可切换中性双稳态轮烷

Switchable neutral bistable rotaxanes.

作者信息

Vignon Scott A, Jarrosson Thibaut, Iijima Takahiro, Tseng Hsian-Rong, Sanders Jeremy K M, Stoddart J Fraser

机构信息

California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA.

出版信息

J Am Chem Soc. 2004 Aug 18;126(32):9884-5. doi: 10.1021/ja048080k.

DOI:10.1021/ja048080k

PMID:15303838

Abstract

Two switchable neutral bistable [2]rotaxanes have been synthesized, and their chemically induced mechanical switching has been studied in solution by 1H NMR spectroscopy. One of the rotaxanes was prepared by a thermodynamically controlled slippage mechanism, while the other rotaxane was obtained by a dynamic covalent chemistry protocol involving the assembly of its dumbbell component by olefin metathesis. The recognition sites present in the rod section of the dumbbell component, namely, naphthodiimide (NpI) and pyromellitic diimide (PmI) residues, were chosen in the knowledge that the ring component, 1,5-dinaphtho[38]crown-10 (1/5DNP38C10), will bind preferentially to the NpI site. However, upon introduction of Li+ ions into the solution, a 1:2 complex is formed between the PmI site, encircled by the 1/5DNP38C10 ring and two Li+ ions. Since this complex is more stable overall than the binding between the 1/5DNP38C10 ring and the NpI site, the ring component moves from the NpI site to the PmI one. This mechanical movement can be reversed by adding an excess of [12]crown-4 to the solution to act as a sequestering agent for the Li+ ions.

摘要

已合成了两种可切换的中性双稳态[2]轮烷，并通过¹H NMR光谱在溶液中研究了它们的化学诱导机械切换。其中一种轮烷是通过热力学控制的滑移机制制备的，而另一种轮烷则是通过动态共价化学方法获得的，该方法涉及通过烯烃复分解组装其哑铃形组件。选择哑铃形组件杆部中的识别位点，即萘二酰亚胺（NpI）和均苯四甲酸二酰亚胺（PmI）残基，是因为已知环组件1,5-二萘并[38]冠-10（1/5DNP38C10）将优先与NpI位点结合。然而，当将Li⁺离子引入溶液中时，在被1/5DNP38C10环包围的PmI位点与两个Li⁺离子之间形成1:2配合物。由于该配合物总体上比1/5DNP38C10环与NpI位点之间的结合更稳定，环组件从NpI位点移动到PmI位点。通过向溶液中加入过量的[12]冠-4作为Li⁺离子的螯合剂，可以使这种机械运动逆转。