Agents that selectively and efficiently extract anions (negatively charged ions) from water are potentially useful for important applications such as the removal of harmful anions from contaminated lakes and rivers, industrial and agricultural wastes, and of anions interfering with certain technological processes. Dr. Gellert Mezei of Western Michigan University conducts research to gain a better understanding of the mechanism of formation of a new class of agents for binding anions and the binding characteristics of these agents. His research aims to provide fundamental insights important for improving strategies to the design and synthesis of more efficient and selective receptors for anion extractions. In addition to training graduate students, he recruits and engages high school and undergraduate students (especially from underrepresented groups) in research. Through outreach events, such as the activities on the "Chemistry Day at the Museum" at the Kalamazoo Valley Museum, Dr. Mezei and his research group educate the general public about science and the exciting careers available through a degree in science.
This project focuses on the synthesis and study of "nanojars" that selectively encapsulate anions, such as sulfate, phosphate, arsenate and chromate. Each "nanojar" is comprised of three or four macrocyclic copper complexes ([Cu(OH)(pz)]n, where pz=pyrazolate, n=6-14) that self-assemble into a two nanometer-sized supramolecular structure with a large number of hydrogen bonds directed toward an anion inside the jar. A cation serves as a "lid" that seals the nanojar and renders the anion completely buried and inaccessible. The Macromolecular, Supramolecular and Nanochemistry Program of NSF supports Dr. Mezei's research group to investigate the mechanism of formation of these nanojars and to understand the thermodynamics of self-assembly and anion encapsulation. New nanojars with substituted pyrazole ligands are designed to enhance their selectivity for certain anions and to impart solubility in solvents of interest.
