1. Department Chemistry, University of Alabama, Tuscaloosa, Alabama 35487-0336, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France, Department of Physical and Theoretical Chemistry, J.W. Goethe Universität, Frankfurt am Main D-60439, Germany, Department of Physics & Astronomy, Georgia State University, Atlanta, Georgia 30303, and Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310