UC Berkeley

Graphene nanoribbons (GNRs) have been predicted to have exceptional traits for electronic, semiconductor, qubit, and logic applications, as well as representing a versatile platform for fundamental investigations in exotic physical phenomena. To access the remarkable electronic and magnetic properties predicted in these scaffolds, materials need to be synthesized with extreme precision. Bottom-up synthesized GNRs offer exceptional control of the resultant structure, down to the atomic level. This uniquely allows access to probe structures designed with exact molecular specifications. As the field develops and new increasingly complex scaffolds with designer attributes are envisioned, new methodologies and monomers must be designed to meet these increasing demands.Chapter 2 of this dissertation investigates the synthesis of structures that can utilize topological state engineering to influence the electronic properties of nanographenes and GNRs. This involved detailed investigations into pyrylium and xanthylium chemistry and the reactions of sterically hindered systems. Chapter 3 investigates potentially metallic GNR scaffolds for integration with easily accessible semiconducting GNRs. This work utilizes cyclization chemistry in the synthesis of cyclopentane rings, and led to the synthesis of a GNR that shows two distinct morphologies upon STM tip activation. Chapter 4 expands upon the reported synthesis of 6N-ZGNR to create new monomers that were predicted to form GNRs with novel properties. This work led to the development of a complimentary synthetic route that enables the synthesis of acridines previously inaccessible with the reported monomer synthesis. Finally, chapter 5 examines the synthesis of asymmetric N-ZGNR polymer precursors, labile solubilizing groups to facilitate MAD transfer, and 9-AGNR terminators.