1. Department of Chemistry and Research Institute of Basic Sciences, Wonkwang University, Iksan, Jeonbuk 570-749, S. Korea, CAE Group, Central R & D Institute, Samsung Electro-Mechanics Co. Ltd., Suwon 443-803, Korea, Department of Chemistry, Pusan National University, Pusan 609-735, S. Korea, Department of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3, and Department of Material Science and Engineering, Cornell University, 214 Bard Hall, Ithaca, New York 14853-1501