Gas-Phase Studies of Organic Reaction Mechanisms:

有了这个续约奖，化学结构、动力学和机制计划继续支持弗吉尼亚联邦大学的Scott Gronert教授开展的一个项目，该项目涉及使用质谱学方法研究气相中的有机反应机理。这些研究将集中在两个主要领域。首先，将考察重要的催化剂系统，目的是了解它们的作用模式并开发优化其选择性的方法。具体来说，将探索金属/卡宾体系的形成和反应活性，并将开发一种新的、通用的方法来筛选以金属为中心的Lewis酸催化剂的立体选择性。在整个项目的第二部分中，将探索控制取代反应和消除反应的速率和选择性的因素。具体来说，将确定取代基对亲核芳香取代反应的速率和产物的影响，并将表征消除反应的区域选择性和立体选择性。对于所有这些研究，中心假设是，气相反应性模式将通常平行于在溶液中观察到的模式，并提供了一种研究过程的替代方法。这项工作的基本原理是，通过气相研究，可以探索特定的孤立中间体的成键特性，从而获得在更复杂的凝聚相环境中无法从实验中获得的机理信息。这些信息在使用这些反应的应用程序的未来开发中具有很高的价值。这项研究旨在了解气相反应性模式，并表明这些模式通常与在溶液中观察到的模式平行，这项研究对于理解许多重要化学反应的机理路径具有重要意义。这些研究非常适合培训本科生研究人员，并有可能将他们招入高级学位课程。外展工作将包括前往人口比例偏低的当地学院和大学招聘，以及每年直接从弗吉尼亚联合大学(当地的HBCU)招募至少一名学生，在PI的实验室进行暑期研究体验。国际学生联合会的研究方案传统上吸引了不同的学生群体(目前有3名学生来自代表性不足的群体，5名女性)，外联努力的目的是加强该群体和系的多样性。过去，PI曾成功地将本科生纳入有意义的研究经历，并将积极招募他们进行这些研究。

With this Renewal Award, the Chemical Structure, Dynamics, and Mechanisms Program continues to support Professor Scott Gronert of Virginia Commonwealth University in a project involving investigations of organic reaction mechanisms in the gas-phase using mass spectrometric methodologies. The studies will be focused in two major areas. In the first, important catalyst systems will be examined with goals of understanding their mode of action and developing approaches for optimizing their selectivity. Specifically, the formation and reactivity of metal/carbene systems will be explored and a new, general method for screening the stereoselectivity of metal-centered, Lewis acid catalysts will be developed. In the second component of the overall project, the factors that control the rates and the selectivities of substitution and elimination reactions will be explored. Specifically, the effect of substituent groups on the rates and products of nucleophilic aromatic substitution reactions will be determined and the regioselectivity and stereoselectivity of elimination reactions will be characterized. For all of these studies, the central hypothesis is that the gas-phase reactivity patterns will generally parallel those observed in solution and offer an alternative means of investigating the processes. The rationale for this work is that by using gas-phase studies, the bonding characteristics of specific, isolated intermediates can be probed, thus, gaining mechanistic information not readily available from experiments in the more complicated condensed phase environment. This information can be highly valuable in the future development of applications employing these reactions. This research, to understand gas phase reactivity patterns and show how these will generally parallel those observed in solution, has implications for understanding the mechanistic pathways of many important chemical reactions. These studies are ideally suited for training undergraduate researchers and potentially recruiting them into advanced degree programs. Outreach efforts will include recruiting trips to local colleges and universities with large under-represented populations as well as the direct recruiting of at least one student per year from Virginia Union University (a local HBCU) for a summer research experience in the PI's lab. The PI's research program has traditionally attracted a diverse group of students (currently three from under-represented groups and five women) and outreach efforts will be aimed at enhancing diversity in the group and the department. The PI has had success incorporating undergraduates into meaningful research experiences in the past and will actively recruit them for these studies.