CAS: Taming the Reactivity of Base Metal Hydrides Through Bifunctional Ligands

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Hairong Guan of the University of Cincinnati will study molecules with metal-hydrogen bonds (i.e., metal hydrides) as catalysts for the hydrogenation or reduction of fatty acid methyl esters, carbon dioxide, and sugar-derived polyols. These catalytic processes are highly desirable to the chemical industry that manufactures surfactants used in many consumer products, and converts renewable materials to fuels and value-added chemicals. This project will focus on the use of earth-abundant, inexpensive metals such as manganese, iron, cobalt, nickel, and copper to design such catalysts. To enhance the reactivity of the metal hydrides and to minimize degradation of the catalysts, ligands that not only participate in hydrogen transfer but also bind tightly to the metals will be employed. The project will contribute to the rigorous training of a diverse group of high school, undergraduate, and graduate students via a number of programs including the American Chemical Society Project SEED Program, the NSF Research Experience for Undergraduates program, and the University of Cincinnati’s Women in Science and Engineering (WISE) Program. Through this project, Professor Guan will also develop research-based materials for a laboratory course that can be used by community colleges or institutions with limited resources, provide research opportunities to underrepresented minority students, and enhance student professional development through collaborations with local chemical companies. With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Hairong Guan of the University of Cincinnati will study the strategies of improving the reactivity of base metal hydrides, which are key intermediates in many hydrogenation or reduction processes. Bifunctional and strongly chelating ligands will be designed under the hypothesis that they can deemphasize the roles played by the metals, participate in two-electron transfer, or suppress cluster formation. The specific research objectives include the development of more robust and active hydrogenation catalysts based on iron and nickel, the design of hydroxycyclopentadienyl complexes of manganese and cobalt as masked metal hydrides, and the pursuit of phosphine-ligated mononuclear copper hydrides. In support of the broader impacts of the project, Professor Guan will actively engage in programs focusing on providing research opportunities to underrepresented minority students including those from collaborating primarily undergraduate institutions. Research-based teaching materials will be disseminated more broadly in the chemical education literature and to other institutions. Active collaborations with local companies will be geared toward enhancing student problem-solving skills in an industrial setting. 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.