1. Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, Sesto Fiorentino 50019, Italy
2. Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), Via L. Sacconi 6, Sesto Fiorentino 50019, Italy
3. School of Biological and Chemical Sciences, University of Galway, University Road, Galway H91 TK33, Ireland
4. Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, Sesto Fiorentino 50019, Italy