Gas-Phase Studies of Organic Reaction Mechanisms:

Virginia Commonwealth University, Richmond VA

Investigators

Abstract

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.