Dissipative Assembly of Aqueous Carboxylic Acid

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Dissipative Assembly of Aqueous Carboxylic Acid Anhydrides Fueled by Carbodiimides Supporting Information Lasith S. Kariyawasam and C. Scott Hartley* Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA Table of Contents Experimental . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . Starting materials . . . . . . . . . . . . . . . . . . Independent synthesis of MEA-An . . . . . . . . Independent synthesis of TEG-Cy . . . . . . . . TEG-Cy alone . . . . . . . . . . . . . . . . . Mixture of TEG-Cy and linear anhydrides

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S3 S3 S3 S5 S7 S7 S8

Monitoring of assembly by IR spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S9 KSB-An IR spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S9 MEA-An IR spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S9 Monitoring of pH changes during assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S10 KSB-Ac pH changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S10 MEA-Ac pH changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S11 DFT chemical shift predictions for cyclic anhydrides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S11 Reaction monitoring by 1H NMR spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S12 TEG-Cy and PEG-Cy without added salts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S13 Multiple injections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S13 DFT geometry predictions of the K+ complexes of 18-crown-6 and TEG-Cy . . . . . . . . . . . . . . . . . . S15 Kinetic models . . . . . . . . . . . . Monoacid systems . . . . . . . . . Diacid systems . . . . . . . . . . . Data analysis in Python . . . . . .

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S15 S15 S16 S17

Kinetic data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S18 Fit parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S18 Python script for kinetic fits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S19 Raw kinetic data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S27 Calculated geometries . . . . . . . . . . . . TEG-Cy (B3LYP/6-31G(d)) . . . . . . . . S2 (B3LYP/6-31G(d)) . . . . . . . . . . . . K+ ⊂ 18-Crown-6 (B3LYP/6-31+G(d,p)) K+ ⊂ TEG-Cy (B3LYP/6-31+G(d,p)) . . .

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S34 S34 S35 S37 S38

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S39

List of Figures S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 S17 S18 S19 S20 S21 S22 S23 S24 S25 S26 S27 S28 S29 S30 S31 S32 S33 S34 S35 S36 S37 S38 S39

1H

NMR spectrum (500 MHz, CDCl3 ) of TEG-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . . NMR spectrum (126 MHz, CDCl3 ) of TEG-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1H NMR spectrum (500 MHz, CDCl ) of PEG-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 13C NMR spectrum (126 MHz, CDCl ) of PEG-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1H NMR spectrum (500 MHz, CDCl ) of MEA-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 13C NMR spectrum (126 MHz, CDCl ) of MEA-Ac. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1H NMR spectrum (500 MHz, CDCl ) of MEA-An. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 13C NMR spectrum (126 MHz, CDCl ) of MEA-An. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1H NMR spectrum (500 MHz, CDCl ) of TEG-Cy. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 13C NMR (126 MHz, CDCl ) spectrum of TEG-Cy. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1H NMR spectrum (500 MHz, CDCl ) of a mixture of TEG-Cy and linear anhydrides. . . . . . . 3 IR spectroscopy monitoring of KSB-An (0.5 eq EDC). . . . . . . . . . . . . . . . . . . . . . . . . . IR spectroscopy monitoring of MEA-An (4 eq EDC). . . . . . . . . . . . . . . . . . . . . . . . . . . IR spectroscopy monitoring of MEA-An (2 eq EDC). . . . . . . . . . . . . . . . . . . . . . . . . . . pH vs time for KSB-An system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pH vs time for MEA-An system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculated energies and relative chemical shifts for model compound S1. . . . . . . . . . . . . . Optimized geometries of TEG-Cy and S2, with calculated isotropic shieldings PCM indicated. Monitoring of assembly of TEG-Cy and PEG-Cy without added salts. . . . . . . . . . . . . . . . 1H NMR monitoring of the MEA-An system with multiple injections. . . . . . . . . . . . . . . . 1H NMR monitoring of the TEG-Cy system with multiple injections. . . . . . . . . . . . . . . . . Optimized geometries of the potassium ion complexes of 18-crown-6 and TEG-Cy. . . . . . . . Kinetic parameters for the MEA-An system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kinetic parameters for the TEG-Cy system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kinetic parameters for the PEG-Cy system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of KSB-An. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of MEA-An, without added salt. . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of MEA-An, with 1 M LiCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of MEA-An, with 1 M NaCl. . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of MEA-An, with 1 M KCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of MEA-An, with 1 M CsCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of TEG-Cy, with 1 M LiCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of TEG-Cy, with 1 M NaCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of TEG-Cy, with 1 M KCl. . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of TEG-Cy, with 1 M CsCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of PEG-Cy, with 1 M LiCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of PEG-Cy, with 1 M NaCl. . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of PEG-Cy, with 1 M KCl. . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of assembly of PEG-Cy, with 1 M CsCl. . . . . . . . . . . . . . . . . . . . . . . . . . . 13C

