Amide and Thioamide Macrocyclic Anion Receptors

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Dr. Kristin Bowman-James of the University of Kansas at Lawrence to investigate the coordination chemistry of anions using new classes of macrocyclic receptors. Specific recognition of negatively charged molecular ions, which are abundant species in the environment and biological systems, is a major challenge. This project will identify the binding patterns for a variety of anions at the molecular level and also explore the sensor capabilities of modified receptors. The ultimate objective of this project is to establish a framework for the strategic design of selective binding agents and sensors. The goal of this project is to explore the basic chemistry underlying the selective binding of anions with receptors that possess both amine and amide or amine and thioamide functionalities. The strategy is to examine systematically the influence of selected aspects of the ligand design on anion coordination: hydrogen bonding capability (amides vs. thioamides), ligand preorganization (syn or anti orientation of amide/thioamide groups), size, dimensionality (monocyclic vs. bicyclic), and charge (neutral vs. quaternized amines). Attachment of electrochemical and fluorescent probes will be used to explore the capability of these receptors as anion sensors. Substrates will include small inorganic anions, such as halides, pseudohalides and other halide-containing anions as well as oxo anions, with both trigonal and tetrahedral structures. Because of current concerns about groundwater contamination by anions such as nitrate, phosphate, and fluoride, as well as homeland security issues involving cyanide and arsenate, this study will lay the groundwork for future applications in anion sensing and removal. Both underrepresented groups and women have been involved in this research and active recruitment of underrepresented groups will continue.