1. Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
2. Department of Inorganic and Analytical Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
3. Dipartimento di Chimica e Chimica Industriale University of Pisa Via G. Moruzzi 13 56124 Pisa Italy
4. Laboratory of Crystallography University of Geneva Quai Ernest Ansermet 24 1211 Geneva 4 Switzerland
5. Department of Biochemistry University of Geneva Quai Ernest Ansermet 24 1211 Geneva 4 Switzerland