1. Max‐Planck‐Institut für Bioanorganische Chemie, Stiftstrasse 34–36, 45470 Mülheim an der Ruhr, Germany, Fax: +49‐208‐306 3952
2. Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322, U.S.A
3. EPSRC National UK EPR Facility and Service, Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K