Compound characterization data — Li et al., 2026

Chenfei Li, K. Wang, W. Wang, Z. Chen, Z. Xu, Y. Cao, Y. Yang, S. Yu, C. Yu, H. Wang, F. Liu, S. Zhang. “Spontaneous polycatenation into linear polycatenanes.” ChemRxiv (2026). https://doi.org/10.26434/chemrxiv.15007480/v1

Tris(2,4-nitrophenyl)-substituted bis(2,4,6-triphenyl-1,3,5-triazine) cage precursor
Identifier	P1
¹H NMR (500 MHz, DMSO-d₆)	δ 9.04 (s, 3H), 8.68 (d, J = 8.8 Hz, 12H), 7.41 (d, J = 8.9 Hz, 12H), 5.60 (s, 3H)
¹³C NMR (126 MHz, DMSO-d₆)	δ 170.12, 157.30 (2C overlapping), 156.53, 133.81, 131.74, 131.68, 126.83, 122.55
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₆₀H₃₀N₁₂O₁₈: 1207.18783; Found 1207.18880

Tris(2,4-aminophenyl)-substituted bis(2,4,6-triphenyl-1,3,5-triazine) cage precursor
Identifier	P2
¹H NMR (400 MHz, DMSO-d₆)	δ 8.61 (d, J = 8.5 Hz, 12H), 7.39 (d, J = 8.5 Hz, 12H), 6.63 (s, 3H), 5.83 (s, 3H)
¹³C NMR (151 MHz, DMSO-d₆)	δ 169.96, 163.04, 162.36, 158.06, 132.17, 130.87, 103.77
HRMS (FT-ICR)	m/z: [M+Na]⁺ Calcd for C₆₀H₄₂N₁₂O₆: 1049.324248; Found 1049.552221

(5-Bromo-3′,5′-di-tert-butyl-[1,1′-biphenyl]-3-yl)methanol
Identifier	P3
¹H NMR (400 MHz, CDCl₃)	δ 7.81 (s, 1H), 7.65 (s, 2H), 7.61 (s, 1H), 7.56 (s, 2H, overlapping signals), 4.82 (s, 2H), 3.55 (s, 1H), 1.56 (s, 18H)
¹³C NMR (126 MHz, CDCl₃)	δ 151.50, 144.90, 143.48, 139.33, 129.62, 128.36, 124.62, 123.07, 122.21, 121.78, 64.43, 35.15, 31.74
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₂₁H₂₇BrO: 374.12398; Found 374.12484

3-Bromo-5-(bromomethyl)-3′,5′-di-tert-butyl-1,1′-biphenyl
Identifier	P4
¹H NMR (400 MHz, CDCl₃)	δ 7.66 (dd, J = 1.8 Hz, 1H), 7.54 (dd, J = 1.9 Hz, 1H), 7.52 (dd, J = 1.7 Hz, 1H), 7.50 (dd, J = 1.9 Hz, 1H), 7.37 (d, J = 1.8 Hz, 2H), 4.53 (s, 2H), 1.41 (s, 19H)
¹³C NMR (126 MHz, CDCl₃)	δ 151.63, 145.27, 140.11, 138.82, 130.60, 130.52, 126.97, 122.96, 122.45, 121.73, 35.16, 32.33, 31.66
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₂₁H₂₆Br₂: 438.03753; Found 438.03846

2,4,6-Tris(4-((5-bromo-3′,5′-di-tert-butyl-[1,1′-biphenyl]-3-yl)methoxy)phenyl)-1,3,5-triazine
Identifier	P5
¹H NMR (400 MHz, CDCl₃)	δ 9.87 (d, J = 8.9 Hz, 6H), 8.88 (s, 3H), 8.78 (s, 3H), 8.76 (s, 3H), 8.66 (s, 3H), 8.57 (s, 6H), 8.28 (d, J = 8.9 Hz, 6H), 6.34 (s, 6H), 2.57 (s, 54H)
¹³C NMR (126 MHz, CDCl₃)	δ 170.71, 161.99, 151.46, 145.00, 138.95, 130.83, 130.18, 129.59, 125.24, 123.02, 122.24, 121.67, 114.79, 69.35, 35.03, 31.52
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₈₄H₉₀Br₃N₃O₃: 1430.45919; Found 1430.45619

