1. Department of Chemistry, Dalhousie University,
P.O. Box 15000, Halifax, Nova Scotia B3H 4R2, Canada
2. Department
of Chemistry, Acadia University, 6 University Avenue, Wolfville, Nova Scotia B4P 2R6, Canada
3. Department of Chemistry
and Biochemistry, University of North Carolina at Greensboro, 301 McIver
Street, Greensboro, North
Carolina 27402, United States