1. Department
of Chemistry, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
2. Department
of Biomolecular Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
3. JST
ERATO, Isobe Degenerate π-Integration Project and Advanced Institute
for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
4. Department
of Chemistry, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan