Sequential 鈥淐lick鈥?Approach to Polyhedral Oligomeric Silsesquioxane-Based Shape Amphiphiles

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• 作者：Kan Yue ; Chang Liu ; Kai Guo ; Xinfei Yu ; Mingjun Huang ; Yiwen Li ; Chrys Wesdemiotis ; Stephen Z. D. Cheng ; Wen-Bin Zhang
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：October 23, 2012
• 年：2012
• 卷：45
• 期：20
• 页码：8126-8134
• 全文大小：476K
• 年卷期：v.45,no.20(October 23, 2012)
• ISSN：1520-5835

文摘

This paper reports a highly efficient and modular sequential 鈥渃lick鈥?approach for the syntheses of shape amphiphiles based on polymer-tethered polyhedral oligomeric silsesquioxane (POSS). This approach combines both 鈥済rafting-to鈥?and 鈥減ost-functionalization鈥?strategies. It involves the copper-catalyzed Huisgen [3 + 2] cycloaddition (CuAAC) for POSS鈥損olymer ligation and subsequent thiol鈥揺ne addition reaction for POSS cage functionalization. Starting from a readily available POSS precursor bearing one alkyne and seven vinyl groups (VPOSS鈥揳lkyne), the CuAAC reaction is effective in ensuring the stoichiometric bonding between POSS and azide-functionalized polymers, with no need for fractionation in the purification process. The modularity was demonstrated in two representative polymer systems, hydrophobic polystyrene (PS) and hydrophilic poly(ethylene oxide) (PEO), by the synthesis of VPOSS鈥揚S and VPOSS鈥揚EO. The thiol鈥揺ne reaction was subsequently applied to convert all the vinyl groups on the POSS cage quantitatively into various functional groups, including carboxylic acids, hydroxyls, and alkyls, thereby introducing amphiphilicity to drive self-assembly. Such shape amphiphiles are novel model systems for the study of their self-assembly behaviors, hierarchal structure formation, and functional properties in both the solution and bulk states. Aiming to fulfill the 鈥渃lick鈥?philosophy, the sequential 鈥渃lick鈥?approach described here is robust and efficient for rapid construction of functional shape amphiphiles with complex structures and diverse molecular architectures.