Speed Tuning of the Formation/Dissociation of a Metallorotaxane |
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Authors: | Dr Yoko Sakata Ryosuke Nakamura Toshihiro Hibi Prof Dr Shigehisa Akine |
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Institution: | Graduate School of Natural Science and Technology, Kanazawa University Kakuma-machi, Kanazawa, 920-1192 Japan |
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Abstract: | Switching between the formation/dissociation of rotaxanes is important to control the function of various types of rotaxane-based materials. We have developed a convenient and simple strategy, the so-called “accelerator addition”, to make a static rotaxane dynamic without apparently affecting the chemical structure. As an interlocked molecule that enables tuning of the formation/dissociation speed, a metallorotaxane was quantitatively generated by the complexation of a triptycene-based dumbbell-shaped mononuclear complex, PdL2]2+ (L=2,3-diaminotriptycene), with 27C9. As a result of the inertness of the Pd2+-based coordination structure, the metallorotaxane was slowly formed (the static state). This rotaxane formation was accelerated 27 times simply by adding Br− as an accelerator (the dynamic state). A similar drastic acceleration was also demonstrated during the dissociation process when Cs+ was added to the metallorotaxane to form the free axle PdL2]2+ and the 27C9-Cs+ complex. |
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Keywords: | Crown Ether Kinetics Palladium Rotaxanes Stimuli-Responsive Molecule |
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