Supporting Information

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1 Supporting Information Dynamic Extension-Contraction Motion in Supramolecular Springs Ho-Joong Kim, Eunji Lee, Hye-seo Park, and Myongsoo Lee* Center for Supramolecular ano-assembly and Department of Chemistry, Yonsei University, Seoul , Korea * To whom all correspondence should be addressed. Fax ; Tel ; mslee@yonsei.ac.kr S1

2 Experimental Section Materials. ah (60%), and p-toluenesulfonyl chloride (98%) from TCI and Tokyo Kasei were used as received. 3-Ethynylpyridine (98%) and 3-pyridylboronic acid from Aldrich were used as received. Unless otherwise indicated, all starting materials were obtained from commercial suppliers (Aldrich, Lancaster, and TCI, etc.) and were used without purification. Methylene choride, and ethyl acetate were distilled before use. Visualization was accomplished with UV light and iodine vapor. Flash chromatography was carried out with Silica Gel 60 ( mesh) from EM Science. Dry triethylamine was obtained by vacuum transfer from calcium hydride. Dry THF was obtained by vacuum transfer from sodium and benzophenone. Techniques. 1 H-MR spectra were recorded from CDCl 3 and D 2 solutions on a Bruker AM 250 and Bruker AM 400 spectrometer. 2-D RESY MR experiments were performed with D 2 solutions on a Bruker Advance DRX 400 MR spectrometer. The purity of the products was checked by thin layer chromatography (TLC; Merck, silica gel 60). Microanalyses were performed with a Perkin Elmer 240 elemental analyzer at rganic Research Center, Sogang university. MALDI-TF mass spectra were performed on Perceptive Biosystems Voyager-DE STR using a 2,5-dihydroxy benzoic acid matrix. Dynamic light scattering (DLS) and static light scattering (SLS) measurements were performed using an ALV/CGS-3 Compact Goniometer System with ALV-5000 & 60X0 software. SLS experiments were performed over a scattering angular range 30 to 120 o at the sample concentration 0.05 to 0.1 wt%. The molecular weights of the samples were obtained by Berry plot of the SLS intensity. The specific refractive index increments, dn/dc, in 0.05 to 0.1 wt% aqueous solution were determined as and ml/g for C 1 and C 2, respectively, by differential refractometry. The UV/vis spectra and transmittance were obtained from a Shimadzu UV-1650PC spectrometer. The fluorescence spectra were obtained from a Hitachi F-4500 fluorescence spectrometer. Circular Dichroism (CD) spectra were obtained using Jasco J- 810 spectropolarimeter. The transmission electron microscope (TEM) was performed at 120 kv using JEL-JEM The diameters of cylinders were obtained from 80 cylinders observed by TEM. Compounds were synthesized according to the procedure described scheme 1 and then purified by silica gel column chromatography and prep. HPLC (Japan Analytical Instrument). Molecular modeling and mechanical calculations were computated with Materials Studio Modeling 4.0 (Accelrys Inc.) software. S2

3 H H Ts 4 Br Br Br Br Br Br (H) 2 B ATf - CF Ag + 3 S 3 n 5 L 1 C 1 AgTf CF 3 S 3 - Ag + n L 2 C 2 Scheme 1. A general outline of the synthetic procedure. Compound 4 was synthesized according to the same procedures described previously (Ref. 5 in the text). Synthesis of compound 2 : yield 83 %. 1 (2 g, 9.6 mmol), Br 2 (6.1 g, 38.4 mmol), and benzoyl peroxide (100 mg) were added to nitrobenzene (30 ml). The mixture was exposed to the tungsten lamp for 1 hour and then stirred at 60 o C for 2 hours. n cooling to room temperature, clusters of brown crystals were prepared by filtration, washed with alcohol and dried (2.9 g). m.p. 265~290 o C 1 H-MR (250 MHz, CDCl 3, δ, ppm) δ 8.12 (d, 2H, Ar-H), 8.07 (d, 2H, Ar-H), (dd, 2H, Ar-H). Synthesis of compound 3 : yield 95%. 2 (1g, 2.73 mmol) and a 2 S 2 4 (1.87g, 10.9 mmol) were dissolved into a mixture of THF (100 ml) and H 2 (70 ml). The mixture was stirred for 6 hours, and then extracted with THF. The crude product was dried over anhydrous magnesium sulfate, and filtered g. 1 H-MR (250 MHz, DMS, δ, ppm) δ 9.27 (s, 2H, ArH), 8.99 (s, 2H, Ar-H), 8.08 (d, 2H, Ar-H), 7.75 (d, 2H, Ar-H). S3

