1. Department of Chemistry and Pharmacy; University of Erlangen-Nürnberg; Henkestr. 42 91054 Erlangen Germany
2. Department of Chemistry; University of Cologne; Greinstraße 4 50939 Cologne Germany
3. Institute of Molecular Enzyme Technology; Heinrich-Heine-University of Düsseldorf; Research Centre Jülich; Stetternicher Forst 52426 Jülich Germany
4. Faculty of Chemistry; Bielefeld University; Universitätsstr. 25 33615 Bielefeld Germany