doi:10.1038/nature20798 Supplementary Tables Table S1: Kinetic parameters for porphyrin torsional rotation in c-p6 6+ and c-p6 12+ from 1 H EXSY. Table S2: Calculated (NICS, ppm) and experimental ( δ, ppm) parameters. Table S3: 1 H and 13 C NMR chemical shifts for c-p6 T6, c-p6 T6 4+, c-p6 T6 6+ and c-p6 T6 12+. Table S4: Chemical shift differences for the template protons in c-p6 T6, c-p6 T6 6+ and c-p6 T6 12+. Table S5: NICS(0) for c-p6 in different oxidation states, with different DFT functionals. Supplementary Figures Fig. S1: Chemical structures of oxidants used in this study. Fig. S2: Fit of 1 H EXSY data for oʹ/o exchange in c-p6 6+. Fig. S3: Fit of 1 H EXSY data for oʹ/o exchange in c-p6 12+. Fig. S4: Experimental magnetic susceptibility during an NMR titration of DIBAHA F into c-p6 T6. Fig. S5: NMR assignment labels used for (A) linear oligomers and (B) c-p6 T6. Fig. S6: Representations of c-p6 describing the xy, xz and yz planes. Fig. S7: NICS zz grids for c-p6 6+ in (A) the xz plane and (B) the yz plane of the molecule. Fig. S8: NICS(0) grids for neutral, 4+, 6+ and 12+ c-p6. Fig. S9: ACID plots for an applied magnetic field along the +z axis of c-p6 neutral, 4+, 6+ and 12+. Fig. S10: 1 H NMR spectra of the 2N+ oxidation states of c-p6, c-p8 T8, c-p10, c-p11 and c-p12. Fig. S11: 1 H NMR of l-p1, l-p2 and l-p4 in their diamagnetic neutral, 1+ and 2+ oxidation states Fig. S12: Square wave voltammetry of l-p1, l-p2 and c-p6 T6, in CH 2 Cl 2 (0.1 M Bu 4 PF 6 ). Fig. S13: Thin layer spectroelectrochemistry of c-p6 T6 in CH 2 Cl 2 (0.1 M Bu 4 NPF 6 ). Fig. S14: Frontier orbitals of l-p2 in its neutral, 2+ and 4+ oxidation states. Fig. S15: Comparison of template-free c-p6 NMR spectra in its neutral, 6+ and 12+ oxidation states. Fig. S16: Comparison of c-p6 6+ NMR spectra with and without template T6. Fig. S17: VT 1 H NMR of c-p6 6+. Fig. S18: VT 1 H NMR of c-p6 12+. Fig. S19: NOESY of c-p6 T6 4+. Fig. S20: NOESY of c-p6 T6 6+. Fig. S21: NOESY of c-p6 T6 12+. Fig. S22: TOCSY (t mix = 60 ms) of c-p6 T6 4+. Fig. S23: Expanded COSY of c-p6 T6 6+. Fig. S24: Expanded COSY of c-p6 T6 6+. Fig. S25: COSY of c-p6 T6 12+. Fig. S26: Transient 1 H NOE buildup/decay curves for c-p6 T6 12+. Fig. S27: Full 1 H NMR spectra corresponding to main text Fig. 4. S2 S2 S2 S2 S3 S3 S4 S4 S4 S4 S5 S5 S6 S7 S8 S9 S9 S10 S10 S11 S12 S13 S14 S15 S16 S17 S17 S18 S18 S19 S19 S20 S21 S22 WWW.NATURE.COM/NATURE 1
Supplementary Tables Table S1: Kinetic parameters for porphyrin torsional rotation in c-p6 6+ and c-p6 12+ from 1 H EXSY measurements (500 MHz, CD 2 Cl 2, 213 K). k 213 K (s 1 ) G 213 K (kj mol 1 ) k chem,tc (s 1 ) T c (K) c-p6 6+ 3.45 ± 0.86 49.48 ± 0.44 4154 282 ± 2 c-p6 12+ 172 ± 43 42.56 ± 0.44 1644 234 ± 2 Table S2: Calculated (NICS, ppm) and experimental ( δ, ppm) parameters for the description of aromaticity in different oxidation