Supramolecular Helical Assembly of an Achiral Cyanine Dye in an Induced

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1 (Supporting Information) Supramolecular Helical Assembly of an Achiral Cyanine Dye in an Induced Helical Amphiphilic Poly(phenylacetylene) Interior in Water Toyoharu Miyagawa, Miho Yamamoto, Reiko Muraki, Hisanari Onouchi,, and Eiji Yashima *,, Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology (ERATO), apan Science and Technology Agency (ST), 11 Creation Core Nagoya, 66- Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-3, apan. Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, and Venture usiness Laboratory (VL), Nagoya University, Chikusa-ku, Nagoya , apan. 1. Materials and Instruments Materials. Cis-transoidal, stereoregular poly-1 was prepared according to the previously reported method. 1 The number-average molecular weight (M n ) and its distribution (M w /M n ) were and 4.1, respectively, as determined by size exclusion chromatography (SEC) with tetrahydrofuran (THF) containing.1 wt% tetran-butyl ammoniumbromide as the eluent. Cyanine dyes, 3,3 -diethyloxadicarbocyanine iodide (O-5), 3,3 -diethyloxatricarbocyanine iodide (O-7), 1,1,3,3,3,3 - hexamethylindodicarbocyanine iodide (I-5), and 3,3 -diethylthiadicarbocyanine iodide (S-5), were purchased from Acros Organics (Geel, elgium). 3,3 - Diethyloxacarbocyanine iodide (O-3), 1,1 -diethyl-, -dicarbocyanine iodide (Q-5), and L- and D-tryptophan (L- and D-Trp) (purity >98%) were obtained from Aldrich (Milwaukee, WI). (1R,S)-( )- and (1S,R)-(+)-norephedrine ((1R,S)- and (1S,R)-) and anhydrous methanol (water content <.5 vol %) were purchased from Wako Chemicals (Osaka, apan). Instruments. NMR spectra were taken on a Varian VXR-5S (5 MHz for 1 H) spectrometer in D O or CD 3 OD using a solvent residual peak as the internal standards. SEC measurement was performed with a asco PU-158 liquid chromatograph S1

2 equipped with a UV detector (54 nm; asco UV-157). A Tosoh (Tokyo, apan) TSKgel Multipore-H XL -M SEC column (3 cm) was connected, and THF containing.1 wt % tetra-n-butylammonium bromide was used as the eluent at a flow rate of 1. ml/min. The molecular weight calibration curve was obtained with polystyrene standards (Tosoh). The absorption and CD spectra were measured in a.5-, or 1.-mm quartz cell on a asco V-57 spectrophotometer and a asco -75 or -8 spectropolarimeter, respectively. The temperature was controlled with a asco ETC 55T (for absorption measurements) and a asco PTC-43L apparatus (for CD measurements). The ph of the solution was measured with a -1 ph meter (Horiba, apan). pd values were estimated from the reading of ph meter according to the equation pd = ph meter reading +.4 reported by Glasoe et al.. Inclusion Complexation of Cyanine Dyes with Poly-1 in Water Deionized, distilled water was distilled again under nitrogen before use for all experiments. The concentration of poly-1 was calculated on the basis of the monomer units. A typical experimental procedure for the inclusion experiments of cyanine dyes by poly-1 in water is described below. Stock solutions of O-5 (.7 mg, 5.6 μmol) in methanol and poly-1 (. mg, 5.1 μmol) in water were prepared in 5- and 1-mL flasks with stopcocks, respectively. A 116 μl aliquot of the stock solution of O-5 (.13 μmol) was placed into a -ml vessel equipped with a screwcap using a micropipette (Mettler-Toledo GmbH, Switzerland) and the solvent was evaporated by flushing with nitrogen gas. A 5 μl aliquot of the stock solution of poly-1 and water (189 μl) were transferred to the vessel and the resulting mixture was immediately mixed using a vibrator (Iuchi, apan). An eleven μl aqueous.46 M HClO 4 was then added to the vessel. The absorption spectra of the mixture before (neutral) and after the addition of aqueous HClO 4 (acidic) were taken using a.5-mm quartz cell (c and d in Figure ). The solution color gradually changed S

