1. Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, 166 10 Prague 6, Czech Republic, Institute of Physical Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany, and Department of Physical Chemistry, Palacký University, Olomouc, 771 46 Olomouc, Czech Republic