1. Institut für Anorganische Chemie, Universität zu Köln, Greinstrasse 6, D-50939 Köln, Germany
2. Department of Chemistry, University of Zululand, Private bag X1001, KwaDlangezwa 3886, South Africa
3. The School of Chemistry and Manchester Materials Science Centre, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
4. A.M. Butlerov Chemistry Institute, Kazan State University, 420008, Kremlevskaya Street 18, Kazan, Russian Federation