1. Natural and Medical Sciences Institute, Eberhardstr. 29, D-72762 Reutlingen, Germany / Institute for Physical and Theoretical Chemistry, University of Tübingen, D-72076 Tübingen, Germany
2. Institute for Physical and Theoretical Chemistry, University of Tübingen, D-72076 Tübingen, Germany
3. Institute for Chemical Plant Physiology, University of Tübingen, D-72076 Tübingen, Germany