1. Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan, Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, Florida 33176, Department of Applied Chemistry, National Chiao-Tung University, Hsin-chu, Taiwan, Chemistry Department, National Taiwan University, Taipei, Taiwan, and Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan