1. Department of Chemical SciencesUniversity of Padova Via Marzolo 1 35131 Padova Italy
2. Centre for Advanced Electron Spin Resonance (CAESR) Department of Chemistry, Inorganic Chemistry LaboratoryUniversity of Oxford South Parks Road Oxford OX1 3QR UK
3. current affiliation: Institute of Physical ChemistryUniversity of Freiburg Albertstr. 21 79104 Freiburg Germany
4. Department of BiologyUniversity of Padova viale G. Colombo 3 35121 Padova Italy
5. current affiliation: Groningen Biomolecular Science and Biotechnology InstituteUniversity of Groningen 9700 AB Groningen The Netherlands