Dr. Kathryn E. Preuss, University of Guelph

Department of Chemistry

Visiting Speaker

Professor Dr. Kathryn E. Preuss, Assoc. Prof.

Tier II Canada Research Chair in the Chemistry of Molecular Materials

University of  Department of Chemistry

University of Guelph

Member of the Guelph-Waterloo Center for Graduate Work in Chemistry: (GWC)²

Email: kpreuss@uoguelph.ca

                         will present a seminar entitled:

"Paramagnetic Ligand Designs using
Thiazyl and Selenazyl Ring Architectures:
Conductivity and Magnetic Properties"

Thiazyl-based radicals, and their selenium analogs, continue to enjoy extensive investigation as potential neutral radical conductors, charge transfer salt donors (i.e. radical cations), organic molecular magnets, and bistable systems. Broadly stated, the goal of our research is to develop paramagnetic ligands from thiazyl radicals (and their Se analogs) in order to create new molecular species with enhanced magnetic and/or conductive properties. Understanding how to design and manipulate these properties at a molecular level is important to the development of spintronic materials (i.e., materials that make of use the quantum spin of charge carriers in a conductor or semiconductor).  

To date, we have published a number of metal complexes incorporating spin-bearing ligands based on the 1,2,3,5-dithiadiazolyl (DTDA) radical. These studies will be discussed in context as the foundation of our current research. In addition, new, unpublished results showing intermolecular ferromagnetic coupling between metal-DTDA complexes will be presented. Current results from new projects that combine a paramagnetic thiazyl or selenazyl moiety with quinone moieties will also be presented. These include a charge transfer salt of a radical anion species that shows activated conductivity and intermolecular magnetic coupling and  a novel coordination species of a neutral radical ligand that pi-stacks in the solid state.

Figure: Pyrimidyl-DTDA complex of Ni(hfac)₂; S(yellow), N(blue), O(red), Ni(green)

Friday, September 11^th.  at 11:00 location ST 148                   Host :  Dr T. Chivers