Chemical Triggers for Spin-State Switching: Fundamental Studies Toward Anion Receptors

Colorado State University, Fort Collins CO

Investigators

Abstract

In this project funded by the Chemical Structure, Dynamics and Mechanism Program of the Chemistry Division, Matthew Shores of Colorado State University will combine synthetic and measurement techniques to control electron spin in molecular species via non-covalent interactions. Fe(II) coordination complexes will be probed by solution methods to understand - at the microscopic level - how their spin states are influenced by outer sphere interactions with anions. These insights will inform the exploration of metal-ligand architectures where, in polar solvents, a change in complex spin state robustly signals the presence of an anionic species. Among the broader impacts of the research, diverse training in synthesis, spectroscopy, X-ray crystallography, and magnetometry will be offered; a new class of colorimetric sensors for anions of biological and/or environmental significance will be developed; and research opportunities for undergraduate students will be enhanced by close association with and support of the CSU chemistry REU program. This project intends to expand the methods by which colorless anions can be detected, by taking advantage of the propensity of certain metal complexes to switch their color and magnetic and physical properties as a result of small environmental changes. Sensing of anions under controlled, anaerobic conditions has been developed. This research aims to achieve robust sensing in water, a key goal in this field. A direct result of the research and educational activities will be manifested in the quality of training that graduate and undergraduate students obtain in the synthesis and characterization of compounds. More generally, the research will aid in developing fundamental understandings of molecular switching, and will contribute to improved imaging, data storage, and display devices.