1. Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, Department of Material Sciences and Engineering, State University of New York at Stony Brook, Stony Brook, New York 11794-2275, Biology Department, Brookhaven National Laboratory, Upton, New York 11973, and The Dow Chemical Company, Freeport, Texas 77541