1. Department of ChemistryGraduate School of ScienceTohoku University 6-3 Aramaki Azaaoba Aoba-ku Sendai, Miyagi 980-8578 Japan
2. State Key Laboratory of Fine Chemicals and School of ChemistryDalian University of Technology Dalian 116023 P.R. China
3. Research and Analytical Center for Giant MoleculesGraduate School of ScienceTohoku University 6-3 Aramaki Azaaoba Aoba-ku Sendai, Miyagi 980-8578 Japan