1. Institut für Physikalische und Theoretische Chemie, Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany and Max-Planck Institute for Bioinorganic Chemistry, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany, Medical Biotechnology Center, University of Maryland Biotechnology Institute and Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, Department of Pharmaceutical Sciences and Center for EPR Imaging, University of Maryland School of Pharmacy,...