1. Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
2. Magnetic Resonance Center (CERM), University of Florence and Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine, Via L. Sacconi 6, 50019 Sesto Fiorentino (FI), Italy
3. Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy