1. Contribution from the Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka 142432 Russia, Forschungszentrum Karlsruhe, Institute for Nanotechnology, Karlsruhe 76021 Germany, Institut für Anorganische und Analytische Chemie der Freien Universität, Berlin D14195 Germany, Chemistry Department, Moscow State University, Moscow 119992 Russia, and Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523