1. Department of Chemistry and Biochemistry, 236 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States
2. Molecular Imaging Center, Mallinckrodt Institute for Radiology, Washington University School of Medicine, Campus Box 8225, 510 S. Kingshighway Boulevard, St. Louis, Missouri 63110, United States
3. Department of Chemistry and Biochemistry, University of Missouri St. Louis, 315 Benton Hall, One University Boulevard, St. Louis, Missouri 63121, United States
4. Freimann Life Science Center, University of Notre Dame, 400 Galvin Life Science, Notre Dame, Indiana 46556, United States