1. Department of Chemistry and Biochemistry-0358, University of California at San Diego, La Jolla, California 92093-0358, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, Department of Chemistry, University of Delaware, Newark, Delaware 19716, and Department of Chemistry, and Molecular Structure Center, Indiana University, Bloomington, Indiana, 47405