1. Department of Inorganic and Analytical Chemistry; University of Geneva; 30 quai Ernest Ansermet 1211 Geneva 4 Switzerland
2. Laboratory for X-ray Crystallography; University of Geneva; 24 quai Ernest Ansermet 1211 Geneva 4 Switzerland
3. Departement für Chemie und Biochemie; Universität Bern; Freiestrasse 3 3012 Bern Switzerland
4. Department of Chemistry; Memorial University of Newfoundland; St. John's NL A1B 3X7 Canada