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S3 S4 S4 S5 S5 S6 S6 S7 S8 S8 S9 S9 S10 S10 S11 S11 S12 S12 S13 S14 S14 S15 S18 S19 S19 S28 S28 S29 S29 S30 S30 S31 S31 S32 S32 S33 S33 S34 S34

List of Schemes S1

General structure of linear anhydride diacids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S16

List of Tables S1 S2 S3

Computational data for TEG-Cy and linear dimer S2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . S12 Computational data for potassium ion complexes of TEG-Cy and 18-crown-6. . . . . . . . . . . . . . S15 Fit parameters for the KSB-An system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S18 S2

Experimental General Unless otherwise noted, all starting materials, reagents, and solvents were purchased from commercial sources and used without further purification. NMR spectra were measured for CDCl3 or D2 O solutions using a Bruker Avance 500 MHz NMR spectrometer. DFT calculations were performed using Gaussian 09, rev. B.01.1 All energy minima were verified to have 0 imaginary frequencies by vibrational frequency analysis.

4.5

ppm

3.75 3.74 3.74 3.74 3.69 3.68 3.68 3.67 3.66 3.66 3.65 3.65 3.64

4.16

Starting materials The monoacids KSB-Ac and MEA-Ac are commercially available and were used without further purification. The diacids TEG-Ac and PEG-Ac are known compounds synthesized according to literature procedures.2 NMR spectra of as-synthesized TEG-Ac and PEG-Ac are shown in Figures S1–S4. They were also characterized by highresolution mass spectrometry, giving m/z = 311.13346 for TEG-Ac (calcd 311.13421 for [TEG-Ac+H+ ]) and m/z = 355.15981 (calcd 355.15987 for [PEG-Ac+H+ ]).

4.0

3.5

10

5

Figure S1. 1H NMR spectrum (500 MHz, CDCl3 ) of TEG-Ac.

S3

0

68.15

70.24 70.17 70.09

70.75

70.75 70.24 70.17 70.09 68.15

173.72

70

ppm

200

68

150

100

50

0

3.58 3.57 3.52 3.50

4.01

Figure S2. 13C NMR spectrum (126 MHz, CDCl3 ) of TEG-Ac.

4.0

ppm

3.5

10

5

Figure S3. 1H NMR spectrum (500 MHz, CDCl3 ) of PEG-Ac.

S4

0

ppm

200

70.72 70.24 70.21 70.13 68.11

68.11

70.24 70.21 70.13

70.72

173.72

70

68

150

100

50

0

Figure S4. 13C NMR spectrum (126 MHz, CDCl3 ) of PEG-Ac.

3.267

3.485 3.480 3.476 3.473 3.467

3.615 3.609 3.606 3.602 3.597

4.039

Independent synthesis of MEA-An MEA-Ac (115 µL, 1.0 mmol), N,N′-dicyclohexylcarbodiimide (DCC) (106 mg, 0.5 mmol, 0.5 eq) and CCl4 (5 mL) were added to a scintillation vial and stirred at r.t. for 1 h. The mixture was then filtered through a cotton plug and the filtrate cooled at −4 ℃ in the freezer. The mixture was then filtered again through a cotton plug and concentrated, giving a mixture of MEA-An and MEA-Ac (2.8:1). NMR spectroscopy (see below) supports the assignments made for the kinetic runs in D2 O (i.e., that the key anhydride methylene signal is deshielded by 0.2–0.3 ppm relative to the acid).

3 2 2 ppm3.2

4.2-15.011

4.04.2

2.02 2.02 3.84.0

Figure S5. 1H NMR spectrum (500 MHz, CDCl3 ) of MEA-Ac.

S5

3.63.8

2.03 2.03

3 3.43.6

3.23.4

150

58.564

71.422 70.426 67.958

173.661 ppm

100

50

ppm

0.704 4.2

3.351

*

*

2

3.389

3.576 3.567 3.562 3.558 3.555 3.549

3.728 3.723 3.719 3.716 3.710 3.707

4.133

4.275

Figure S6. 13C NMR spectrum (126 MHz, CDCl3 ) of MEA-Ac.

2.73 4.0

3.8

2.78 3.6

0.98 3.1 3.4

3.2

Figure S7. 1H NMR spectrum (500 MHz, CDCl3 ) of MEA-An, obtained as a mixture with MEA-Ac (signals labeled *).

S6

59.049

71.979 71.660 71.101 68.938 68.642

166.241

172.880

*

ppm

150

100

50

Figure S8. 13C NMR spectrum (126 MHz, CDCl3 ) of MEA-An, obtained as a mixture with MEA-Ac (signal labeled *).

