1. Centre de RMN à Très Hauts Champs, FRE 2034 (CNRS/Université Claude Bernard Lyon 1/Ecole Normale Supérieure de Lyon), University of Lyon, 69100 Villeurbanne, France
2. Department of Chemistry “Ugo Schiff” and CERM, University of Florence, 50019 Sesto Fiorentino, Italy
3. Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland