1. Department of Chemistry, Kiev National Taras Shevchenko University, 01601 Kiev, Ukraine, Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw, Poland, Department of Chemistry, University of Joensuu, P.O. Box 111, 80101 Joensuu, Finland, and Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany