State Key Laboratory of Supramolecular Structure and Materials;
College of Chemistry;
Jilin University;
Changchun 130012;
P. R. China;
Department of Chemistry;
Tsinghua University;
Beijing 100084;
P. R. China;
School of Science;
Beijing Jiaotong University;
Beijing 100044;
P. R. China;
Department of Physics;
Beijing Normal University;
Beijing 100875;
P. R. China;