1. Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Lavrentiev Avenue 3, Novosibirsk 630090, Russia, Institute of Physical Chemistry, University of Karlsruhe, Kaiserstr. 12, D-76128 Karlsruhe, Germany, Institute of Nanotechnology, Forschungszentrum Karlsruhe, P.O. Box 3640, D-76021 Karlsruhe, Germany, and Institute of Inorganic Chemistry, University of Karlsruhe, Engesserstr. 15, D-76128 Karlsruhe, Germany