Degree
Doctor of Philosophy (PhD)
Department
Chemistry
Document Type
Dissertation
Abstract
Metal-organic cages (or MOCs) are three-dimensional molecules comprised of metal nodes linked by organic ligands. While there are many types of MOCs, all possess an inner cavity allowing for confinement of guest molecules within. Confinement allows for many applications of these materials in areas including gas adsorption, separations, pollutant sequestration, biomedical applications, guest stabilization and more. Confinement within MOCs is understood to be driven by two main factors: electrostatic interactions and hydrophobic effects. Because MOCs come in many flavors, a host MOC can be chosen to best suit a target guest. This dissertation describes two main projects to observe the effects of confinement on redox-active materials. In the first project, cationic zirconium-based MOCs are synthesized and used to confine transition-metal EDTA complexes in DMSO. The effects of confinement are observed by cyclic voltammetry, where kinetic parameters are determined for the guest both within and outside MOC pores. Further, differences in host-guest interactions across different MOC structures are catalogued, and oxygen-sensitive [FeIIEDTA]2- has been stabilized to oxidation in the presence of zirconium-based MOCs. This work provides a foundation for research into the stabilization of electrocatalysts within supramolecular systems in the future by showing several effects that confinement within MOCs can have on the redox activity of guests. In the second project, an anionic aluminum-based MOC is used to encapsulate a series of manganese-based organometallic complexes structurally similar to established electrocatalysts for CO2 reduction. These complexes have been primarily studied in organic solvents but are also water-soluble. Additionally, similar complexes are known to react with one another after being electrochemically reduced, which can alter catalytic stability, activity, and selectivity. Nuclear magnetic resonance (NMR) and cyclic voltammetry are used to monitor interaction of the MOC host and guest manganese complexes. This work aids in understanding how electrocatalytic materials for CO2 reduction behave in aqueous environments, as well as the effects of interaction with MOCs on their redox activity and stability
Date
11-12-2025
Recommended Citation
Grundhoefer, John P., "Modulating Electron Transfer Properties Through Confinement in Metal Organic Cages" (2025). LSU Doctoral Dissertations. 6929.
https://repository.lsu.edu/gradschool_dissertations/6929
Committee Chair
Elgrishi, Noémie