1. Fujian Key Laboratory of Polymer Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, College of Chemistry & Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, P. R. China
2. Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Shantou, Guangdong 515063, P. R. China
3. Department of Chemistry, University of Surrey, Guildford GU2 7XH, Surrey, U.K.