1. CNR-ISTM Istituto di Scienze e Tecnologie Molecolari, via Golgi 19; Milano 20133 Italy
2. Istituto Lombardo Accademia di Scienze e Lettere, Via Brera 28; Milano 20121 Italy
3. Dipartimento di Chimica; Università degli Studi di Milano, via Golgi 19; Milano 20133 Italy
4. Department of Chemistry; Dalhousie University; Halifax Nova Scotia Canada B3H 4J3
5. Department of Chemistry and Physics; Mount Saint Vincent University; Halifax Nova Scotia Canada B3M 2J6
6. Department of Chemistry; Saint Mary's University; Halifax Nova Scotia Canada B3H 3C3
7. Dép. de chimie; Université Laval; Québec Québec Canada G1V 0A6