Cationic Lewis acids as anion receptors

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

Dr. François Gabbaï, Chemistry Department, Texas A&M University, is supported by the Chemical Structure, Dynamics and Mechanisms Program to explore novel, cationic, main group Lewis acids as receptors for small anions including fluoride, cyanide and azide. This research focuses on the synthesis and study of boron, silicon and antimony compounds whose anion affinity is increased by a combination of Coulombic, hydrophobic, and/or chelate effects. These new, cationic Lewis acids are studied as acceptors in charge transfer processes. This reactivity can be harnessed for the design of turn-on anion sensors. In addition to investigating the synthesis and structure of these novel main group compounds, special attention is devoted to their anion binding selectivity, their compatibility with aqueous environments, and the magnitude of the photophysical response induced by anion binding. This research advances the fundamental understanding of anion recognition processes. Cyanide is widely available in both research and industrial settings even though its potential release into the environment is a source of concern; Cyanide is a toxic anion which can bind to and deactivate enzymes in the body, sometimes with fatal consequences. While fluoride is often added to drinking water and toothpaste because of its beneficial effects in dental health, high doses of this anion can be lead to dental fluorosis. Anion receptors capable of binding and/or sensing potentially toxic anions in water aid in both environmental remediation and medicine. The graduate and undergraduate students involved in this research program receive excellent training and research experiences in synthetic inorganic chemistry and photophysics. By being exposed to a project concerning the capture of toxic anions in water, this project increases the students' awareness of current environmental and health challenges. Efforts to translate some of this research into undergraduate Inorganic Chemistry Laboratory courses provide a vector for the integration of research and undergraduate education.