Solid-state NMR studies of inorganic and bioinorganic materials

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Our research program employs nuclear magnetic resonance (NMR) spectroscopy to study and understand the structure and properties of solid materials. NMR relies on the same principle as magnetic resonance imaging (MRI): at the hearts of atoms lie tiny magnets ('nuclear spins') which, when placed in a large external magnetic field, respond to radiofrequency pulses. By observing how the nuclear spins behave under this situation, we can learn a great deal about the molecular and electronic structure surrounding the atom. We are specifically looking at atoms in unique bonding environments in inorganic and bioinorganic solids. In Ottawa we are fortunate to have access to a world-leading 900 MHz solid-state NMR spectrometer. This spectrometer allows us to analyze traditionally "difficult" elements such as chlorine. We are pursuing the development and application of chlorine NMR spectroscopy of solids in order to improve our fundamental understanding of NMR interactions. There are also several practical applications of chlorine solid-state NMR which we are pursuing. For example, we are interested in being able to characterize the chloride ion binding environments in large membrane protein ion channels. To be able to do this, we need to start by examining smaller peptide hydrochloride systems. Another application is in the study of hydrogen storage materials like magnesium chloride-ammonia complexes. We intend to apply chlorine, magnesium, nitrogen, and hydrogen NMR spectroscopy to observe and better understand the absorption and desorption of ammonia in this and related inorganic systems. Another aspect of our research program entails the characterization of heavy metal-heavy metal interactions (e.g., silver-silver interactions) in order to better understand how NMR spectroscopy can be used to probe for these interactions in new materials of unknown structure. We employ quantum chemical calculations of the NMR parameters we measure in order to corroborate our experimental findings, and improve our overall understanding of the structural factors which influence the NMR observables.