2,4,6-Tris(4-[(3-formyl-3′,5′-di-tert-butyl-[1,1′:3′,1′′-terphenyl]-5-yl)methoxy]phenyl)-1,3,5-triazine
Identifier	P6
¹H NMR (400 MHz, CDCl₃)	δ 10.12 (s, 3H), 8.74 (d, J = 8.9 Hz, 6H), 8.18 (t, J = 1.8 Hz, 3H), 7.93 (ddt, J = 13.1, 7.8, 1.4 Hz, 6H), 7.77 (t, J = 1.7 Hz, 3H), 7.72 (d, J = 1.7 Hz, 3H), 7.70 (t, J = 1.6 Hz, 3H), 7.66 (t, J = 7.6 Hz, 3H), 7.49 (t, J = 1.8 Hz, 3H), 7.46 (d, J = 1.8 Hz, 6H), 7.19 (d, J = 8.9 Hz, 6H), 5.34 (s, 6H), 1.40 (s, 54H)
¹³C NMR (126 MHz, CDCl₃)	δ 192.29, 170.73, 151.41, 142.02, 140.75, 140.14, 133.31, 130.83, 129.63, 129.49, 128.84, 128.52, 126.54, 126.33, 125.10, 121.99, 121.86, 114.84, 35.05, 31.57
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₁₀₅H₁₀₅N₃O₆: 1505.80295; Found 1505.81094

3′-Hydroxy-5-methoxy-[1,1′-biphenyl]-3-carbaldehyde
Identifier	P7
¹H NMR (400 MHz, CDCl₃)	δ 10.04 (s, 1H), 7.68 (dd, J = 1.5 Hz, 1H), 7.41 – 7.38 (m, 2H), 7.35 (t, J = 7.9 Hz, 1H), 7.19 (ddd, J = 7.7, 1.7, 1.0 Hz, 1H), 7.12 (dd, J = 2.5, 1.7 Hz, 1H), 6.91 (ddd, J = 8.1, 2.5, 0.9 Hz, 1H), 5.78 – 5.61 (m, 1H), 3.93 (s, 3H)
¹³C NMR (126 MHz, CDCl₃)	δ 192.62, 160.63, 156.42, 143.28, 141.30, 138.18, 130.35, 122.55, 120.24, 119.62, 115.30, 114.27, 111.35, 55.80
HRMS (FT-ICR)	m/z: [M+H]⁺ Calcd for C₁₄H₁₂O₃: 229.0859; Found 229.0852

1,3,5-Tris[(5-methoxy-3-formyl-[1,1′-biphenyl]-3′-yl)oxy]methylbenzene
Identifier	P8
¹H NMR (400 MHz, CDCl₃)	δ 10.04 (s, 1H), 7.68 (dd, J = 1.5 Hz, 1H), 7.59 (s, 1H), 7.44 – 7.36 (m, 3H), 7.28 – 7.22 (m, 2H), 7.03 (ddd, J = 8.3, 2.5, 1.0 Hz, 1H), 5.22 (s, 2H), 3.93 (s, 3H)
¹H NMR integration reporting qualifier	The integrals were normalized by a factor of 1/3 to account for the C3 symmetry, since each signal arises from three equivalent nuclei
¹³C NMR (126 MHz, CDCl₃)	δ 192.21, 160.67, 159.25, 143.36, 141.25, 138.83, 138.03, 130.25, 126.24, 122.45, 120.18, 120.13, 114.42, 114.12, 111.32, 69.94, 55.82
HRMS (FT-ICR)	m/z: [M+K]⁺ Calcd for C₅₁H₄₂O₉: 837.24604; Found 837.24929

