Redox-Responsive Viologen-Mediated Self-Assembly of CB[7]-Modified Patchy Particles

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• 作者：Farah Benyettou ; Xiaolong Zheng ; Elizabeth Elacqua ; Yu Wang ; Parastoo Dalvand ; Zouhair Asfari ; John-Carl Olsen ; Dong Suk Han ; Na’il Saleh ; Mourad Elhabiri ; Marcus Weck ; Ali Trabolsi
• 刊名：Langmuir
• 出版年：2016
• 出版时间：July 19, 2016
• 年：2016
• 卷：32
• 期：28
• 页码：7144-7150
• 全文大小：420K
• 年卷期：0
• ISSN：1520-5827

文摘

Sulfonated surface patches of poly(styrene)-based colloidal particles (CPs) were functionalized with cucurbit[7]uril (CB[7]). The macrocycles served as recognition units for diphenyl viologen (DPV²⁺), a rigid bridging ligand. The addition of DPV²⁺ to aqueous suspensions of the particles triggered the self-assembly of short linear and branched chainlike structures. The self-assembly mechanism is based on hydrophobic/ion-charge interactions that are established between DPV²⁺ and surface-adsorbed CB[7]. DPV²⁺ guides the self-assembly of the CPs by forming a ternary DPV²⁺⊂(CB[7])₂ complex in which the two CB[7] macrocycles are attached to two different particles. Viologen-driven particle assembly was found to be both directional and reversible. Whereas sodium chloride triggers irreversible particle disassembly, the one-electron reduction of DPV²⁺ with sodium dithionite causes disassembly that can be reversed via air oxidation. Thus, this bottom-up synthetic supramolecular approach allowed for the reversible formation and directional alignment of a 2D colloidal material.