3 from pink to turquoise blue, accompanied by a large red shift in the absorption up to ca. 9 nm due to the -aggregates formation of O-5. The absorption spectra of O-5 in the absence of poly-1 in neutral and acidic water were also measured; O-5 is readily soluble in neutral water, but aggregated in acidic water (ph.1) and then immediately precipitated, so that the absorption spectrum of O-5 in acidic water was measured after filtration (a and b in Figure ). The inclusion experiments of the other cyanine dyes O-3, O-7, I-5, S-5, and Q-5 were also performed in a similar way described above in the absence or presence of poly-1. The changes in the absorption spectra of the cyanine dyes with and without poly-1 in neutral and acidic water are shown in Figure S1. 3. Chiral -Aggregates Formation of O-5 in a Helical Poly-1 Interior The chiral -aggregates of O-5 formed in a one-handed helical poly-1 interior induced by D- and L-Trp, and (1R,S)- and (1S,R)- were prepared in acidic water. A typical experimental procedure is described below. Stock solutions of D- and L-Trp (18 mg,.67 mmol) in aqueous.1 M HClO 4 were prepared in 3-mL flasks with stopcocks, respectively. The mixture of O-5 and poly-1 in neutral water was prepared in the same way as described above and cooled in an ice bath. A 61 μl aliquot of the stock solution of D- or L-Trp and aqueous.46 M HClO 4 (11 μl) were then added in this order to the vessel and the solution was allowed to warm to room temperature for sec, since the absorption intensity at 669 nm of the mixture due to the -aggregate formation of O-5 reached a maximum value during the time period, and gradually decreased with time at room temperature (Figure S5). Although the O-5 aggregates showed almost no ICD in the chromophore region at this stage, extraordinary intense ICDs appeared in the O-5 chromophore regions after annealing the samples at 55 C for 9 (Trp) or 6 sec (), followed by cooling in an ice bath for 6 sec (a and b in Figure 3). The ICD intensity in the O-5 aggregate regions S3

4 was sensitive to the heating temperature and time, and the HClO 4 concentration, and the optimized conditions were determined by screening these parameters; for the effects of the heating temperature and time, and the HClO 4 concentration on the ICD intensities of the chiral -aggregated O-5 in the presence of a helical poly-1 induced by L-Trp and (1R,S)-, see Figures S6 S8. Effect of ph. The chiral -aggregates of O-5 induced by a one-handed helical poly- 1 assisted by D-Trp and (1R,S)- were prepared in acidic water in the same way as described above (a in Figures 4A and 4). To these were added an increasing amount of aqueous NaOH (.5 or N) and the CD and absorption spectra were measured (Figure 4). CD and Absorption Spectral Changes of Chiral -Aggregates of O-5 During the Helix-Sense Inversion of the Template Poly-1. A typical experimental procedure is described below. Stock solutions of O-5 (3. mg, 6. μmol) in methanol, poly-1 (. mg, 5.1 μmol) in water, and D- or L-Trp (18 mg,.67 mmol) in aqueous.1 M HClO 4, were prepared in 5-, 1-, and 3-mL flasks with stopcocks, respectively. A 14 μl aliquot of the stock solution of O-5 (.1 μmol) was placed into a -ml vessel equipped with a screwcap using a micropipette and the solvent was evaporated by flushing with nitrogen gas. A 5 μl aliquot of the stock solution of poly-1 and water (196 μl) were transferred to the vessel and the resulting mixture was immediately mixed using a vibrator and cooled in an ice bath. After a 3 μl aliquot of the stock solution of D-Trp and aqueous.46 M HClO 4 ( μl) were added in this order to the vessel, the solution was allowed to warm to room temperature for sec. The color of the solution became turquoise blue during this procedure. The solution was then heated in a 55 C water bath for 9 sec and then cooled in an ice bath for 1 min. After the initial CD and absorption spectra were measured, a 3 μl aliquot of the stock solution of L-Trp was added to the solution and the absorption and CD spectra were immediately measured. This gave a poly-1 O-5 S4

