1. Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
2. Nuclear Magnetic Resonance Laboratory, Molecular Structures Group, University of Kansas, 2034 Becker Drive, Lawrence, Kansas 66047, United States
3. Department of Chemistry and Biochemistry, University of Notre Dame, 149 Stepan Chemistry, Notre Dame, Indiana 46556, United States