title: Discrete stimuli-responsive multirotaxanes with supramolecular cores constructed through a modular approach.
abstract: The synthesis of discrete multirotaxanes with well-defined structures remains a great challenge. Herein, we present the successful construction of diverse discrete multirotaxanes with well-defined supramolecular metallacycles as cores by a modular approach. Moreover, these novel multirotaxanes featured a stimuli-responsive property that enabled the introduction and removal of the bromide anion by taking advantage of dynamic nature of the supramolecular metallacycle scaffold. Through the combination of rotaxane-containing prefunctionalized building blocks with the corresponding different organoplatinum(II) acceptor building blocks (60, 120, or 180°), diverse discrete multirotaxanes with well-defined metallacycles (rhomboid or hexagon) as cores as well as certain numbers of rotaxane units were successfully obtained quantitatively by means of coordination-driven self-assembly. Furthermore, owing to the existence of a dynamic metallacycle as the supramolecular cores, the resultant multirotaxanes showed anion-induced disassembly and reassembly properties, which allowed for the reversible transformation between multirotaxanes and the corresponding individual rotaxane-containing building blocks. Therefore, this research not only enriches the family of discrete multirotaxanes, but also provides a novel strategy for the construction of "smart" stimuli-responsive multirotaxane systems.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai 200062 (P.R. China), Fax: (+86) 21-6223-5137.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.forename: Xu-Qing
authors.initials: XQ
authors.lastname: Wang
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Ren
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Chen
authors.forename: Jianqiu
authors.initials: J
authors.lastname: Ma
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Li
authors.forename: Yihua
authors.initials: Y
authors.lastname: Yu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Tan
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Yang
keywords: metallacycles; rotaxanes; self-assembly; stimulus response; supramolecular chemistry