1. Department
of Chemistry, Queen’s University, 90 Bader Lane, Kingston,
Ontario, K7L 3N6, Canada
2. National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario, K1A
0R6, Canada
3. Center of Interdisciplinary
Magnetic
Resonance, National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, United
States