1. Institut für Anorganische Chemie, RWTH Aachen, Landoltweg
1, D-52074 Aachen, Germany
2. Physikalisches Institut, Universität Münster, Wilhelm-Klemm-Strasse
10, D-48149 Münster, Germany
3. Department of Chemistry, University of California Riverside, California 92521, United States
4. Instituto de Física de São
Carlos, Universidade de São Paulo, São Carlos−SP 13566-590, Brazil