reaction Mechanisms, and Catalytic Cycles in the Gas Phase

NSF化学部的化学结构、动力学和机理计划支持弗吉尼亚联邦大学化学系Scott Gronert教授的研究。格罗内特教授和他的学生正在开发和使用新的气相技术来研究催化反应，这些反应在药物和其他精细化学品的合成和生产中非常重要。他们的方法包括将质谱仪转换为气相反应器，并允许它们探测复杂反应过程中的单个步骤，目的是找到提高当前催化剂的效率和选择性的方法。Gronert教授和他的团队也在使用这项技术来寻找具有比目前使用的系统更好的性能的新催化系统。格罗内特教授的研究项目深度致力于培养各级学生，并鼓励本科生在大学生涯早期参与独立研究项目。此外，格罗内特教授每年夏天从当地的HBCU(历史上都是黑人的学院或大学)招募一名学生参与一个研究项目。现代质谱学的特殊多功能性为在高度可控的条件下研究活性中间体和探索其内在反应性提供了独特的机会。Gronert小组将离子陷阱质谱仪转化为离子反应堆，并用它们来研究气相反应动力学和平衡。这项研究的一个中心重点是分离和表征重要催化循环中的关键活性中间体。在本项目中，正在研究三个涉及连接金属络合物的系统：(1)新的基于二氮杂菲的Ir(III)C-H活化催化剂的范围；(2)在钴和镍催化的C-C偶联反应中生成潜在中间体的新的2电子还原方法；以及(3)生成异常氧化态的过渡金属并表征它们在反应过程中的作用的新的1电子还原方法。此外，变温离子反应器正被用来检测模板化的气相反应系统中的焓/熵效应。外展计划与研究紧密结合在一起，其中一个关键组成部分是每年从当地历史悠久的黑人大学弗吉尼亚联合大学招收学生。

The Chemical Structure, Dynamics and Mechanism Program of the NSF Chemistry Division supports the research of Professor Scott Gronert in the Department of Chemistry at Virginia Commonwealth University. Professor Gronert and his students are developing and using novel gas-phase techniques to study catalytic reactions that are important in the synthesis and production of pharmaceuticals and other fine chemicals. Their methodologies involve converting mass spectrometers into gas-phase reactors, and allow them to probe individual steps in complex reaction processes, with the goal of finding ways to improve the efficiency and selectivity of current catalysts. Professor Gronert and his group are also using this technology to seek out new catalytic systems that have superior properties to those currently in use. Professor Gronert's research program is deeply engaged in training students at all levels and encourages undergraduates to participate in independent research projects early in their college careers. In addition, Professor Gronert recruits one student each summer from a local HBCU (historically black college or university) to participate in a research project. The exceptional versatility of modern mass spectrometry offers unique opportunities for studying reactive intermediates under highly-controlled conditions and probing their intrinsic reactivity. The Gronert group has converted ion-trap mass spectrometers into ion reactors and uses them to study gas-phase reaction kinetics and equilibria. A central focus of the research involves isolating and characterizing key reactive intermediates in important catalytic cycles. In this project, three systems involving ligated metal complexes are being investigated: (1) The scope of new phenanthroline-based iridium(III) C-H activation catalysts; (2) New, 2-electron reduction methodologies to generate potential intermediates in cobalt- and nickel-catalyzed C-C coupling reactions; and (3) New 1-electron reduction methodologies to generate transition metals in unusual oxidation states and characterize their roles in reaction processes. In addition, a variable temperature ion reactor are being used to examine enthalpy/entropy effects in templated, gas-phase reaction systems. The outreach plan is tightly integrated into the research and a key component involves recruiting students each year from a local historically black university, Virginia Union University.