Author ORCID Identifier
Document Type
Dissertation
Date of Award
2023
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Zhenqiang Z. Wang
Abstract
Anions are ubiquitous in Nature and play critical roles in both chemistry and biology. Biologically important molecules like enzymes, DNA, and ATP (adenosine triphosphate) are either anionic or contain negatively charged regions. Inorganic anions such as Cl- and HCO3- play essential roles in various physiological, environmental, and technological processes. Compared to cations, anions have larger ionic radii and more diffuse charge distribution, resulting in weaker electrostatic interactions. Developing synthetic receptors for controlled anion recognition is vital but poses significant challenges. Recent decades have shown remarkable progress in anion recognition, yielding diverse synthetic receptors with promising binding abilities. However, traditional approaches using limited functional groups often fall short in achieving desired anion binding affinity and selectivity, constraining practical applications. Metal-organic supercontainers (MOSCs) represent unique synthetic receptors promising ion recognition. Prototypal MOSCs are constructed from the assembly of divalent metal ions, carboxylate linkers, and container precursors such as sulfonylcalixarenes. The MOSCs are of particular interest owing to their diverse, tunable structures, and multi-pore architectures suitable for recognizing a wide array of guest molecules including anionic species. This dissertation addresses the challenges of anion recognition outlined above by leveraging these unique characteristics of MOSCs and expanding the functional space accessible for anion receptor design. The dissertation specifically focuses on the following key aspects: 1) Enhancing anion binding by modifying prototypal neutral MOSCs with fluorinated carboxylate linkers to create electron-deficient cavities favorably binding anions; 2) Designing new cationic MOSCs using different metal ions (i.e., Zn2+ and Ln3+), quinaldic hydroxamate (QuinHA), and pyridyl linkers, showcasing dynamic binding toward halides and pseudohalides; 3) Creating anionic MOSCs for selective anion binding by employing trivalent metal ions(i.e., Ga3+ and Ln3+), salicylhydroximate (Shi), and carboxylate linkers. Although counterintuitive, the concept of anion recognition using anionic Shi-MOSCs proves to be a viable approach to achieving selective anion binding through harnessing electrostatic repulsion as a selectivity criterion; 4) Demonstrating a practical application through HCO3- recognition by MOSCs for direct air capture (DAC) to combat global warming. This dissertation establishes MOSCs as versatile candidates for anion recognition, expanding the chemical space for receptor design and presenting potential functional applications in new frontiers.
Subject Categories
Chemistry | Inorganic Chemistry | Materials Chemistry
Keywords
METAL-ORGANIC SUPER-CONTAINERS (MOSCs), SELECTIVE ANION RECOGNITION, direct air capture (DAC), HCO3- recognition
Number of Pages
133
Publisher
University of South Dakota
Recommended Citation
Li, Hanying, "FUNCTIONALIZING METAL-ORGANIC SUPER-CONTAINERS (MOSCs) FOR SELECTIVE ANION RECOGNITION" (2023). Dissertations and Theses. 204.
https://red.library.usd.edu/diss-thesis/204