1. Department of Inorganic and Analytical ChemistryUniversity of Debrecen Egyetem tér 1 4032 Debrecen Hungary
2. Institute of Nuclear ChemistryUniversity of Mainz Fritz-Strassmann-Weg 2 55128 Mainz Germany
3. Department of ChemistryDurham University South Road Durham DH1 3LE UK
4. Present address: Bracco Imaging-CRB/Trieste Area Science Park. Ed. Q, SS 14, km 163.5 34149 Basovizza Trieste Italy