1. Department of Chemistry, University of Hawai'i at Mānoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA
2. Department of Chemistry, Allegheny College, 520 N. Main Street, Meadville, PA 16335, USA
3. Department of Chemistry, University of California, 9500 Gilman Drive, La Jolla, San Diego, California 92093, USA