Cage monomer
¹H NMR (400 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 9.08 (s, 2H), 8.60 (d, J = 8.4 Hz, 4H), 8.50 (d, J = 8.3 Hz, 4H), 8.42 (s, 2H), 7.97 (d, J = 7.7 Hz, 2H), 7.88 (s, 2+2H, overlapping signals), 7.84 (d, J = 8.0 Hz, 3H), 7.69 (s, 2H), 7.63 (t, J = 7.8 Hz, 2H), 7.53 (s, 1H), 7.50 (s, 4+2H, overlapping signals), 7.11 (d, J = 8.5 Hz, 4H), 7.07 (d, J = 8.7 Hz, 4H), 5.55 (s, 1H), 5.16 (s, 4H), 1.41 (s, 36H)
¹³C NMR (151 MHz, CDCl₃)	δ 170.56, 170.19, 162.55, 158.45, 151.48, 143.85, 141.40, 141.32, 140.44, 137.51, 136.99, 133.48, 132.89, 130.86, 130.22, 129.46, 129.15, 128.34, 127.77, 127.38, 127.21, 126.64, 122.79, 122.00, 114.51, 35.18, 31.71
HRMS (MALDI-TOF)	m/z: [M]⁺ Calcd for C₂₇₀H₂₄₀N₁₈O₁₂: 3928.881; Found 3928.947

Cage-catenane dimer
¹H NMR (400 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 8.93 (s, 2H), 8.66 (s, 2H), 8.47 (d, J = 8.3 Hz, 4H), 8.31 (s, 2H), 8.23 – 8.14 (m, 6H), 7.86 (d, J = 7.8 Hz, 3H), 7.76 (dd, J = 14.7, 7.2 Hz, 14H), 7.67 (s, 2H), 7.63 – 7.48 (m, 16H), 7.38 (d, J = 21.7 Hz, 20H), 7.28 (s, 3H), 7.21 (s, 4H), 6.94 (d, J = 8.5 Hz, 4H), 6.86 (d, J = 8.3 Hz, 4H), 6.64 (d, J = 8.3 Hz, 4H), 6.38 (d, J = 8.4 Hz, 4H), 5.25 (s, 1H), 5.23 (s, 2H), 5.04 (s, 4H), 4.96 (s, 4H), 1.33 (s, 36H), 1.28 (s, 36H)
¹³C NMR (151 MHz, CDCl₃)	δ 170.51, 168.98, 168.35, 162.51, 161.33, 160.32, 158.16, 151.47, 151.06, 143.82, 141.37, 141.29, 140.45, 140.35, 137.09, 137.07, 136.99, 132.68, 130.78, 130.62, 130.35, 129.42, 129.11, 127.74, 127.22, 126.49, 122.61, 122.00, 114.46, 113.01, 35.18, 35.08, 31.73, 31.71
HRMS (MALDI-TOF)	m/z: [M]⁺ Calcd for C₅₄₀H₄₈₀N₃₆O₂₄: 7857.763; Found 7857.808
Single-crystal XRD, empirical formula	C₂₇₀O₁₂N₁₈H₂₄₀
Single-crystal XRD, formula weight	3928.79 (for one cage unit)
Single-crystal XRD, temperature	296(2) K
Single-crystal XRD, crystal system and space group	Trigonal; P3
Single-crystal XRD, unit cell	a = 35.193(4) Å, b = 35.193(4) Å, c = 40.235(7) Å, α = 90°, β = 90°, γ = 120°
Single-crystal XRD, volume and Z	43157(12) Å³; 4
Single-crystal XRD, calculated density, absorption coefficient, and F(000)	0.605 g/cm³; 0.034 mm⁻¹; 8328.0
Single-crystal XRD, crystal size and radiation	0.15 × 0.1 × 0.1 mm³; synchrotron (λ = 0.68883)
Single-crystal XRD, 2θ range and index ranges	1.624 to 33.398°; −29 ≤ h ≤ 29, −29 ≤ k ≤ 29, −33 ≤ l ≤ 33
Single-crystal XRD, reflections collected and independent reflections	192090; 35049 [Rint = 0.0829, Rsigma = 0.0535]
Single-crystal XRD, data/restraints/parameters and goodness-of-fit on F2	35049/12500/3417; 0.976
Single-crystal XRD, final R indexes [I >= 2σ(I)]	R1 = 0.1030, wR2 = 0.2376
Single-crystal XRD, final R indexes [all data]	R1 = 0.1760, wR2 = 0.2918
Single-crystal XRD, largest difference peak/hole and Flack parameter	0.20/−0.27 e Å⁻³; −1(3)
Single-crystal XRD, CheckCIF	One level-A alert and eleven level-B alerts; the crystal weakly diffracted, the resolution was low, and the data quality was not high enough to obtain high-precision bond lengths
Single-crystal XRD, adjacent-panel centroid-to-centroid distances	Close-contact distances 3.2–3.3 Å; distances between the panels of the outer two cages 7.7–8.2 Å

