1. Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842, Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, California 94117, and Department of Chemistry, University of California, Berkeley, Berkeley, California 94720