4 Synthesis of compound 5 : yield 73 %. 3 (772 mg, 2.10 mmol), 5 (2.8 g, 4.83 mmol), and K 2 C 3 (2.9 g, 21.0 mmol) were dissolved in DMF (25 ml). The mixture was heated at reflux for 18 hours and then coolded to room temperature. Solvent was distilled and the resulting mixture was poured into water and extracted with methylene chloride. The methylene chloride solution was washed with water dried over anhydrous magnesium sulfate, and filtered. The crude products were purified by column chromatography (silica gel, MeH : ethyl acetate = 1 : 20) to yield 2.2 g of yellow oil. 1 H-MR (250 MHz, CDCl 3, δ, ppm) δ 8.62 (s, 2H, Ar-H), 8.12 (d, 2H, Ar-H), 8.08 (d, 2H, Ar-H), 7.67 (d, 2H, Ar-H), 4.20 (t, 4H, CCH 2 ), (m, 62H, CH 2 and CH 3 ), 2.45 (m, 2H, CH(CH 2 ) 3 ), 1.13 (dd, 12H, CHCH 3 ). Synthesis of compound L 1 : yield 91 %. 5 (310 mg, mmol), 4-pyridyl boronic acid (129 mg, 1.05 mmol), and Pd(PPh 3 ) 4 (116 mg, 0.1 mmol) were added to a mixture of 1,4-dioxane (10 ml) and 2M a 2 C 3 aqueous solution (7 ml). The mixture was degassed and then refluxed for 24 hours. Solvent was removed in a rotatory evaporator and the resulting mixture was poured into water and extracted with methylene chloride. The methylene chloride solution was washed with water dried over anhydrous magnesium sulfate, and filtered. The crude products were purified by column chromatography (silica gel, MeH : ethyl acetate = 1 : 8) to yield 270 mg of yellow oil. 1 H-MR (250 MHz, CDCl 3, δ, ppm) ) δ 8.91 (s, 2H, Ar-H), 8.75 (d, 4H, Py-H α ), 8.40 (d, 2H, Ar-H), 7.90 (d, 2H, Ar-H), 7.75 (d, 4H, Py-H β ), 4.28 (t, 4H, CCH 2 ), (m, 62H, CH 2 and CH 3 ), 2.47 (m, 2H, CH(CH 2 ) 3 ), 1.16 (dd, 12H, CHCH 3 ). Anal. Calcd for C 64 H : C, 65.06; H, 8.19;, Found C, 65.01; H, 8.30;, MALDI- TF-MS m/z (M+H) Synthesis of compound L 2 : yield 90 %. 5 (310 mg, mmol), 4-ethynylpyridine-hydrochloride (181 mg, 1.31 mmol), Pd(PPh 3 ) 4 (116 mg, 0.1 mmol), CuI (19 mg, 0.1 mmol) and K 2 C 3 (360 mg, 2.62 mmol) were added to a mixture of DME (10 ml) and H 2 (7 ml). The mixture was degassed and then stirred at 60 o C for 24 hours. Solvent was removed in a rotatory evaporator and the resulting mixture was poured into water and extracted with methylene chloride. The methylene chloride solution was washed with water dried over anhydrous magnesium sulfate, and filtered. The crude products were purified by column chromatography (silica gel, MeH : ethyl acetate = 1 : 8) to yield 290 mg of a yellow oil. 1 H-MR (250 MHz, CDCl 3, δ, ppm) ) δ 8.84 (s, 2H, Ar-H), 8.65 (d, 4H, Py-H α ), 8.27 (d, 2H, Ar-H), 7.75 (d, 2H, Ar-H), 7.47 (d, 4H, Py-H β ), 4.26 (t, 4H, CCH 2 ), (m, 62H, CH 2 and CH 3 ), 2.46 (m, 2H, CH(CH 2 ) 3 ), 1.14 (dd, 12H, CHCH 3 ). Anal. Calcd for C 68 H : C, 66.43; H, 7.87;, Found C, 66.08; H, 7.93;, MALDI-TF-MS m/z (M+H) Complexation of L 1 and L 2 with AgTriflate : C 1 and C 2 were prepared using the same procedure. A representative example is described for C 1. L 1 (19.4 mg, mmol) and AgTf (4.23 mg, mmol) were dissolved in dry EtH solvent (10 ml) and stir under 2 for 3 hours at and the solvent was then removed in a rotary evaporator to yield dimely yellow solid of C 1. C 1 : Anal. Calcd for S4