Cage-catenane trimer
¹H NMR (600 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 9.02 (s, 2H), 8.74 (2 × s, 4H), 8.55 (d, J = 7.8 Hz, 4H), 8.39 (s, 2H), 8.34 – 8.21 (m, 8H), 7.99 – 7.78 (m, 12H), 7.77 – 7.57 (m, 28H), 7.54 – 7.32 (m, 32H), 7.27 (dd, J = 4.3, 1.8 Hz, 1H), 7.05 – 7.00 (m, 4H), 6.93 (d, J = 8.3 Hz, 4H), 6.72 – 6.68 (m, 4H), 6.57 (d, J = 7.7 Hz, 2H), 6.41 (dd, J = 16.5, 8.1 Hz, 10H), 5.32 (s, 3H, sh), 5.07 (br m, 12H), 1.43 – 1.32 (108H)
¹³C NMR (151 MHz, CDCl₃)	δ ¹³C NMR (151 MHz, CDCl₃) δ 171.16, 170.38, 169.58, 169.19, 168.50, 167.17, 167.02, 162.99, 162.37, 161.09, 160.13, 155.70, 150.89, 149.40, 144.23, 142.99, 141.15, 140.70, 140.28, 137.44, 136.50, 136.36, 134.63, 134.04, 131.19, 130.61, 130.20, 129.70, 129.10, 127.89, 126.45, 126.02, 125.05, 124.74, 123.02, 121.85, 121.00, 118.59, 115.14, 111.25, 103.76, 70.63, 70.07, 53.44, 35.44, 35.04, 31.57
MS (MALDI-TOF)	m/z: [M+H]⁺ Calcd for C₈₁₀H₇₂₁N₅₄O₃₆: 11788.0; Found 11790.1

Cage-catenane tetramer
¹H NMR (600 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 9.02 (s, 2H), 8.72 (2 × s, 6H), 8.56 (d, J = 7.7 Hz, 5H), 8.39 (s, 2H), 8.26 (s, 9H), 7.95 (d, J = 8.4 Hz, 2H), 7.91 – 7.78 (m, 11H), 7.66 (m, 56H), 7.53 – 7.31 (m, 38H), 7.27 – 7.24 (m, 2H), 7.03 (d, J = 8.1 Hz, 4H), 6.93 (d, J = 7.7 Hz, 4H), 6.73 – 6.68 (m, 4H), 6.55 (t, J = 8.8 Hz, 4H), 6.44 – 6.30 (m, 8H), 5.22 – 4.85 (m, 20H), 1.44 – 1.33 (m, 144H)
¹³C NMR (151 MHz, CDCl₃)	δ 171.16, 170.38, 169.58, 169.19, 168.50, 167.17, 167.02, 162.99, 162.37, 161.09, 160.13, 155.70, 150.89, 149.40, 144.23, 142.99, 141.15, 140.70, 140.28, 137.44, 136.50, 136.36, 134.63, 134.04, 131.19, 130.61, 130.20, 129.70, 129.10, 127.89, 126.45, 126.02, 125.05, 124.74, 123.02, 121.85, 121.00, 118.59, 115.14, 111.25, 103.76, 70.63, 70.07, 53.44, 35.44, 35.04, 31.57
MS (MALDI-TOF)	m/z: [M+H]⁺ Calcd for C₁₀₈₀H₉₆₁N₇₂O₄₈: 15717.0; Found 15716.7