Independent synthesis of TEG-Cy When anhydride formation is carried out with DCC in CCl4 , we obtain the cyclic anhydride TEG-Cy as the major product (as determined by NMR spectroscopy and mass spectrometry), whereas in CH2 Cl2 we obtain a mixture of cyclic and linear anhydrides.

TEG-Cy alone TEG-Ac (0.3408 g, 1.098 mmol), DCC (0.2290 g, 1.110 mmol, 1.011 equiv) and CCl4 (4 mL) were added into a vial and the reaction mixture was stirred at r.t. for 1 h. It was then filtered through cotton, and the colorless filtrate was let stand in the freezer. No additional precipitate was observed. The solution was concentrated to a yellowish liquid containing a small amount of white solid. It was resuspended in CCl4 , filtered through a cotton plug, and concentrated again to give a mixture of predominantly TEG-Cy: 1H NMR (500 MHz, CDCl3 ) δ 4.41 (s, 4H), 3.74 (m, 4H), 3.67 (m, 4H), 3.65–3.60 (m, 8H); 13C NMR (126 MHz, CDCl3 ) δ 166.7, 71.6, 71.0, 70.72, 70.69, 69.3; MS (ESI) calcd for C12 H21 O8 (M+H+ ) 293.12, found 293.24.

S7

3.75 3.75 3.74 3.74 3.68 3.67 3.66 3.62

4.41 ppm1

4-15.01

34

23

12

72

ppm

150

69.27

71.03 70.72 70.69

71.57

71.57 71.03 70.72 70.69 69.27

166.72

Figure S9. 1H NMR spectrum (500 MHz, CDCl3 ) of TEG-Cy. The impurities correspond to linear anhydrides/acids and DCC/urea.

70

100

50

Figure S10. 13C NMR (126 MHz, CDCl3 ) spectrum of TEG-Cy. Note that there are no signals corresponding to the carboxylic acid functional group, and that the number of signals (6) is consistent with the symmetry of TEG-Cy.

Mixture of TEG-Cy and linear anhydrides TEG-Ac (0.3464 g, 1.11 mmol) and DCC (0.2360 mg, 1.11 mmol, 1.0 eq) were added to a vial, followed by CH2 Cl2 (4 mL). The reaction mixture was stirred overnight at rt, then filtered through cotton and concentrated to give a mixture of TEG-Cy and linear anhydrides and acids.

S8

4.39 4.27 4.27 4.26 4.12 4.11 3.71 3.70 3.70 3.69 3.66 3.65 3.65 3.64 3.64 3.62 3.61 3.60 CH2CO2H –CH2CO2CO– TEG-Cy

ppm

4

3

2

1

Figure S11. 1H NMR spectrum (500 MHz, CDCl3 ) of a mixture of TEG-Cy and linear anhydrides.

Monitoring of assembly by IR spectroscopy

Transmission

KSB-An IR spectroscopy KSB-Ac (24 mg, 0.10 mmol, 1.0 eq) was dissolved in distilled water (0.5 mL). EDC (10 mg, 0.05 mmol, 0.5 eq) was dissolved separately in distilled water (0.5 mL). The two solutions were mixed (time = 0), and immediately monitored as a droplet on the surface of the ATR cell of an IR spectrometer. The background spectrum of distilled water was subtracted from each spectrum. The peak at ~1800 cm−1 is assigned to the symmetric stretch of the anhydride (the asymmetric stretch is typically weaker and should overlap with the carboxylic acid carbonyl stretching mode). The peak(s) at ~1700 cm−1 correspond(s) to both the acid and the EDC; after an initial decrease, this peak grows back in. The peaks at ~1570 and ~1630 cm−1 correspond to the urea.

0.78 3.73 6.77 9.20 11.58 13.95

↑ ↑↓ ↓ ↓

1900

1800

1700 −1 ν (cm )

1600

1500

Figure S12. IR spectroscopy monitoring of KSB-An (0.5 eq EDC). Times are in minutes.

MEA-An IR spectroscopy MEAA (46 µL, 0.40 mmol, 1.0 eq) was initially dissolved in 1.00 mL of distilled water. EDC (155 mg, 2.0 eq; or 310 mg, 4.0 equiv) was also dissolved in 1.00 mL of distilled water in a separate vial. Both the vials were cooled in salt-ice baths. The reactants were mixed (time = 0) and immediately monitored as a droplet on the surface of the ATR cell of an IR spectrometer. The background spectrum of distilled water was subtracted from each spectrum. The assignments parallel those for KSB-An, but note that the relative concentration of anhydride/acid is much lower.

S9

1805

1865

Transmission 1900

0.27 0.55 0.83 1.12 1.38 1.67

1800

1700 −1 ν (cm )

1600

1500

Transmission

Figure S13. IR spectroscopy monitoring of MEA-An (4 eq EDC). The inset shows the evolution of the peak corresponding to the anhydride. Times are in minutes.

