1. Institute of Physical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Str. 4, D-38678 Clausthal-Zellerfeld, Germany
2. Boehringer Ingelheim Pharma GmbH & Co. KG, Innovation Unit, PDB, Birkendorfer Str. 65, D-88397 Biberach/Riss, Germany