1. Department
of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
2. Department
of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
3. Bruker Biospin Ltd., Billerica, Massachusetts 01821, United States
4. Department
of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58102, United States