Cage-catenane pentamer
¹H NMR (600 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 8.91 (s, imine CH), 8.64 (s, imine CH), 8.62 – 8.54 (m, imine CH), 8.45 (d, J = 7.6 Hz), 8.28 (s), 8.15 (d, J = 8.7 Hz), 7.84 (d, J = 8.3 Hz), 7.81 – 7.67 (m), 7.65 – 7.21 (m), 7.10 – 7.03 (m), 6.93 (d, J = 8.1 Hz), 6.83 (d, J = 7.5 Hz), 6.60 (d, J = 7.7 Hz), 6.44 (q, J = 7.9, 7.5 Hz), 6.35 – 6.17 (m), 5.66 (s), 5.10 – 4.70 (m), 1.29 – 1.12 (m)
¹³C NMR (151 MHz, CDCl₃)	δ 167.46, 166.45, 160.04, 158.80, 157.02, 151.85, 150.67, 149.84, 141.94, 139.66, 139.21, 135.91, 131.98, 131.28, 129.17, 127.74, 126.79, 126.71, 126.70, 126.54, 125.73, 125.30, 124.55, 120.81, 120.54, 112.09, 106.59, 52.40, 30.53, 29.72, 28.69
HRMS (MALDI-TOF)	m/z: [M]⁺ Calcd for C₁₃₅₀H₁₂₀₀N₉₀O₆₀: 19644; Found 19653

Cage-catenane hexamer
¹H NMR (600 MHz, CDCl₃; reported integrations correspond to the asymmetric unit)	δ 8.91 (s, imine CH), 8.58 (m, imine CH), 8.45 (d, J = 7.3 Hz), 8.28 (s), 8.15 (s), 7.84 (d, J = 8.3 Hz), 7.80 – 7.67 (m), 7.67 – 7.43 (m), 7.40 (s), 7.36 (d, J = 8.8 Hz), 7.34 – 7.20 (m), 7.15 (d, J = 9.1 Hz), 7.11 – 7.03 (m), 7.01 (s), 6.93 (d, J = 8.1 Hz), 6.83 (d, J = 7.4 Hz), 6.59 (d, J = 7.6 Hz), 6.44 (dt, J = 19.1, 11.9 Hz), 6.36 – 6.17 (m), 5.66 (s), 5.28 (m), 5.08 – 4.95 (m), 4.95 – 4.68 (m), 1.31 – 1.08 (m)
¹³C NMR (151 MHz, CDCl₃)	δ 170.52, 168.02, 166.12, 159.98, 159.57, 159.48, 158.53, 156.07, 154.88, 152.49, 151.32, 150.28, 149.83, 141.93, 140.82, 140.23, 138.83, 138.39, 135.91, 132.60, 131.99, 131.65, 129.24, 128.90, 127.35, 126.40, 125.94, 125.45, 125.34, 125.10, 124.42, 120.54, 112.78, 111.72, 105.31, 104.99, 71.30, 69.37, 67.38, 60.64, 51.72, 48.26, 30.53, 28.69
HRMS (MALDI-TOF)	m/z: [M]⁺ Calcd for C₁₆₂₀H₁₄₄₀N₁₀₈O₇₂: 23573; Found 23585

Phenyl panel cage monomer
¹H NMR (400 MHz, CDCl₃)	δ 8.92 (s, 2H), 7.68 (s, 4H), 7.48 (s, 4H), 7.40 (d, J = 8.0 Hz, 4H), 7.36 (s, 4H), 7.26 (m, 10H), 7.01 (d, J = 7.6 Hz, 4H), 6.96 (s, 3H), 6.91 (d, J = 8.2 Hz, 4H), 6.73 (s, 4H), 5.40 – 5.25 (m, 4H), 5.10 (s, 1H), 5.03 (s, 6H)
¹³C NMR (126 MHz, DMSO-d₆)	δ 173.17, 168.00, 158.13, 157.17, 151.13, 141.47, 137.98, 137.27, 137.06, 134.52, 130.66, 129.52, 127.87, 125.86, 124.99, 120.15, 119.53, 116.82, 116.39, 113.53, 112.86, 68.69, 51.01
HRMS (MALDI-TOF)	m/z: [M+H]⁺ Calcd for C₁₃₂H₉₆N₆O₁₈: 2053.685; Found 2054.078

Cage monomer-to-hexamer series
¹H–¹³C HSQC, monomer and dimer	Full proton and carbon resonance assignment
¹H–¹³C HSQC, trimer to hexamer, aromatic region	The same key proton–carbon correlations were observed; no additional correlations or unexpected coupling patterns were detected aside from changes attributable to integration
¹H–¹³C HSQC (Bruker hsqcetgpsisp2.2, relaxation delay 2 s), monomer to hexamer	The relative intensities of imine cross-peaks assigned to chain-end and interchain environments closely followed the theoretical trend with increasing oligomer length
Quantitative HSQC and ¹H NMR, diagnostic regions	H1_end and H2+3_int were relatively clean with minimal overlap; H2+3_int/H1_end = 4(n − 1) for isolated oligomers with n = 1–6

