1. Institute for Inorganic Chemistry, University of Duisburg-Essen, Universitätsstraße 5–7, 45117 Essen, Germany
2. Institute for Organic Chemistry, University of Duisburg-Essen, Universitätsstraße 5–7, 45117 Essen, Germany
3. Center for Nanointegration Duisburg-Essen (Cenide), University of Duisburg-Essen, Carl-Be, Germany