RII Track 4: Electronic Structure Calculations to Characterize Mechanisms of Regioselective Additions to Olefins and to Advance P-31 NMR as a Reporter of Catalytic Intermediates

Wichita State University, Wichita KS

Investigators

Abstract

Non-technical Description Chemical reactions between metals and organic compounds may be complex and it is common for there to be numerous steps in a reaction process. A better understanding of the mechanisms and potential molecular structures involved in these reactions is needed both to optimize processes and to predict the molecular structures that can result from these industrially important reactions. The PI will conduct research at the University of Illinois Urbana-Champaign (UIUC), where she and her collaborators will focus on reactions such as those used for the synthesis of drug candidates and pharmaceuticals. The resources available at the National Center for Supercomputing Applications at UIUC will be used to conduct work grounded in the PI's computational chemistry background. The availabilities of the computing power and advanced instruments for chemical analysis at UIUC will be of great value in unraveling the reaction mechanisms under study. In addition to having access to these facilities, the PI and her students from Wichita State University will form a close collaboration with an active research group at UIUC, thereby strengthening the partnership between the institutions. Technical Description The fellowship will support the PI's activities at UIUC to computationally characterize regioselective additions to olefins, catalyzed by rhodium and iridium phosphine complexes. Synergistic computation-experiments will develop a framework to guide synthetic advances. Electronic structure calculations will be used to acquire relative energies and geometries of organometallic complexes, catalytic intermediates, IR and NMR spectra associated with intermediates, and transition state energies, to thereby elucidate the origins of selectivity in catalyzed reactions and guide the design of future syntheses. The project will also include an assessment of the computational methods available for calculation of organometallic 31P NMR chemical shifts and 1JRh-P coupling. Once reliable methods are identified, computationally-assisted assignment of 31P NMR spectra could be transformational in mechanistic studies, allowing for routine characterization and tracking of catalytic intermediates. On-site work will take advantage of the UIUC NMR facility to acquire spectra. The results of electronic structure calculations by the PI will be coupled with experiments to enable advancements in synthesis, through characterization of reaction mechanisms for recently discovered catalytic processes, and by predicting outcomes of modified catalysts and substrates. Results will expand the scope of chemical reactions to new substrates or products, particularly for drug development and manufacture, and facilitate development of greener chemical processes.