Exploration of novel architectures for aromatic electronic donor-acceptor hetero-duplexes
Research within the Iverson group has been primarily focused around the investigation of aromatic donor-acceptor interactions between an electron-rich 1,5-dialkoyxnaphthalene (DAN) molecule and the electron-deficient 1,4,5,8-naphthalenetetracarboxylic diimide (NDI) species. The complementary electrostatics within this aromatic system is responsible for the powerful associative properties of these two molecules when placed in aqueous environments, leading to highly ordered, discrete face-centered modes of stacking upon complexation. The exploitation of these interactions has lead to the formation of novel molecules, called aedamers, which achieve a variety of directed folded topologies and extended hydrogel networks, oligomers which form distinct intermolecular hetero-duplex assemblies, and unique crystalline materials with novel tunable liquid crystalline properties. This dissertation describes the use of DAN-NDI aromatic donor-acceptor interactions in the design and construction of new oligomer architectures, with the aim of driving intermolecular hetero-duplex formation with higher fidelity and increased binding affinities. Chapter 2 describes efforts towards the design and construction of an amino acid based oliogmer with a highly rigidified molecular framework. A structurally rigidified scaffold would enhance the intermolecular association observed in our aromatic donor-acceptor hetero-duplexes allowing access to highly intricate and well-ordered networks in aqueous environments. Chapter 3 describes the design and synthesis of a novel DNA based architecture with the intention of creating aromatic donor-acceptor nucleoside analogs of the ubiquitous DNA building blocks. Fabrication of this novel subunit would facilitate the modular construction of larger, extended donor-acceptor oligomers enabling the formation of more expansive hetero-duplex assemblies hopefully exhibiting increased binding affinities. As a whole, these projects seek to probe the specific elements necessary for the selective intermolecular association of DAN-NDI donor-acceptor oligomers. Fine tuning of the non-covalent interactions of this class of molecules can increase the level of control we see in the directed self-assembly of these aromatic hetero-duplexes in aqueous environments. With this in hand, these systems can now potentially be utilized in a variety of applications ranging from surface immobilization techniques, to novel water-soluble polymeric materials and biologically compatible non-natural peptide based artificial proteins.