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Notes and references
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[3]rotaxanes.
corroborated the threading through the cavity of macrocycle 1a.
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almost unchanged after UV irradiation, but the ring in the loose
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macrocycles of 1a from Job plot experiments (Fig. S31 and S32,
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both [2]- and [3]rotaxane formed (48% and 32%, respectively).
Therefore, the findings from the stepwise syntheses confirm our
hypothesis: the less steric hindrance in the periphery the more
favoured for [3]rotaxane; otherwise, [2]rotaxane will dominate.
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or [3]rotaxane via peripheral steric hindrance. Each of these two
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We are grateful to the National Natural Science Foundation
of China (21572143 and 21971170) and Full-time Postdoctoral
Research and Development Foundation of Sichuan University
(2018SCU12046). The Analytical & Testing Center of Sichuan
University is acknowledged for NMR analysis (Dr Deng).
Conflicts of interest
18 C. F. Ke, R. A. Smaldone, T. Kikuchi, H. Li, A. P. Davis and J. F.
Stoddart, Angew. Chem., Int. Ed., 2013, 52, 381–387.
There are no conflicts to declare.
Chem. Commun.
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