1. Department of Chemistry; Graduate School of Science; Tohoku University; Aoba-ku Sendai 980-8578 Japan
2. Isobe Degenerate π-Integration Project; Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency; Aoba-ku Sendai 980-8577 Japan
3. Advanced Institute for Materials Research; Tohoku University; Aoba-ku Sendai 980-8577 Japan
4. Department of Chemistry; University of Tokyo; Hongo, Bunkyo-ku Tokyo 113-0033 Japan