5 C 65 H 96 AgF S: C, 54.28; H, 6.73;, Found C, 54.08; H, 6.90;, MALDI-TF-MS m/z (M+Ag) C 2 : Anal. Calcd for C 69 H 96 AgF S: C, 55.75; H, 6.51;, Found C, 55.12; H, 6.63;, MALDI-TF-MS m/z (M+Ag) SAXS measurements: The small-angle X-ray scattering (SAXS) measurements were performed in transmission mode with synchrotron radiation at the 4C1 X-ray beam line at Pohang Accelerator Laboratory, Korea. Samples of 0.1 wt% aqueous solution of C 2 were located in sample cell between the mica window (T mica > 85 %), which was done to prevent the water from evaporating during SAXS measurement. The incident beam intensity, with a wavelength of 1.608Å, was monitored using an ionization chamber to correct minor decreases in the primary beam intensity. The scattered X-rays were collected during 100 seconds using a two-dimensional CCD (Mar USA, Inc. CCD165). The sample to detector distance was 1 meter which allowed the SAXS data to be obtained in a q range between 0.6 and A beam path was maintained under a vacuum to reduce air scattering, and the measured intensity was corrected for background scatterings (sample cell and water) and the noises of detector. The measured SAXS intensity was analyzed with the GIFT program, which was developed by Glatter. The scattered intensity from aqueous solution of C 2 was best fitted by cylinder mode of GIFT program with dimension in agreement the diameter observed by TEM. Computation : Simulations were conducted with Materials Studio Modeling 4.0 (Accelrys Inc.) software according to the following procedure. First, a coordination polymer consisting of 14 ligands and AgTfs was built using the MS Visualizer. The potential energy of helical polymer was then minimized until rootmean square derivative 1.0 (kcal/mo)/å or less. The constant temperature and density condition (VT ensemble) was performed on the minimized structure. The structural energy minimization of a coordination polymer was carried out for ps at 298 K, a time step of ps and number of steps of The interatomic interactons were modeled with the CMPASS force field. FRET (fluorescence resonance energy transfer) : To intercalation the perylene within the extended helical pitch, C 3 (1 wt% aqueous solution) added to 5 equiv perylene in 5 ml vial, and then the mixture was treated by ultrasonication for 30 min at LCST. After this time, the solution turned orange, indicative of intercalation of dyes. As shown in Figure S27a, the emission of the polymer showed a significant overlap with the absorption of the perylene dye. Furthermore, the dye showed minimum absorption at the polymer absorption peak, thus minimizing the direct excitation of the perylene. Consequently, we have selected perylene dye for efficient FRET experiments with the C 3. As shown in Figure S28, the fluorescence spectra of C 3 (1 wt%) showed an emission corresponding to cisoid helical folding when excited at 280 (Ref 5), however, excitation of C 3 at 280 in the present of 5 equiv of perylene at 40 o C showed significant fluorescence quenching of the polymer emission (λ max = 400 ) with the S5

6 concomitant formation of the emission between 450 and 600 corresponding to the perylene, indicating the occurrence of FRET from the intercalation of the perylene within the extended aromatic stacking. While cooling to from 40 o C to in the presence of perylene, the emission of perylene showed to be reversibly reduced, indicating that subsequently aromatic units of helix and perylene dye molecules undergo close π-π stacking, resulting in entrapping the perylene into ordered structures, at below LCST. However, preparing the intercalation at below LCST, there is no FRET (Figure S27b), suggesting that there is no apparent intercalation of the dye molecule. S6

