1. Institute of Inorganic ChemistryUniversity of Regensburg 93040 Regensburg Germany
2. University of RegensburgInstitute of Organic Chemistry 93040 Regensburg Germany
3. Current address: University of HamburgDepartment of Chemistry 20146 Hamburg Germany
4. TU DresdenFaculty of Chemistry and Food ChemistryChair of Inorganic Molecular Chemistry 01062 Dresden Germany