1. Department of Chemistry, Queen's University, Kingston, Ont. K7L 3N6, Canada, Department of Physics, Royal Military College, Kingston, Ontario, K7K 5L0 Canada, Département de chimie, Université Laval, Cité Universitaire, Québec, G1K 7P4, Canada, Department of Chemistry, Carleton University, Ottawa, Ontario, K1S 5B6, Canada, Laboratoire de Spectroscopie Moléculaire et Cristalline, Université de Bordeaux I, 33405 Talence, France