|Organization or Institution||University of Miami|
Locking-in 1-Dimensional π-Conjugated Superstructures to Regulate the Formation of Well-Defined Nanoscale Objects
Adam Ashcraft, Chuan Liu, Kaixuan Liu, Arindam Mukhopadhyay, Tina Phan, Dalia Husainy, Jean-Hubert Olivier
University of Miami
Self-assembled architectures are fragile compositions where minor changes in temperature, solvent dielectric, and building-block concentration can trigger the dismantlement of superstructures and a concomitant loss of the emergent properties associated with them. To tackle this challenge, we are currently developing molecular strategies to lock-in 1-dimensional π-conjugated superstructures. Our goal is to create well-defined nanoscale platforms with which to unravel structure-function properties that remain elusive by current self-assembly methodologies. In this regard, we will introduce the design principles to reticulate 1-dimensional supramolecular polymers following a 1,3-dipolar cycloaddition “click-chemistry”. Confirmed by atomic force microscopy and transmission electron microscopy, organic nanomaterials created in this manner are best characterized by a nanowire morphology. These findings confirm that the conformation of supramolecular 1D assemblies can be captured using the unveiled lock-in strategy. As these well-defined nanoscale objects are soluble in aqueous media, conventional gel permeation chromatography techniques are utilized to sort them by size. Investigation of the electronic properties of length-sorted nanowires exploiting electrochemical measurement methods reveals a non-negligible stabilization of the energy of the conduction band with respect to that of parent, non-polymerized self-assembly. It is important to note that the presented strategy opens new avenues to not only capture conformation of supramolecular assemblies but also to enforce the formation of emergent electronic properties not accessible in pristine, non-covalent assemblies. Furthermore, we will show that structure-function properties of nanowires can be further modulated by modifying the molecular composition of the linker exploited to lock-in 1D superstructures.