1. University of Messina, ERIC aisbl and CASPE/INSTM; Dept.s MIFT-Industrial Chemistry; V.le F. Stagno D'Alcontres 31 98166 Messina Italy
2. J. Heyrovský Institute of Physical Chemistry; Czech Academy of Science; Dolejškova 3 182 23 Prague 8 Czech Republic
3. Current address: Department of Physical and Macromolecular Chemistry; Faculty of Science; Charles University in Prague; 128 43 Prague 2 Czech Republic