7 4700 Reflector Spec #1[BP = , 44562] % Intensity 100 [L H] [L 1 + a] [L 1 + Ag] Mass (m/z) E+4 Figure S1. MALDI-TF mass spectrum of compound C 1. % Intensity Reflector Spec #1[BP = , 31136] [L 2 + H] + [L 2 + Ag] [L 2 + a] E+ Figure S2. MALDI-TF mass spectrum of compound C 2. L 1 L 2 C 1 C Figure S3. Fluorescence spectra of L 1 and C 1 (λ max = 270 ), and L 2 and C 2 (λ max = 280 ), in aqueous solution (0.1 wt %) at room temperature. S7

8 D app x (cm 2 s -1 ) D app x (cm 2 s -1 ) q 2 x (cm -2 ) q 2 x (cm -2 ) Figure S4. Angular dependence of the apparent diffusion coefficient for C 1 and C 2 in aqueous solution (0.1 wt %) at room temperature Iq 2 x (Hz -1 ) q x 10-7 ( -1 ) Iq 2 x (Hz -1 ) q x 10-7 ( -1 ) Figure S5. Kratky plots and linear fit of C 1 and C 2 in aqueous solution (0.1 wt %) at room temperature. 100 Transmittance (%) C 2 C Temperature ( o C) Figure S6. Transmittance of C 1 and C 2 in aqueous solution (0.1 wt%) measured at 500 wavelength. S8

9 30 o C 35 o C 40 o C 45 o C ppm Figure S7. 1 H MR spectra of aromatic region of C 2 (400MHz) in D 2 (0.05 wt%) with various temperatures. 30 o C 35 o C 40 o C 45 o C 50 o C ppm ppm Figure S8. 1 H MR spectra of aliphatic region of C 2 (400MHz) in D 2 (0.05 wt%) with various temperatures. Intensity (a.u.) Intensity (a.u.) Figure S9. TEM images of C 1 (0.01 wt %) with negative staining, prepared at 25 and 50 o C with density profiles inset. The diameters of the elementary fibrils were measured to be 6±0.4 and 5.2±0.5, at 25 and 50 o C, respectively. This result was obtained from 80 cylinders observed by TEM. S9

10 Figure S10. TEM images of C 2 (0.001 wt%) with negative staining, prepared at 25 and 50 o C. This result was obtained from 80 cylinders observed by TEM. 50 o C Figure S11. UV/vis spectra of C 1 in aqueous solution (0.1 wt%) with temperature variation. 50 o C Figure S12. Fluorescence spectra of C 1 in aqueous solution (0.1 wt%, excited at 270 ) with temperature variation. S10

11 R H () R H () Figure S13. DLS results at the scattering angle 90 o C of C 1 and C 2 in aqueous solution (0.1 wt%) at room temperature.?10-4 sqrt(kc/r), Kc/R in mol/g 7.0 Samplename needed (q 2 + Kc) x µm 2 x 10 3 Figure S14. Berry plot of C 1 in aqueous solution, obtained over a scattering angular range 30 to 120 o and a concentration range of 0.05 to 0.1 wt% at. This plot shows M w to be g/mol.?10-5 sqrt(kc/r), Kc/R in mol/g 80.0 Samplename needed (q 2 + Kc) x µm 2 x 10 3 Figure S15. Berry plot of C 2 in aqueous solution, obtained over a scattering angular range 30 to 120 o and a concentration range of 0.05 to 0.1 wt% at. This plot shows M w to be g/mol. S11

12 Log intensity (a. u.) q ( -1 ) Figure S16. The SAXS profile of C 2 in aqueous solution (0.1 wt%) plotted against q (=4πsinθ/λ) Top view Side view T<LCST (d = 0.34 ) T>LCST (d = 0.48 ) Figure S17. Space-filling models of hydrated helix (left) and dehydrated helix (right) by molecular modeling of C 2. Energy minimization of the helix suggests that helical conformation consisting of 3.5 ligands per a turn. The diameters of cylinders and aromatic core are consistent with SAXS and TEM data. Counter-anions are omitted for clarify. d = aromatic stacking distance. S12

