Zhang Wenyu, Dichtel William R, Stieg Adam Z, Benítez Diego, Gimzewski James K, Heath James R, Stoddart J Fraser
California NanoSystems Institute and Department of Chemistry and Biochemistry, University of California, 405 Hilgard Avenue, Los Angeles, CA 90095, USA.
Proc Natl Acad Sci U S A. 2008 May 6;105(18):6514-9. doi: 10.1073/pnas.0711072105. Epub 2008 Apr 30.
Mechanically interlocked compounds, such as bistable catenanes and bistable rotaxanes, have been used to bring about actuation in nanoelectromechanical systems (NEMS) and molecular electronic devices (MEDs). The elaboration of the structural features of such rotaxanes into macromolecular materials might allow the utilization of molecular motion to impact their bulk properties. We report here the synthesis and characterization of polymers that contain pi electron-donating 1,5-dioxynaphthalene (DNP) units encircled by cyclobis(paraquat-p-phenylene) (CBPQT(4+)), a pi electron-accepting tetracationic cyclophane, synthesized by using the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The polyrotaxanes adopt a well defined "folded" secondary structure by virtue of the judicious design of two DNP-containing monomers with different binding affinities for CBPQT(4+). This efficient approach to the preparation of polyrotaxanes, taken alongside the initial investigations of their chemical properties, sets the stage for the preparation of a previously undescribed class of macromolecular architectures.
机械互锁化合物，如双稳态索烃和双稳态轮烷，已被用于在纳米机电系统（NEMS）和分子电子器件（MED）中实现驱动。将此类轮烷的结构特征引入高分子材料中，可能会利用分子运动来影响其整体性质。我们在此报告了聚合物的合成与表征，该聚合物包含被环双（对苯二酚对苯撑）（CBPQT(4+)）环绕的π电子供体1,5 - 二氧萘（DNP）单元，CBPQT(4+)是一种π电子受体四价阳离子环番，通过铜（I）催化的叠氮化物 - 炔烃环加成反应（CuAAC）合成。通过巧妙设计两种对CBPQT(4+)具有不同结合亲和力的含DNP单体，聚轮烷呈现出明确的“折叠”二级结构。这种制备聚轮烷的有效方法，连同对其化学性质的初步研究，为制备一类前所未有的高分子结构奠定了基础。
