An Unprecedented Two-Fold Nested Super-Polyrotaxane: Sulfate-Directed Hierarchical Polythreading Assembly of Uranyl Polyrotaxane Moieties

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• 作者：Dr. Lei Mei ; Dr. Qun-yan Wu ; Dr. Li-yong Yuan ; Dr. Lin Wang ; Shu-wen An ; Zhen-ni Xie ; Dr. Kong-qiu Hu ; Prof. Zhi-fang Chai ; Prof. Peter C. Burns and Prof. Wei-qun Shi
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：August 1, 2016
• 年：2016
• 卷：22
• 期：32
• 页码：11329-11338
• 全文大小：5732K
• ISSN：1521-3765

文摘

The hierarchical assembly of well-organized submoieties could lead to more complicated superstructures with intriguing properties. We describe herein an unprecedented polyrotaxane polythreading framework containing a two-fold nested super-polyrotaxane substructure, which was synthesized through a uranyl-directed hierarchical polythreading assembly of one-dimensional polyrotaxane chains and two-dimensional polyrotaxane networks. This special assembly mode actually affords a new way of supramolecular chemistry instead of covalently linked bulky stoppers to construct stable interlocked rotaxane moieties. An investigation of the synthesis condition shows that sulfate can assume a vital role in mediating the formation of different uranyl species, especially the unique trinuclear uranyl moiety [(UO₂)₃O(OH)₂]²⁺, involving a notable bent [O=U=O] bond with a bond angle of 172.0(9)°. Detailed analysis of the coordination features, the thermal stability as well as a fluorescence, and electrochemical characterization demonstrate that the uniqueness of this super-polyrotaxane structure is mainly closely related to the trinuclear uranyl moiety, which is confirmed by quantum chemical calculations.