states of c-p6 (calculations were performed on a c-p6 model). Negative NICS/ δ values correspond to aromaticity, and positive NICS/ δ values to antiaromaticity. The NICS(0) values were calculated at the centre of the ring. The NICS and magnetic susceptibility for the dication were calculated using unrestricted DFT. 0+ 2+ 4+ 6+ 12+ n π e 84 82 80 78 72 Hückel classification 4n π 4n + 2 π 4n π 4n + 2 π 4n π NICS(0) zz (ppm) 1 10 304 41 1 NICS(0) iso (ppm) 1 5 101 13 1 χ mol cm 3 mol 1 (cgs) 2.0 10 3 4.2 10 3 6.8 10 2 1.0 10 2 1.1 10 4 δ oʹ,o (ppm) 0.26 1.87 0.74 δ THSʹ,THS (ppm) 0.14 3.45 0.70 0.18 Table S3: 1 H and 13 C NMR chemical shifts for c-p6 T6, c-p6 T6 4+, c-p6 T6 6+ and c-p6 T6 12+. THS CH 3 refers to the terminal methyl in the hexyl chain of the trihexylsilyl group (determined by multiplicity edited HSQC), and THS CH 2 refers to the methylene proximal (α) to the silicon atom, determined by chemical shift. The inner (ʹ) and outer THS manifolds could be readily distinguished by COSY, TOCSY and NOESY. All chemical shifts are given in ppm. 1 H Neutral 4+ 6+ 12+ 13 C 1 H α 2.41 143.4 5.71 145.9 11.31 151.0 β 4.99 119.9 5.27 8.83 125.6 γ 5.45 124.3 ~5.17 7.94 126.3 δ 5.56 131.2 ~5.17 7.73 131.8 a 9.56 130.6 6.52 128.2 6.05 133.6 b 8.75 133.3 5.99 133.4 5.77 136.5 o 8.06 141.6 7.78 7.31 128.2 oʹ 8.32 140.8 5.91 6.57 134.4 p 8.02 139.9 7.92 7.58 144.6 THS CH 3 0.77 14.4 0.69 13.9 0.84 14.2 0.83 13.7 THSʹ CH 3 0.91 14.4 4.14 17.3 0.14 13.6 0.65 14.1 THS CH 2 0.92 13.0 0.80 11.7 0.73 11.6 0.75 ~13 THSʹ CH 2 0.92 13.0 4.73 14.9 0 10.8 0.59 ~13 δ oʹ,o 0.26 0.8 1.87 0.74 6.2 δ THSʹ,THS CH3 0.14 0 3.45 3.4 0.70 0.6 0.18 0.4 δ THSʹ,THS CH2 0 0 3.93 3.2 0.73 0.8 0.16 ~0 13 C 1 H 13 C 1 H 13 C WWW.NATURE.COM/NATURE 2
Table S4: Chemical shift differences ( δ X+ = δ T6, free δ T6 in [c-p6 T6]X+ ) for the template protons (α, β, γ and δ) in c-p6 T6, c-p6 T6 6+ and c-p6 T6 12+, vs. unbound template (T6, 400 MHz, CDCl 3 ). All values are given in ppm. T6 δ 0 δ 6+ δ 12+ α 8.54 6.13 2.83 2.77 β 7.33 2.34 2.06 1.50 γ 7.24 1.79 2.07 0.70 δ 7.02 1.46 1.85 0.71 Table S5: NICS(0) iso and (in brackets) NICS(0) zz values (ppm) for c-p6 in different oxidation states, with different DFT functionals. The 6-31G* basis set was used throughout. 0+ 2+ 4+ 6+ 12+ B3LYP//B3LYP 1 (1) 5 ( 10) 101 (304) 13 ( 41) 1 (1) B3LYP//B3LYP-D3 1 (1) 5 ( 9) 106 (320) 13 ( 41) 1 (1) M06-2X//M06-2X 2 (1) n.d. 3 (12) 15 ( 45) 0 (1) ωb97x//ωb97x-d 2 (1) n.d. 0 (1) 16 ( 46) 0 (1) WWW.NATURE.COM/NATURE 3
Supplementary Figures Fig. S1: Chemical structures of oxidants used in this study. Abbreviations are expanded in the text. The potentials underneath each structure refer to the E red for the first reduction of each oxidant. Fig. S2: Fit of 1 H EXSY data (500 MHz, CD 2 Cl 2, 213 K) for oʹ/o exchange in c-p6 6+ as a function of t mix. Fig. S3: Fit of 1 H EXSY data (500 MHz, CD 2 Cl 2, 213 K) for oʹ/o exchange in c-p6 12+ as a function of t mix. A normalisation factor was used in this fit, equal to 0.84. WWW.NATURE.COM/NATURE 4
