Fig. 8: ¹H–¹H NOESY spectra of the [3]rotaxanes.

Partial ¹H-¹H NOESY spectra (600 MHz, CD₃CN, 298 K) of the [3]rotaxane translational isomers (a) R3•10PF₆, and (b) R4•14PF₆. Key peaks on the 1D projections are annotated in the complete spectra given in the Supplementary Information. The graphical depictions are labeled to present the subscripts denoting the different CBPQT⁴⁺ rings. a Subscript M denotes the ring on the middle chain, T the terminal chain. Crosspeaks between CBPQT⁴⁺ and both the central (H-15 to H-20) and terminal (H-41 to H-50) collecting chains indicate that the rings are located in distinct regions of the DP⁶⁺ pump. b Subscript IPP denotes the ring closest to the IPP, and S the ring closest the stopper. Crosspeaks between CBPQT⁴⁺_IPP with H-35 and H-37 of the second IPP unit, and the H-38 to H-41 alkane protons reveal that this ring is located on the first half of the terminal collecting chain. Crosspeaks between CBPQT⁴⁺_S with the H-46, H-47, H-50, H-51, and H-53 resonances indicate that this ring is positioned on the second half of the terminal collecting chain.