The Role of Substrate in Accelerating the Reactivity of Graphene in Diels Alder Reactions

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program of the Division of Chemistry, Mingdi Yan and Lawrence Wolf from the University of Massachusetts-Lowell will explore the transformation of monolayer pristine graphene nanocarbon monolayer sheets in a controlled fashion through organic synthesis with a particular focus on the Diels-Alder reaction. Local hot spots of curved distorted sites will be created on the graphene surface over nano-featured substrates. Theoretical computations will be used to aid in rationally designing these graphene sheets with curved features. Pristine graphene has the potential to impact many technologically important applications, such as in display screens, nanoelectronics, solar cells, and various others and functionalized graphene has similar and yet to be discovered applications. The ability to functionalize graphene with well-defined chemical functionalities and in a controlled fashion is a frontier goal in the field and has the potential to provide access to novel materials with great potential for technological application. As part and parcel of this research project, graduate and undergraduate students will be trained in multidisciplinary research; specialized courses related to the research will also be developed. Furthermore, high school students of diverse backgrounds will be provided with summer research experience and K-12 students will be engaged through science presentations and workshop demonstrations. This project will integrate theory and experiment to provide mechanistic insights on how surface curvature enhances the reactivity of graphene and which substrate configurations best accelerate Diels-Alder and other cycloaddition reactions. In Aim 1, monolayer graphene supported on a metallic or insulating substrate having well-defined surface topography will be fabricated. Subsequently, Diels-Alder reactions will be carried out, and the extent of graphene functionalization will be determined to test the hypothesis that the reactivity of graphene will increase by introducing surface curvature and will further increase by using a metal substrate. In Aim 2, combined atomistic and larger scale computational methods, including density functional theory, semi-empirical, and molecular mechanics methods, will be developed and used to investigate the origins of the reactivity enhancement by surface curvature and the role of surface curvature and the resulting distorted electronic structure on the reactivity of graphene in cycloaddition reactions. 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.