1. Department of Chemistry—Ångström Laboratory, Uppsala University, SE-75121 Uppsala, Sweden
2. Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovskeho nam. 2, 162 06 Prague 6, Czech Republic
3. Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 40 Prague 2, Czech Republic