13 V hyd = V dehyd A hyd * L hyd = A dehyd * L dehyd V = volume of helix consisting of 14 ligands A = cross-sectional area of helix L = length of helix consisting of 14 ligands hydrated helix (14 ligands) dehydrated helix (14 ligands) outer diameter aromatic core diameter aromatic stacking distance dimension below LCST dimension above LCST 6.5 [a,b,c] 5.5 [a,b] 2.3 [b,c] 2.0 [b,d] 0.34 [b] 0.48 [b,d] Figure S18. Schematic representation and equations for volumetric calculation with helix of C 2 consisting of 14 ligands. Calculated numerical values of the helix (C 2 ). [a]:determined by TEM, [b] : by molecular modeling, [c] : by SAXS, and [d] : by volumetric calculation. 50 o C 40 o C R H () R H () Figure S19. DLS results at the scattering angle 90 o C of C 1 and C 2 in aqueous solution (0.1 wt%) with temperature variation. S13

14 50 o C 40 o C Figure S20. UV/vis spectra of C 1 and C 2 in aqueous solution (0.03 wt%) with temperature variation. 50 o C 40 o C Figure S21. Fluorescence spectra of C 1 and C 2 in aqueous solution (0.03 wt%, excited at 270 and 280, respectively) with temperature variation ppm 50 o C ppm ppm Figure S22. 1 H MR spectra of aromatic regions of C 1 (400MHz) in D 2 (0.05 wt%) with temperature variation. S14

15 Figure S23. Fluorescence spectra of C 1 at (black), at 50 o C (red) and C 1 after the addition of 5 equiv 4-boromonitrobenzene at (green), at 50 o C (blue), excited at 270 (0.1 wt% ). 100 Transmittance (%) Temperature ( o C) Figure S24. Transmittance of C 3 in aqueous solution (0.1 wt%) measured at 500 wavelength. (c) 40 o C 40 o C Figure S25. 1 H MR spectra of aromatic regions of C 3 (400MHz) in D 2 (1 wt%) with temperature variation. UV/vis spectra of C 3 in aqueous solution (0.1 wt%) and (c) fluorescence spectra of C 3 in aqueous solution (1 wt%, excited at 280 ) with temperature variation. S15

16 (c) (d) H1-H5 H1-H5 (c) (e) H3 H2 H4 H6 H1 H1 H5 LCST H3 H2 H4 H6 H1 H1 H5 Figure S26. RESY spectra of C 3 (0.5 wt% in D 2 ) at, and at 40 o C. (c) Molecular structure of C 3 according to RESY spectra. Considering the integrals of E cross-peaks, we can confirm the close proximity of π-π stacking between phenol group and pyridyl group. In RESY spectrum at, in addition to the expected intramolecular E correlations between each aromatic protons and its adjacent protons, other strong correlations are observed, in which H1 of terminal pyridine group of one layer correlates to a H5 of phenol group of other helical layer. At 40 o C, E intensity corresponding to H1-H5 decreases compared to the results at, indicating that aromatic distance is extended. S16

17 Figure S27. UV/vis spectra of C 3 (black, solid line), perylene (red, solid line) and fluorescence spectra of C 3 (black, dashed line), perylene (red, dashed line) at (excited at 280 for C 3 and 400 for perylene). Fluorescence spectra of C 3 (1 wt% aqueous solution) in the absence (black, solid line) and in the presence (red, dashed line) of 5 equiv perylene at (excited at 280 ); The FRET process does not occur, indicating that the perylene dye can not intercalate within aromatic stacking of C 3 at. model-c C 3 model-c C eq + perylene 5eq perylene 40 o C Figure S28. Fluorescence spectra of C 3 (1 wt% aqueous solution) in the absence (blue, dashed line) and in the presence (red, solid line) of 5 equiv perylene at 40 o C (excited at 280 ); The FRET process occurs, indicating that the perylene dye can intercalate within extended aromatic stacking of C 3 at 40 o C. Fluorescence spectra of C 3 (1 wt% aqueous solution) in the presence of 5 equiv perylene with temperature variation (excited at 280 ); This result shows that the intercalated perylene dye remained within contracted aromatic stacking of C 3 at. S17

18 Figure S29. Fluorescence spectra of C 2 at (black), at 40 o C (red) and C 2 after the addition of 5 equiv 4-bromonitrobenzene at (green), at 40 o C (blue), excited at 280 (0.1 wt%); The quenched fluorescence of C 2 shows that 4-bromonitrobenzene can intercalate within the extended aromatic stacking at 40 o C. S18