1. Department of Chemistry Queen's University 90 Bader Lane Kingston ON K7L3N6 Canada
2. Department of Chemistry McGill University 801 Sherbrooke St. West Montreal QC H3A0B8 Canada
3. Institut Européen de Chimie et Biologie 2 rue Escarpit F-33607 Pessac France
4. Laboratoire d'Optique et Biosciences École Polytechnique CNRS INSERM Institut Polytechnique de Paris 91128 Palaiseau cedex France