Cycloparaphenylenes and Related Contorted Aromatics as Building Blocks for Multifunctional Nanomaterials

Abstract

Polycyclic aromatic hydrocarbon (PAH) ligands containing catechols (1,2-benzenediols), and their derivatives such as tetraoxolenes (1,2,4,5-benzenetetraols), have been intensely studied within coordination chemistry due to their redox non-innocence and capacity for conjugation with metal d orbitals. As such, materials containing catechol-functionalized ligands display a host of unique electronic and magnetic behavior. For example, tris(catechol)-substituted nanographenes (e.g., 2,3,6,7,10,11-hexahydroxytriphenylene) self-assemble with metal ions into extended sheets that can mimic the hexagonal structure, extended conjugation, and even metallic bandgap of graphene. However, small changes to ligand design, metal source, solvent, and other synthetic parameters can dramatically modulate the architecture of resulting materials and their properties—often in unpredictable ways. In this dissertation, I describe the use of catechol-bearing PAH ligands to build multifunctional materials across dimensionalities, and explore their emergent structure-property relationships, with a particular emphasis on [n]cycloparaphenylenes ([n]CPPs or ‘carbon nanohoops’). In doing so, I establish new chemistries that could facilitate the formation of crystalline, extended, nanotubular metal–organic, covalent–organic, and supramolecular materials.