5 complex with a racemic Trp ([L-Trp]/[D-Trp] = 1/1 (mol/mol)). Further addition of a 3 μl of the L-Trp solution ([L-Trp]/[D-Trp] = /1 (mol/mol)) was done before the absorption and CD measurements (Figure 5A). The same helicity inversion experiments were also performed for poly-1 L-Trp in acidic water (Figure S1A) and poly- 1 (1R,S) and (1S,R)- in acidic and weak alkaline water (Figures 5 and S1). 4. Molecular Modeling and Calculations Molecular modeling and molecular mechanics calculations were conducted with the Dreiding force field (version.1) 3 as implemented in CERIUS software (version 3.8; Molecular Simulation Inc., urlington, MA, USA) running on an Indigo -Extreme graphics workstation (Silicon Graphics). The polymer model ( repeating units of monomer units) of poly-1 was constructed using a Polymer uilder in CERIUS. Achiral cyanine dye (O-5) was also constructed. Charges on atoms of poly-1 and O-5 were calculated using charge equilibration (QEq) in CERIUS ; total charges of the molecules were zero. The starting main chain conformation of a polymer model was defined as the double bond geometry (cis or trans) and a conformation of a rotational single bond. The double bond geometry was fixed to cis and the initial dihedral angle of a single bond from planarity was set to 15 (transoid) based on the calculated righthanded helical structure of poly((4-carboxyphenyl)acetylene). 4 The helix-sense of poly- 1 was tentatively assigned on the basis of the Cotton effect signs of the ICDs of analogous helical polyacetylene 5 and their AFM measurement results. 6 The constructed model ( mer) was optimized by the smart minimizer (SM) method. The energy minimization was continued until the root-mean-square (rms) value became less than.1 kcal mol -1 Å -1. The average dihedral angle of the double bonds from planarity was ± 3.7. The initial structure of O-5 was also energy-minimized by the SM method. The optimized five O-5 molecules were manually placed into the cavity of poly-1. The complex was further energy minimized by the SM method to relieve S5

6 unfavorable van der Waals contacts. The average dihedral angle of the double bonds from planarity for the optimized poly-1 complexed with O-5 was 163. ± 4.7. The obtained helically twisted O-5 aggregates aligned in the cavity of a helical poly-1 is shown in Figure References and Notes (1) Nonokawa, R.; Yashima, E.. Am. Chem. Soc. 3, 15, () Glasoe, P. K.; Long, F. A.. Phys. Chem. 196, 64, (3) (a) Mayo, S. L.; Olafson,. D.; Goddard III, W. A.. Phys. Chem. 199, 94, (b) Rappé, A. K.; Goddard III, W. A.. Phys. Chem. 1991, 95, (4) Yashima, E.; Matsushima, T.; Okamoto, Y.. Am. Chem. Soc. 1997, 119, (5) Maeda, K.; Morino, K.; Okamoto, Y.; Sato, T.; Yashima, E.. Am. Chem. Soc. 4, 16, (6) (a) Sakurai, S.-i.; Okoshi, K.; Kumaki,.; Yashima, E. Angew. Chem., Int. Ed. 6, 45, (b) Sakurai, S.-i.; Okoshi, K.; Kumaki,.; Yashima, E.. Am. Chem. Soc. 6, 18, S6

7 O O N I n O-3 (n=1) O-5 (n=) O-7 (n=3) N N I I-5 N N S I S-5 S N N I Q-5 N 1 1 A: O-3 : O-7 with poly-1 without poly-1 a: ph 7.1 b: ph.1 c: ph 7.1 d: ph with poly-1 a: ph 7.1 b: ph.1 without poly-1 c: ph 7.1 d: ph C: I-5 with poly-1 a: ph 7.1 b: ph.1 without poly-1 c: ph 7.1 d: ph D: S-5 E: Q-5 with poly-1 a: ph 7.1 b: ph.1 without poly-1 c: ph 7.1 d: ph with poly-1 without poly-1 d: ph.1 a: ph 7.1 b: ph.1 c: ph Figure S1. Absorption spectral changes of O-3 (A), O-7 (), I-5 (C), S-5 (D), and Q-5 (E) in the presence (a and b) and absence (c and d) of poly-1 in neutral (a and c, blue lines, ph 7.1) and acidic water (b and d, red lines, ph.1). O-3, O-7, I-5, S-5, and Q-5 immediately precipitated at ph.1 in the absence of poly-1, and the precipitates were removed by filtration before absorption measurements. All spectra were measured in a.5-mm quartz cell at room temperature (ca. 4 C). [poly-1] = 1. mg/ml (.6 mm monomer unit), [dye] =.6 mm, and [HClO 4 ] =. M (b and d). S7

8 pd a) O-5 in D O 8. b) O-5 in CD 3 OD c) poly-1 in D O 7.7 d) poly-1 with O-5 in D O HClO 4 aq. e) poly-1 with O-5 in HClO 4 -D O.4 + CD 3 OD f) poly-1 with O-5 in HClO 4 - D O/CD 3 OD (1/1, v/v) (ppm) Figure S. 1 H NMR spectra (5 MHz, 9 C) of O-5 in D O (a) and CD 3 OD (b), poly-1 in D O (c), and poly-1 with O-5 in D O (d), HClO 4 D O (e), and HClO 4 D O/CD 3 OD (1:1 = v/v) (f). [poly-1] = 1. (c, d, and e) and.5 mg/ml (f), [O-5] =.6 (a, b, d, and e) and.13 mm (f), [HClO 4 ] =.6 (e) and.13 M (f). S8

