1. Department of Chemistry Johannes Gutenberg University Mainz Duesbergweg 10–14 55128 Mainz Germany
2. Department of Chemistry Johannes Gutenberg University Mainz Johann-Joachim Becherweg 30 55128 Mainz Germany
3. Center for Biomolecular Magnetic Resonance (BMRZ) Goethe-University Frankfurt Max-von-Laue Str. 9 60438 Frankfurt/M Germany
4. Department Materials Engineering Science Graduate School of Engineering Science Osaka University Toyonaka Osaka 560–8531 Japan