1. Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, Laboratoire de Chimie Physique, UMR 8000, CNRS, Electrochimie et Photoélectrochimie, Université Paris-Sud, Bâtiment 350, 91405 Orsay Cedex, France, and Department of Chemistry, Hunter College of the City University of New York, 695 Park Avenue, New York 10021