title: An Unprecedented Two-Fold Nested Super-Polyrotaxane: Sulfate-Directed Hierarchical Polythreading Assembly of Uranyl Polyrotaxane Moieties.
abstract: 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 )3 O(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.
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Mei
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Qun-Yan
authors.initials: QY
authors.lastname: Wu
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Li-Yong
authors.initials: LY
authors.lastname: Yuan
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: An
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Zhen-Ni
authors.initials: ZN
authors.lastname: Xie
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.
authors.forename: Kong-Qiu
authors.initials: KQ
authors.lastname: Hu
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China.|School of Radiological and Interdisciplinary Sciences and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, 215123, P.R. China.
authors.forename: Zhi-Fang
authors.initials: ZF
authors.lastname: Chai
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA. pburns@nd.edu.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burns
authors.affiliation: Laboratory of Nuclear Energy Chemistry and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P.R. China. shiwq@ihep.ac.cn.
authors.forename: Wei-Qun
authors.initials: WQ
authors.lastname: Shi
keywords: actinides; polythreading; rotaxanes; supramolecular chemistry; uranium