Phenyl-panel A3/B6 control reaction mixture
GPC	A single narrow peak corresponding to the monomeric cage; no significant amount of polymeric species
GPC number-average molecular weight (Mn)	3,000
GPC weight-average molecular weight (Mw)	3,600
GPC dispersity (Đ)	1.2
GPC degree of polymerization (DPn)	1.5
¹H NMR, crude reaction mixture	Well-resolved aromatic and imine resonances consistent with a discrete monomeric cage as the major product; trace signals possibly assignable to dimeric species; no pronounced peak broadening or baseline elevation characteristic of high-molecular-weight polycatenane species
MALDI–TOF MS, insoluble precipitate	Cage-derived 1mer, 2mer, trace higher oligomeric species, and a broad distribution of A3/B6-derived signals with varying stoichiometric compositions

Crude polycatenane and fractions A–G
GPC–LS, crude polycatenane, number-average molar mass (Mn)	1.07 × 10⁶ g mol⁻¹
GPC–LS, crude polycatenane, weight-average molar mass (Mw)	1.80 × 10⁶ g mol⁻¹
GPC–LS, crude polycatenane, dispersity (Đ)	1.7
GPC–LS, crude polycatenane, DPn and DPw	Approximately 270 and approximately 460
GPC–LS, crude polycatenane, later-eluting signal	A small signal at approximately 22 mL assigned to residual A3 precursor
MALDI–TOF MS, crude polycatenane	A broad series of evenly spaced peaks consistent with successive incorporation of the cage repeating unit; species with n ≥ 26 were observed in the high-mass region
MALDI–TOF MS, crude polycatenane, minor inter-peak signals	Signals assigned to DCTB matrix, doubly charged catenane oligomer ions, hydrated polycatenane-related species, and A3-deficient/B6-containing cage-related species
MALDI–TOF MS, observed m/z against assigned degree of polymerization, zero-intercept linear fit	Slope approximately 4.0 kDa per repeating unit; calculated cage repeating-unit mass approximately 3.9 kDa
GPC–LS, fractions A–E	Molecular weight decreased systematically with increasing retention volume; fraction A contained the highest-molecular-weight population and fractions B–E showed progressively lower DP values
¹H NMR, fractions A–D	Similar characteristic resonances of the polycatenane framework; terminal resonances were intrinsically weak relative to framework signals
¹H NMR, fraction E	Aldehyde-related resonances mainly attributable to residual A3 precursor
¹H NMR, fractions E–G	Characteristic polycatenane-related resonances; fraction E showed aldehyde signals consistent with residual A3 precursor, fraction F showed slightly shifted aldehyde resonances attributed to hydrolysed polycatenane-related species arising from partial imine hydrolysis, and fraction G had very weak, nearly negligible aldehyde signals
MALDI–TOF MS, fraction E	Oligomeric species up to 5mer and minor hydrated species including 1mer + nH2O and 2mer + nH2O
MALDI–TOF MS, fractions F and G	Mainly 1mer with weaker 2mer and 3mer signals; hydrated-species (+H2O) signals were negligible

Fractionated polycatenane with DPn approximately 40
LP-TEM in o-DCB	Chain-like objects adopting bent and continuously varying conformations
LP-TEM apparent widths	Average and median approximately 3.3 nm
SAXS in THF, flexible-cylinder fit (q = 0.05548–0.55793 Å⁻¹)	Contour length fixed at 640.17 Å; radius 13.70 ± 0.10 Å; Kuhn length 160 ± 44 Å; χ2 = 2.55
SAXS cross-sectional diameter	2.74 ± 0.02 nm
SAXS persistence length	8.0 ± 2.2 nm
SAXS normalized fit residuals	Centred around zero without a pronounced systematic trend over most of the fitted q range

