1. Institute of Organic Chemistry and Center for Nanointegration Duisburg-Essen (CENIDE)University of Duisburg-Essen Universitätsstrasse 7 45141 Essen Germany
2. Mulliken Center for Theoretical ChemistryRheinische Friedrich-Wilhelms-Universität Bonn Beringstrasse 4 53115 Bonn Germany
3. Institute of Organic Chemistry Corrensstr. 40 48149 Münster Germany