Date of Award
Doctor of Philosophy
The research herein describes development of fundamental concepts related to new materials that are designed to be stimuli responsive materials. There are two main avenues explored in this dissertation, a synthetic exploration of a novel aromatization reaction and using single electron reduced 4,4’-bipyridine as sensors for several different inputs. The new synthetic reaction described is based off of an oxidation of a cyclohexane in order to obtain a highly functionalized aromatic ring. The particular functionality that was studied in this abstract is related to the hexaester of cyclohexane. The product of such reactions is shown to be a first generation paddlewheel dendrimer. Since the reaction is not known, mechanistic investigations were performed so that the reaction scope may be generalized for further use beyond hexaester cyclohexanes.
The second part of this dissertation shifts away from synthetic methodology into stable organic radical materials. 4,4’-bypridine shows a paramagnetic radical in its monomer form that forms diamagnetic dimers at higher concentrations. Since the dimerization is a fairly weak interaction, we enhance the degree of diamagnetism by tethering units together. Several of these units can be tethered together in a polymeric fashion. We then show the ability to disturb this diamagnetism with stimuli such as non-covalent binding interactions or the addition of heat. These changes in magnetic properties can be followed by electron paramagnetic resonance (EPR) and UV/vis spectroscopy. In addition to affecting the concentration of paramagnetic radicals by tethering units together, we also explore changing the substituents on our molecules to alter the binding constants obtained. Using the knowledge of tethering several units together, modulating our binding constants, and affecting the input by heat and non-covalent binding events, we are able to design molecules that display Boolean logic behavior and can act as sensors for a variety of inputs.
Mark James Juetten
Juetten, Mark James, "Development of Novel Organic Materials with Stimuli-Responsive Applications" (2016). Graduate Theses and Dissertations. 15733.