1. Department of Chemistry and Institute of Materials Science, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut 06032, School of Chemistry, National University of Ireland at Galway, Ireland and Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892