9 . A a: b: 6 min c:.5 h d: 1 h e: h f: 9 h at 669 nm C 3 sec3 min h 9 h 4 h g: 4 h Time (min) Figure S3. Absorption spectral changes (A), the plots of absorbance at 669 nm (), and visible difference (C) of O-5 in the presence of poly-1 in acidic water (ph.1) with time. All spectra were measured in a.5-mm quartz cell at room temperature (ca. 5 C). [poly-1] = 1. mg/ml (.6 mm monomer unit), [O-5]/[poly-1] =.1, and [HClO 4 ] =. M. S9

10 Effect of ph on helicity induction in poly-1 CD (mdeg) A: D-Trp ph a:.1 b: 3.7 c: 6.6 d: 1. e: ( ) f: ( ) g: ( ) h: ( ) CD (mdeg) : (1R,S)- ph a:.1 b: 3.7 c: 6.6 d: 1. e: ( ) f: ( ) g: ( ) h: ( ) Figure S4. CD (a d) and absorption spectral changes (e h) of poly-1 with D-Trp (A) and (1R,S)- () in the absence of O-5 in acidic water upon the addition of aqueous NaOH at room temperature (ca. 5 6 C). [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, [D-Trp]/[poly-1] = 1, and [HClO 4 ] =.36 (A) and. M (). S1

11 Effect of time on -aggregates formation of O-5 in the presence of poly-1 and L-Trp or (1R,S)-.5 at 669 nm sec 71 sec b: (1R,S)- a: L-Trp Time (min) Figure S5. Changes in the absorbance at 669 nm corresponding to the -aggregated O- 5 chromophore upon the addition of L-Trp (a, red line) and (1R,S)- (b, blue line) in the presence of poly-1 in acidic water (ph.1) at room temperature (ca. 5 C) before annealing. All spectra were measured in a.5-mm quartz cell. [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, [L-Trp]/[poly-1] = 1, [(1R,S)-]/[poly-1] = 5, [HClO 4 ] =.5 (a) and. M (b). S11

12 Effect of temperature on helical -aggregates formation of O-5 in the presence of helical poly-1 induced by L-Trp or (1R,S)- CD (mdeg) 4 A: L-Trp : (1R,S)- Heating time = 6 sec 5 Heating time = 6 sec CD at 669 nm (mdeg) Heating temp. ( C) Temp. ( C) CD (mdeg) CD at 669 nm (mdeg) Temp. ( C) Heating temp. ( C) Figure S6. CD and absorption spectral changes in chiral -aggregates of O-5 induced by the helical poly-1 assisted by L-Trp (A) and (1R,S)- () in acidic water after heating at various temperatures for 6 sec followed by cooling in an ice bath for 6 sec. Inset shows the plots of CD intensity of chiral -aggregates of O-5 at 669 nm verses the heating temperature. All spectra were measured in a.5-mm quartz cell at room temperature (ca. 4 6 C). [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, [L-Trp]/[poly- 1] = 1, [(1R,S)-]/[poly-1] = 5, and [HClO 4 ] =.5 (A) and. M (). S1

13 Effect of heating time on helical -aggregates formation of O-5 in the presence of helical poly-1 induced by L-Trp or (1R,S)- CD (mdeg) A: L-Trp CD at 669 nm (mdeg) Heating temp. = 55 C Time (min) Heating time (sec) CD (mdeg) 1 1 : (1R,S)- Heating temp. = 55 C CD at 669 nm (mdeg) Time (min) Heating time (sec) Figure S7. CD and absorption spectral changes in chiral -aggregates of O-5 induced by the helical poly-1 assisted by L-Trp (A) and (1R,S)- () in acidic water after heating at 55 C for appropriate time followed by cooling in an ice bath for 6 sec. Inset shows the plots of CD intensity of chiral -aggregates of O-5 at 669 nm verses the heating time. All spectra were measured in a.5-mm quartz cell at room temperature (ca. 4 5 C). [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, [L-Trp]/[poly-1] = 1, [(1R,S)- ]/[poly-1] = 5, and [HClO 4 ] =.5 (A) and. M (). S13

