CAS: Weakly Coordinating Cations and Charge-Activated Catalysts

With the support of the Chemical Structure, Dynamics and Mechanism-B and Chemical Catalysis Programs in the Division of Chemistry, Professor Steven Kass of the Department of Chemistry at the University of Minnesota is developing new classes of positively charged ions that only weakly interact with negatively charged ions. The goal of this research is to create practical, useful, and environmentally friendly catalysts and chemical reagents by breaking the paradigm that opposites attract. Since this project spans a broad range of chemical disciplines, it is well suited for training and educating young scientists. An NSF-Research Experiences for Undergraduates grant enhances the broader impact of this work. Weakly coordinating anions are well developed and extremely useful in many areas of chemistry from the analysis of blood via ion selective electrodes to the preparation and characterization of novel electrophilic compounds. Their oppositely charged counterparts, weakly coordinating cations, are also of great importance (e.g., anionic polymerizations, ionic liquids, battery electrolytes) but are underdeveloped and ripe for further exploration. The focus of this three-year award is to develop new and more weakly interacting cations which will result in more reactive nucleophiles and bases (aim 1). It will also enable the investigation of charge-enhanced bases and nucleophiles with greater reactivities than their noncharged counterparts (aim 2). Bifunctional charge-activated metallocenium ions with Lewis and BrØnsted acidic sites will be studied as well (aim 3). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.