1. Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
2. School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive,
Atlanta, Georgia 30332-0400, United States
3. Physikalisches Institut and Center
for Nanotechnology (CeNTech), Universität Münster, Heisenbergstrasse 11, 48149 Münster, Germany