Fig S4: (a) Experimental magnetic susceptibility during an NMR titration (243 K, 470 MHz ( 19 F)) of DIBAHA F into c-p6 T6 in CD 2 Cl 2 (blue diamonds). The molar susceptibility was calculated based on the approximate concentration of c-p6 T6. The concentration of oxidant was corrected by a factor of 1.3 to account for error in the concentrations of oxidant and porphyrin. The red points show the DFT (B3LYP/6-31G*) calculated magnetic susceptibility. (b) A 19 F (470 MHz) NMR spectrum showing the measurement of ν, and the corresponding 1 H (500 MHz) spectrum (inset); these spectra correspond to the third data point (~4 eq. oxidant) in (a). Fig. S5: NMR assignment labels used for (a) linear oligomers and (b) c-p6 T6. WWW.NATURE.COM/NATURE 5
Fig. S6: Representations of c-p6 describing the xy, xz and yz planes in which NICS grids have been calculated. WWW.NATURE.COM/NATURE 6
Fig. S7: NICS zz grids for c-p6 6+ in (a) the xz plane and (b) the yz plane of the molecule. In (a), the view bisects a butadiyne and in (b) the view bisects a porphyrin. (c e) show NICS(z) scans along the z axis of the molecule (see Figure S6). The fitting lines are described below. Level of theory: B3LYP/6-31G*. The calculated NICS(z) values along the z axis of the molecule (Fig. S7 c e) fit well to a cubic polynomial: Where a, b and c are defined by fitting as: oxidation states a b c (Anti)aromatic 2+, 4+, 6+ 4.50 10 2 9.46 10 1 1.10 10 1 Non-aromatic 0, 12+ 1.13 10 1 1.96 1.30 10 1 WWW.NATURE.COM/NATURE 7
Fig. S8: (a-d) NICS(0) iso grids for neutral, 4+, 6+ and 12+ c-p6. (e h): corresponding NICS(0) zz grids. Level of theory B3LYP/6-31G*. WWW.NATURE.COM/NATURE 8
Fig. S9: ACID plots, viewing the molecule along the z axis, for an applied magnetic field along the +z axis, for (a) c-p6, (b) c-p6 4+ (c) c-p6 6+ and (d) c-p6 12+. (e h) show the corresponding views along the y axis. The ACID isosurface corresponds to an isovalue of 0.06 a.u. Fig. S10: 1 H NMR spectra (500 MHz, CD 2 Cl 2 ) of the 2N+ oxidation states of c-p6, c-p8 T8, c-p10, c-p11 and c-p12, generated by oxidation with excess DIBAHA F. WWW.NATURE.COM/NATURE 9
Fig. S11: 1 H NMR (500 MHz, CD 2 Cl 2 ) of l-p1, l-p2 and l-p4 in their diamagnetic neutral, N+ and 2N+ oxidation states (excluding paramagnetic l-p1 + ). Labels are described in SI Fig. S5a. Fig. S12: Square wave voltammetry of l-p1 (blue), l-p2 (red) and c-p6 T6 (orange), in CH 2 Cl 2 (0.1 M Bu 4 NPF 6 ). The abscissa (current) is normalised to the height of the highest oxidation peak (~ 1 V). WWW.NATURE.COM/NATURE 10
