Department of Chemistry and Biochemistry Seminar
- Thursday, March 12, 2020 at 3:30pm
- Chemistry & Biochemistry Building, Byker - view map
Dr. Jean-Hubert Olivier from the Department of Chemistry, University of Miami will present "Expanding the Toolbox to Modulate the (Opto)electronic Properties of π-Conjugated Superstructures."
As a product of the dynamic equilibrium between solubilized building blocks and selfassembled structures, supramolecular architectures are fragile compositions where minor changes
in temperature, solvent dielectric, and building-block concentration can trigger the dismantlement of superstructures and concomitant loss of the emergent properties associated with them. Developing molecular strategies to covalently polymerize superstructures can provide entirely new nanoscale platforms with which to elucidate structure-function properties that remain elusive by current supramolecular methodologies. This lecture will introduce design principles to reticulate 1-dimensional supramolecular polymers following a 1,3-dipolar cycloaddition “click-chemistry” and the extent to which this approach can be leveraged to modulate the (opto)electronic properties of nanoscale objects. For example, we report that tethering, or “locking-in”, π-conjugated supramolecular polymers enforces the formation of robust nanoscale objects that feature a conduction band energy stabilized by more than 100 meV with respect to that of the unlocked precursors. An additional aspect of our work resides on the redox-assisted self-assembly of watersoluble, π-conjugated chromophores. We exploit this novel supramolecular tool to access out-of equilibrium intermediates through which to navigate the aggregation free energy landscapes and engineer supramolecular assemblies kinetically trapped in local energy minima. Through a combination of microscopy and spectroscopy studies, we show that the structure-function properties of kinetically trapped superstructures differ markedly with respect to those elucidated for the parent, equilibrium assemblies. Both aspects of these studies demonstrate that the ability to modulate the electronic structure of nanoscale-objects, used in conjunction with facile hierarchical organization, offers exceptional promises for the development of optoelectronic materials.
- Department of Chemistry and Biochemistry