With the support of the Organic Dynamics Program, Professor Thomas C. Pochapsky, of the Department of Chemistry at Brandeis University, is studying the structure and dynamics of closed-shell ion pairs in solution. These studies are focused on both the development of a general methodology for the characterization of dynamic self-assembling systems (i.e., multimolecular complexes in which individual components undergo rapid exchange on the NMR time scale) and the development of a more complete understanding of chemical processes which involve ion pairing. Nuclear Overhauser Effect studies probe the time-averaged structures of ion pairs and, when combined with nuclear relaxation data, provide information about motional behavior. Pulsed field gradient NMR methods allow measurement of self-diffusion coefficients for the ion pairs, allowing the determination of their aggregation state. These studies are complemented by infrared spectral analysis and by computational methods. Through a combination of experimental and computational studies, Professor Thomas C. Pochapsky, of the Department of Chemistry at Brandeis University, studies the structure and dynamics of ion pairs, molecular aggregates which display discrete interactions between positively and negatively charged species. Such ion pairs are observed under a variety of conditions in chemical and biological systems, have been implicated as intermediates in many types of reactions, and are involved in biological processes such as ion transport and molecular recognition. With the support of the Organic Dynamics Program, Professor Pochapsky is developing an in-depth understanding of the structures of ion pairs and of the dynamic processes associated with them.
