Date of Award

Spring 2020

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

First Advisor

Natalia B. Shustova

Abstract

Metal-organic frameworks (MOFs), which are well-defined and porous extended structures consisting of organic linkers connected to inorganic secondary building units, are a class of materials that have received tremendous attention over the last decade. This geometrically growing interest in MOFs is attributed to their properties of porosity, tunability, modularity, crystallinity, flexibility, and long-term stability, which makes them attractive candidates for various applications. This dissertation focuses on two major studies, the first part encompasses the strategic design, preparation, and extensive studies of actinide containing MOFs (An-MOFs). This work, presented within the first two chapters, demonstrates the effective utilization of MOF modularity and versatility for radionuclide incorporation and sequestration. The highlights of the performed research include: (i) the synthesis of the first examples of actinide-based MOFs with unsaturated metal nodes necessary for the incorporation of a high actinide content within the MOF, (ii) thermodynamic studies of profoundly water-stable An-MOFs, (iii) “structural memory” effect of An-MOFs upon solvent exposure, and (iii) electronic structure studies of heterometallic multinuclear An-MOFs, prepared via metal node engineering. The fundamental knowledge gained from these studies is aimed towards developing novel waste forms for more effective nuclear waste management. The second part which is presented in the last two chapters, reveal investigative studies of the effect of the incorporation of a second metal on the electronic structure and catalytic proficiency of three distinct classes of heterometallic multinuclear MOFs. Utilizing the metal node vi engineering technique, we are able to preserve MOF porosity while tuning framework electronic structure and catalytic activity. Combination of experimental and theoretical studies of the heterometallic MOFs, for example, single crystal and powder X-ray diffraction, X-ray photoelectron spectroscopy and theoretical modeling, allowed us not just to establish the structure-property relationship of these systems, but also provide valuable insights into the improvement and expansion of MOF applications.

Rights

© 2020, Otega Anthonia Ejegbavwo

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