Bernal Institute Research Forum

Date: 9th July 2018 to 11th July 2018
Time: 11:00 to 12:00
Duration: Talks, each one-hour in duration, will be given on 9, 10 & 11 July commencing at 11:00am each day.
Location: MSG-025 MSSI Building Extension

Professor Roderick E. Wasylishen, University of Alberta, Canada.

NMR Spectroscopy of Solid Materials.

Monday, 9 July – Introduction to NMR Studies of Solids and Several Applications Involving Spin-½ Nuclei.

The fundamental interactions responsible for the appearance of a NMR spectrum will be briefly reviewed. Techniques to characterize the magnetic shielding and spin-spin coupling tensors will be discussed and illustrated. Several applications of high-resolution NMR spectroscopy in studying spin-½ nuclei in solids will be presented. For example, hydrogen bonding in the enol-isomers of 1,3-diketones (e.g., dibenzoylmethane, curcumin), polymorphism, the origin of unusual chemical shifts in transition metal hydrides, etc.

Tuesday, 10 July – Advantages of Using High Magnetic Field Strengths Focusing on Quadrupolar Nuclei.

Approximately two-thirds of all NMR-active nuclei are quadrupolar nuclei, I > 1/2, with non-integer spin (e.g., isotopes we have studied include 11B, 23Na, 35/37Cl, 63/65Cu, 69/71Ga, 75As, 99Ru with I = 3/2; 17O, 27Al, 55Mn, 101Ru, 105Pd, 121Sb with I = 5/2; 51V, 59Co, 133Cs, 139La with I = 7/2; 97Sr, and 113/115In with I =9/2). The essential theory necessary for understanding NMR spectra of quadrupolar nuclei will be reviewed and several examples from our lab will be presented. The benefits of using high-magnetic field strengths for NMR studies of non-integer quadrupolar nuclei will be discussed.

Wednesday, 11 July:

i) Probing Dynamics in Solids Using NMR Line Shapes & Relaxation Rates. Several examples illustrating how NMR line shapes and relaxation data can provide information on dynamics of molecules in orientationally disordered solids (e.g., adamantane, cubane, etc.) will be presented. As well, the dynamics of the methylammonium cation in methylammonium lead halide perovskites will be discussed in detail. These materials have attracted enormous attention from the scientific community because of their high efficiency photovoltaic properties.

ii.) The Future of SSNMR in Materials Science. It is apparent that the number of applications of NMR spectroscopy in studying solid materials is going to increase enormously due to the availability of higher field strengths and developments in dynamic nuclear polarization (DNP) NMR. At the same time, NMR experiments will be improved using optimal control theory and genetic algorithm optimization. Also, improved solid-state codes with periodic boundary conditions (CASTEP and beyond) for interpreting NMR data will be developed.

For the past thirty or more years the focus of Professor Wasylishen’s research has involved NMR studies of solid materials. He has been particularly interested in improving experimental techniques to enable easier exploration of the NMR periodic table and further realize the potential of modern solid-state NMR spectroscopy. He was co-editor of two texts, NMR Crystallography with R.K. Harris and M.J. Dewar (2009) and NMR of Quadrupolar Nuclei in Solid Materials with S.E. Ashbrook and S. Wimperis (2012). Also, he was co-editor of the Encyclopedia of NMR with R.K. Harris in 2012 (10 Volumes and 6200 pages). He has supervised 25 Ph.D. students and published more than 350 articles in peer-reviewed journals. Rod is currently Lifetime Professor Emeritus at the Department of Chemistry, University of Alberta in Edmonton, Alberta, Canada.

Tea/coffee will be available each day at 10h45.

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