At first glance, it seems clear that the magnetic properties of a material are determined by a the absence, presence, quantity, and interaction of unpaired electrons. However, the design of a molecule-based material with predictable magnetic properties relies on more than just the elements, oxidation states, and molecular architecture: it relies on the supramolecular structure and the multitude of weak interactions between molecules. Seemingly small changes in the intermolecular contacts can result in dramatic differences in magnetic properties. Understanding and, ultimately predicting the crystal packing of paramagnetic species is of value in the search for new materials for quantum computing, data storage, sensor design, and other technological advances.

In this talk, a variety of examples of molecular and supramolecular structures based on thiazyl radicals and their coordination to diamagnetic and paramagnetic metal centers will be presented. Synthesis, characterization, and qualitative and quantitative computational analyses are used to understand magnetic properties. Periodic-boundary and finite-molecule calculations are used as a means of rationalizing crystal packing, providing a step toward structure and property predictions.

Prof. Kathryn Preuss earned a Ph.D. in Inorganic Chemistry in 2000 from the University of Waterloo, under the supervision of Prof. Richard T. Oakley and was the recipient of the Alice Wilson Award of the Royal Society of Canada in 2001. Funded by an NSERC PDF, Kathryn pursued a post-doc in Physical Organic Chemistry at the University of Colorado (2000-01; Prof. Josef Michl) and Magnetochemistry at North Carolina State University (2001-02; Prof. David A. Shultz). In 2002, Kathryn started as an Assist. Prof. at the University of Guelph, where she is now a tenured Professor. From 2009 to 2019, Kathryn held a Tier II CRC. Currently, Kathryn is the Chair of the Department of Chemistry, serving in this role since June 2020. She also holds a Research Leadership Chair (2021-24) at the University of Guelph, serves on the NSERC DG Evaluation Group #1504 (2021-24), and is Assoc. Editor of Crystal Growth & Design, an ACS journal. Kathryn is very proud of her excellent research group, including students from around the world, and supporting increased Indigeneity in STEM in Canada.