1. Process Technology Research Laboratories; Daiichi Sankyo Co., Ltd.; Edogawa-ku Tokyo 134-8630 Japan
2. Research and Analytical Center for Giant Molecules; Graduate School of Science; Tohoku University; Aoba-ku Sendai 980-8578 Japan
3. Department of Chemistry; Graduate School of Science; Tohoku University; Aoba-ku Sendai 980-8578 Japan