1. Graduate School of Pharmaceutical Sciences; Tohoku University; Aoba 6-3, Aramaki, Aoba-ku Sendai 980-8578 Japan
2. ERATO, Isobe Degenerate π-Integration Project and Advanced Institute for Materials Research (AIMR); 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
3. AIMR and Department of Chemistry; Tohoku University; Aoba 6-3, Aramaki, Aoba-ku Sendai 980-8578 Japan