1. Depto. Química FundamentalInstituto de QuímicaUniversidade de São Paulo Av. Prof. Lineu Prestes 05508-080 São Paulo – SP Brazil
2. Chemistry DepartmentKøbenhavn Universitet Universistetsparken 5 2100 Copenhagen Denmark
3. Present Adress: Department of Chemistry and BiochemistryUniversität Bern Freiestrasse 3 CH – 3012 Bern Switzerland