1. Catalysis and Chemical Technologies Department, Sandia National Laboratories, Albuquerque, New Mexico 87185-0710, Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, FB1-Institut für Experimentelle Physik, Universität Bremen, P.O. Box 330440, 28334 Bremen, Germany, and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556