Organogel Formation by a Cholesterol-Stoppered Bistable [2]Rotaxane and Its Dumbbell Precursor

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• 作者：Yan-Li Zhao ; Ivan Aprahamian ; Ali Trabolsi ; Natalia Erina ; J. Fraser Stoddart
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：May 21, 2008
• 年：2008
• 卷：130
• 期：20
• 页码：6348 - 6350
• 全文大小：1510K
• 年卷期：v.130,no.20(May 21, 2008)
• ISSN：1520-5126

文摘

The switching properties, gelation behavior, and self-organization of a cholesterol-stoppered bistable [2]rotaxane containing a cyclobis(paraquat-p-phenylene) ring and tetrathiafulvalene/1,5-dioxynaphthalene recognition units situated in the rod portion of the dumbbell component have been investigated by electrochemical, spectroscopic, and microscopic means. The cyclobis(paraquat-p-phenylene) ring in the [2]rotaxane can be switched between the tetrathiafulvalene and 1,5-dioxynaphthalene recognition units by addressing the redox properties of the tetrathiafulvalene unit. The organogels can be prepared by dissolving the [2]rotaxane and its dumbbell precursor in a CH₂Cl₂/MeOH (3:2) mixed solvent and liquified by adding the oxidant Fe(ClO₄)₃. Direct evidence for the self-organization was obtained from AFM investigations which have shown that both of the [2]rotaxane and its dumbbell precursor form linear superstructures which we propose are helical in nature.