Achiral and Chiral Nanographene Synthesis Using an Alkyne Linchpin Strategy

With the support of the Chemical Synthesis Program in the Division of Chemistry, Wesley Chalifoux of the University of Nevada, Reno is studying ways to make nanographenes from small, precise, molecular building blocks. Nanographenes are flat sheets of carbon atoms that mimic small sections of graphene. The optoelectronic properties of nanographenes make them attractive materials in applications such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and organic solar cells.

The Chalifoux research group’s efforts to develop new ways to make these molecules are supporting the design of next-generation devices. Dr. Chalifoux and his team of students are converting modifiable chemical building blocks to nanographenes under mild conditions and monitoring how specific changes in the building blocks tune the characteristics of the nanographenes, including their three-dimensional shape and optical properties.

These activities are also supporting the engagement of high school students in chemical research to encourage their engagement in science and to support their progression towards successful science, technology, engineering, and mathematics (STEM) careers.

Wesley Chalifoux and his research team are advancing the use of alkyne benzannulation as a mild and versatile strategy for preparing nanographenes with tunable optical properties. The use of high-energy alkyne-containing precursors allows for the use of mild benzannulation conditions that support expanded functional group tolerance and provide access to a variety of nanographene structures that cannot be achieved using other methods.

The Chalifoux group will apply this strategy to the synthesis of highly contorted and chiral nanographene molecular scaffolds that exhibit circularly polarized light characteristics and can be envisioned in variety of chiroptic applications such as liquid crystal displays, chiral sensing, holographic displays, three-dimensional displays, and other information technologies. The development of new C-H functionalization strategies will also be explored in combination with benzannulation to provide new and potentially facile routes to larger nanographenes that exhibit significant red shifts in the absorption and emission spectra.

These activities are synergistically providing training in organic synthesis and advanced analytical techniques for a diverse cohort of graduate, undergraduate, and high school students.

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.