NSERC Postdoctoral Fellow, 1981-1983, Brookhaven National Laboratory;
NSERC University Research Fellow, 1983-1993.
Chernoff Hall, CHE 506 (Office), CHE 535 (Lab)
(613) 533-2617 (Office)
(613) 533-6000 ext. 74664 (Lab)
Our research interests are concerned with the kinetics and mechanisms of ligand substitution and electron transfer reactions of transition metal complexes in solution. These studies are aimed at a better understanding of the relationships between the structure and reactivity of metal-ligand complexes. One aspect of our work involves research into the effects of the inclusion of reactants in host molecules such as cyclodextrins and calixarenes on the kinetics and mechanisms of their reactions in solution. These host molecules act as second coordination spheres for the transition metal complexes, and have significant effects on the rates of ligand substitution and electron transfer processes. NMR and UV-visible spectroscopy and kinetic methods, with metal probes such as Fe(CN)5L3-, are used to determine the binding strengths and guest-host orientations in studies on molecular recognition.
We are also interested in the synthesis of self-assembling supramolecular complexes containing transition metal centres. These molecular assemblies have future applications as "intelligent" synthetic nanostructures, such as molecular wires, switches, and machines, in which the components are held together by non-covalent, intermolecular bonding interactions. Among these supramolecular complexes are rotaxanes. These are chemical species in which a cyclic molecular bead is threaded by a linear chain bearing bulky end units which prevent the complex from dissociating into its cyclic and linear molecular components. One series of self-assembling rotaxane complexes recently prepared in our laboratory is shown on this page; a-cyclodextrin is threaded by a bis-(bipyridinium) dicationic ligand, which is then capped by two [Fe(CN)5]3- units.