Low-DP crude polycatenane and fractions I–VII
GPC–LS, crude sample DPn	16
Quantitative ¹H NMR and GPC–LS, crude sample average number of chain ends per molecule (Nc)	1.97
¹H NMR, fractions I–V, H1_end normalized to 1.00	Relative H2+3_int integral increased systematically from fraction I to V
Quantitative ¹H NMR and GPC–LS, fractions I–V	All Nc values were close to 2
Quantitative ¹H NMR and GPC–LS, asterisk-marked fraction	Nc = 2.03
¹H NMR, fractions VI and VII	Characteristic polycatenane-related resonances; aldehyde signals assigned to residual A3 and aldehyde-bearing species arising from incomplete ring closure and/or partial imine hydrolysis
MALDI–TOF MS, asterisk-marked fraction	Hydrated cage species, hydrated 1mer species, and aldehyde-bearing cage-derived species including 1mer + A3 and 1mer + A3 + B6
MALDI–TOF MS, fraction VI	1mer, hydrated 1mer + nH2O species, 1mer + A3 + 1–3H2O, and 1mer + B6-derived signals

Polycatenane imine-formation reaction mixture
In situ ¹H NMR ([CHO]0 = 0.48 mM; 1,3,5-trimethoxybenzene internal reference; 0–900 min)	The aldehyde signal gradually decreased and reached a plateau
Reversible second-order fit, apparent forward rate constant (kf)	0.035 mM−1 min−1
Reversible second-order fit, apparent reverse rate constant (kr)	0.010 mM−1 min−1
Kinetically derived apparent equilibrium parameter (Kimine = kf/kr)	3.5
Derived ΔGimine at 298 K	−3.1 kJ mol⁻¹

Cage monomer-to-hexamer hosts with A3
Rapid ¹H NMR after mixing, cage host with A3 in CDCl₃/DMSO (2:3, v/v) at 298 K	Free and bound A3 populations were established within the time resolution of the first spectrum and remained essentially unchanged over 25 min
NOESY	Cross-peaks between A3 and aromatic protons lining the host cavity
ROESY (500 ms mixing time)	Two sets of exchange cross-peaks between free guest and host–guest-complex resonances
¹H NMR titration, exchange regime	Distinct free and bound resonances coexisted in the slow-exchange regime
Effective 1:1 cavity-based KHG, monomer	(0.83 ± 0.01) × 10³ M⁻¹
Effective 1:1 cavity-based KHG, dimer	(2.81 ± 0.09) × 10³ M⁻¹
Effective 1:1 cavity-based KHG, trimer	(2.72 ± 0.08) × 10³ M⁻¹
Effective 1:1 cavity-based KHG, tetramer	(2.97 ± 0.11) × 10³ M⁻¹
Effective 1:1 cavity-based KHG, pentamer	(2.83 ± 0.08) × 10³ M⁻¹
Effective 1:1 cavity-based KHG, hexamer	(2.59 ± 0.10) × 10³ M⁻¹
Cage-based KHG and ΔGHG, monomer, titration	1660 M⁻¹; −18.37 kJ mol⁻¹
Cage-based KHG and ΔGHG, higher oligomers, titration	5600 M⁻¹; −21.38 kJ mol⁻¹

Equilibrated polycatenation reaction mixture
Quantitative in situ ¹H NMR integrals	INH2 1.00, IH2O 1048.13, Iref 500.00, IDMSO 337.09, Iref/IDMSO 1.48, ICHO free 67.81, ICHO M HG 2.03, ICHO D+PHG 4.89, Fraction D 0.39, Fraction P 0.61, ICHO DHG 1.93, ICHO PHG 2.96, IM 0.71, ID+P 0.36
Quantitative in situ ¹H NMR concentrations (mM)	cref 34.7, cCHO 36.42, cNH2 0.14, cH2O 54.83, cMfree 0.02, cD+Pfree 0.01, cPfree 0.01, cMHG 0.07, cD+PHG 0.17, cPHG 0.10
In situ ¹H NMR KHG and ΔGHG, monomeric species	1214 M⁻¹; −17.59 kJ mol⁻¹
In situ ¹H NMR KHG and ΔGHG, higher oligomeric species	5765 M⁻¹; −21.45 kJ mol⁻¹
Two-regime model, first catenation event	K2 = 8097 M⁻¹; ΔG2 = −22.30 kJ mol⁻¹
Two-regime model, subsequent propagation	K = 24567 M⁻¹; ΔG = −25.05 kJ mol⁻¹