1. Department of Chemistry, Circular Road, University of the West Indies, St. Augustine Campus, St. Augustine, Trinidad and Tobago
2. Department of Chemistry, 2 Plymouth Close, University of the West Indies, Mona Campus, Kingston 7, Jamaica, Fax: +1‐876‐977‐1835, http://wwwchem.uwimona.edu.jm/chmw.html
3. Department of Chemistry, George Washington University, 725 21st Street, N.W., Washington, DC 20052, USA