Fig. S13: Thin layer spectroelectrochemistry of c-p6 T6 in CH 2 Cl 2 (0.1 M Bu 4 NPF 6 ) in the NIR (a) and IR (b) regions. (c) and (d) show the corresponding cyclic voltammograms to (a) and (b). In part (e), selected spectra corresponding, approximately, to monocation (0.63 V), an intermediate cation (0.81 V) and the hexacation (1.15 V) are presented. WWW.NATURE.COM/NATURE 11
Fig. S14: Frontier orbitals of l-p2 in its neutral, 2+ and 4+ oxidation states. A truncated model of l-p2 was used, with aryl sidegroups and terminal trialkylsilyl alkyne protecting groups truncated to H (overall D 2h symmetry). Level of theory: B3LYP/6-31G*. WWW.NATURE.COM/NATURE 12
Fig. S15: Comparison of 1 H NMR spectra (500 MHz, 223 K, CD 2 Cl 2 ) of template-free c-p6 in its neutral, 6+ and 12+ oxidation states. The 6+ oxidation state was generated by oxidation with excess Thn, and the 12+ oxidation state was generated by oxidation with excess DIBAHA F. WWW.NATURE.COM/NATURE 13
Fig. S16: Comparison of 1 H NMR spectra (500 MHz, 223 K, CD 2 Cl 2 ) of c-p6 in its 6+ oxidation state, with (a) and without (b) template. (a) was generated by oxidation with excess Thn; (b) during titration with AgSbF 6 /I 2. WWW.NATURE.COM/NATURE 14
Fig. S17: VT 1 H NMR (500 MHz, CD 2 Cl 2 ) of c-p6 6+, generated by oxidation with excess Thn. WWW.NATURE.COM/NATURE 15
Fig. S18: VT 1 H NMR (500 MHz, CD 2 Cl 2 ) of c-p6 12+, generated by oxidation with excess DIBAHA F. WWW.NATURE.COM/NATURE 16
Fig. S19: NOESY of c-p6 T6 4+ (500 MHz, 223 K). t mix = 250 ms. This sample was prepared by titration with DIBAHA F. Fig. S20: NOESY of c-p6 T6 6+ (500 MHz, 223 K). t mix = 250 ms. This sample was prepared by titration with AgSbF 6 /I 2. WWW.NATURE.COM/NATURE 17
Fig. S21: NOESY of c-p6 T6 12+ (500 MHz, 223 K). t mix = 200 ms. This sample was prepared by oxidation with excess DIBAHA F. Fig. S22: TOCSY (t mix = 60 ms) of c-p6 T6 4+ (500 MHz, 223 K), using the MLEV17 sequence during the TOCSY mixing time. This sample was prepared by titration with DIBAHA F. WWW.NATURE.COM/NATURE 18
Fig. S23: Expanded COSY of c-p6 T6 6+ (500 MHz, 223 K). This sample was prepared by titration with AgSbF 6 /I 2. Fig. S24: Expanded COSY of c-p6 T6 6+ AgSbF 6 /I 2. (500 MHz, 223 K). This sample was prepared by titration with WWW.NATURE.COM/NATURE 19
Fig. S25: COSY of c-p6 T6 12+ (500 MHz, 213 K). This sample was prepared by oxidation with excess DIBAHA F. WWW.NATURE.COM/NATURE 20
Fig. S26: Transient 1 H NOE (500 MHz, CD 2 Cl 2, 223 K) buildup/decay curves for c-p6 T6 12+, with NOE transfer following selective excitation (t mix = d8) of the template α proton. The sample was prepared by oxidation with excess DIBAHA F. WWW.NATURE.COM/NATURE 21
Fig. S27: Full 1 H NMR spectra (500 MHz) of (a) neutral c-p6 T6 (298 K); (b) c-p6 T6 4+ generated during titration with DIBAHA F, 223 K; (c) c-p6 T6 6+ generated during titration with AgSbF 6 /I 2, 223 K; (d) c-p6 T6 12+ generated by oxidation with excess DIBAHA F, 223 K. (cf. expanded extract in Fig. 4, main text). WWW.NATURE.COM/NATURE 22