1. Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines L2S 3A1, Ontario, Canada
2. Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
3. Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
4. Department of Physics, City College of New York New York, New York 10031, United States