14 Effect of HClO 4 concentration on helical -aggregates formation of O-5 in the presence of helical poly-1 induced by L-Trp or (1R,S)- CD (mdeg) A: L-Trp : (1R,S)- Heating temperature = 5 C Heating temperature = 5 C Heating time = 6 sec Heating time = 6 sec [HClO 4 ] =.5 M.36 M CD (mdeg) 1 1 [HClO 4 ] =. M.35 M Figure S8. CD and absorption spectral changes in chiral -aggregates of O-5 induced by the helical poly-1 assisted by L-Trp (A) and (1R,S)- () in acidic water ([HClO 4 ] =.5 or. (blue lines) and.36 or.35 M (red lines)) after heating at 5 C for 6 sec followed by cooling in an ice bath for 6 sec. All spectra were measured in a.5- mm quartz cell at room temperature (ca. 6 C). [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, [L-Trp]/[poly-1] = 1, [(1R,S)-Trp]/[poly-1] = 5. S14

15 CD ca. 67 (mdeg) Abs. ca ph 8.9 () ph 11.8 () ph 1.4 () ph 8.9 (E) ph 11.8 (E) ph 1.4 (E) Time (h) Figure S9. Time-dependent CD and absorbance intensity changes in chiral - aggregates of O-5 induced by the helical poly-1 assisted by (1R,S)- ([(1R,S)- ]/[poly-1]=5) at different ph. ph was adjusted by adding NaOH aq. to the original acidic polymer solution at ph 1.4. Changes in the CD intensity (top) and absorbance (bottom) at ca. 67 nm were followed in a.5-mm cell at 5 C. [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1. S15

16 CD (mdeg) [L-Trp]/[D-Trp] = c: 5:1 ( ) b: 5: 5 ( ) a: 5: ( ) d: ( ) e: ( ) f: ( ) A CD (mdeg) 1 1 [(1S,R)-]/[(1R,S)-] = c: 5:1 ( ) b: 5: 5 ( ) a: 5: ( ) d: ( ) e: ( ) f: ( ) Figure S1. CD (a c) and absorption spectral changes (d f) in chiral -aggregates of O-5 induced by the helical poly-1 assisted by L-Trp ([L-Trp]/[poly-1] = 1) (A) and (1S,R)- ([(1S,R)-]/[poly-1]=5) in acidic water (ph.1 (A) and 1.4 ()) upon the addition of D-Trp ([D-Trp]/[L-Trp] = (a and d, red lines), 1/1 (b and e, green lines), and /1 (c and f, blue lines)) (A) and (1R,S)- ([(1R,S)-]/[(1S,R)-]) = (a and d, red lines), 1/1 (b and e, green lines), and /1 (c and f, blue lines)) (), respectively, at room temperature (ca. 4 5 C). All spectra were measured in a.5-mm quartz cell. [poly-1] = 1. mg/ml, [O-5]/[poly-1] =.1, and [HClO 4 ] =.36 (A) and. M (). S16

17 CD ca. 67 (mdeg) ln (CD/CD t= ) 3 A 5 H H H C HH 15 HH H HHHHH 5 C 1 H HH H H H 5 H 3 C CD ca. 67 (mdeg) Time (h) Time (min) C 4 C 45 C H.5 C D -. H C HH -.4 HH C -.6 H H H HH H HH 5 C C -.5 H -1. HH H H 3 C C Time (h) ln (CD/CD t= ) Time (min) lnk /T x1 3 (K -1 ) E Figure S11. Racemization kinetics of chiral -aggregates of O-5 in water at ph 8.9. Changes in CD intensity at ca. 67 nm were followed in a 1.-mm cell at, 5, 3 (A), 35, 4, and 45 C (). [poly-1] =.6 mg/ml, [O-5]/[poly-1] =.1, [(1R,S)-]/[poly-1] = 5, [(1R,S)-]/[(1S,R)-]=1/1. First-order plots of ln (CD/CD t= ) versus time at, 5, 3 (C), 35, 4, and 45 C (D) and Arrhenius plot for k (E). CD spectral changes were measured at appropriate time intervals at, 5, and 3 C in (A) and the CD intensity changes at ca. 67 nm were then plotted against time, while the CD intensity changes at ca. 67 nm were directly followed at 35, 4, and 45 C in (). S17

18 Table S1. Racemization Kinetics Data for Chiral -Aggregates of O-5 in Water at ph 8.9. temperature ( C) k x1 5 (sec -1 ) correlation function lnk t 1/ (min) S18