1. MOE Key Laboratory of Cluster Science; School of Chemistry; Beijing Institute of Technology; Beijing 100081 P. R. China), Fax: (+86)10-6891-8572
2. College of Science; Hebei University of Science and Technology, Shijiazhuang; Hebei 050018 P. R. China
3. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry; Zhejiang Normal University, Jinhua; Zhejiang 321004 P. R. China
4. Department of Chemistry, Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province; Shantou University, Shantou; Guangdong 515063 P. R. China