0.33 0.68 0.97 1.23 1.52

1800

1805

1865

1900

1700 −1 ν (cm )

1600

1500

Figure S14. IR spectroscopy monitoring of MEA-An (2 eq EDC). The inset shows the evolution of the peak corresponding to the anhydride. Times are in minutes.

Monitoring of pH changes during assembly KSB-Ac pH changes KSB-Ac (362 mg, 101 mM) and pyridine (2.4 µL, 2.0 mM) were added to a volumetric flask and diluted to 10.00 mL with distilled water to prepare a stock solution. A solution of EDC in water (4.0 mL, 0.3 eq) was added to the stock solution (8.0 mL). The pH of the reaction mixture was monitored over time at room temperature using a standard pH meter. The EDC solution (4 mL) was added two more times into the reaction mixture. For the control experiment, pyridine (2.4 µL, 2.0 mM) was diluted to 10.00 mL with distilled water in a volumetric flask to prepare a stock solution. A solution of EDC in water (4.0 mL, same as in KSB-Ac experiment) was added to the stock solution (8.0 mL). The pH of the reaction mixture was monitored over time at room temperature using a standard pH meter.

S10

Injection 1

Injection 2

Injection 3

pH

pH

Control

8.0

3.5

3.0

7.5

7.0 2.5 0

5

10

0

5 10 Time (min)

0

5

10

0

2

4

6 8 Time (min)

10

12

Figure S15. pH vs time for KSB-An system. The control experiment is identical but with no KSB-Ac.

MEA-Ac pH changes MEA-Ac (170 µL, 100 mM) and pyridine (2.4 µL, 2.0 mM) were added to a volumetric flask and diluted to 10.00 mL with distilled water to prepare a stock solution. An ice-cold solution of EDC in water (4 mL, 4 eq) was added to the ice-cold stock solution (8 mL). The pH of the reaction mixture was monitored over time with the reaction mixture kept in an ice-salt bath. For the control experiment, pyridine (2.4 µL, 2.0 mM) was diluted to 10.00 mL with distilled water in a volumetric flask to prepare a stock solution. An ice-cold solution of EDC in water (4 mL, same as in MEA-Ac experiment) was added to the ice-cold stock solution (8 mL). The pH of the reaction mixture was monitored over time with the reaction mixture kept in an ice-salt bath. 9.0

Control

3.5

pH

pH

8.5 3.0

8.0 2.5 7.5 0

1

2

3 4 Time (min)

5

6

7

0

1

2

3 4 Time (min)

5

6

7

Figure S16. pH vs time for MEA-An system. The control experiment is identical but with no MEA-Ac.

DFT chemical shift predictions for cyclic anhydrides The general effect of conformation on chemical shifts in the MEA-An, TEG-Cy, and PEG-Cy systems was first probed using model compound S1. A conformational energy surface for rotation about the O1 –C2 –C3 –O4 bond was generated at the PCM(water)/B3LYP/6-31G(d) level. Two conformers, one with O1 and O4 syn-periplanar (φ ≈ 0◦ ) and one with them anti-periplanar (φ ≈ 180◦ ) were identified. The anti-periplanar conformer is predicted to be roughly 1.3 kcal/mol more stable at this level of theory, and thus presumably favored in the acyclic anhydrides (whereas the cyclic anhydrides would be forced into the syn-periplanar conformation). NMR isotropic shieldings were calculated for each geometry at the PCM(water)/WP04/6-31G(d) level.3,4 The chemical shifts for the methylene protons α to the carbonyl group (on C2 ) were found to be deshielded by 0.07 ppm in the (less favorable) synperiplanar conformer.

S11

H

0

2

0.05

(ppm)

3 O O 2 4 1 O O S1

0.05

0.07 ppm

Rel.

H

Rel. E (kcal/mol)

3

0.10

1

0.15 0

180

120 60 0 60 120 Dihedral O1–C2–C3–O4 (°)

Figure S17. Calculated energies (PCM(water)/B3LYP/6-31G(d)) (PCM(water)/WP04/6-31G(d)) for model compound S1.

and

180

relative

chemical

shifts

These results were then extended to explicit models of TEG-Cy and linear dimer S2. Their geometries were optimized at the B3LYP/6-31G(d) level with NMR isotropic shieldings calculated at the PCM(water)/WP04/6-31G(d) level. The results are in line with those for S1: a chemical shift difference of 0.10 ppm, with the cyclic anhydride predicted to be deshielded relative to the (all anti) linear anhydride. This is consistent with the assignments made in the experimental spectra. Cartesian coordinates for the optimized geometries are provided below (pp S34, S35). IS = 28.26 ppm

IS = 28.36 ppm TEG-Cy

S2

Figure S18. Optimized geometries of TEG-Cy and S2 (B3LYP/6-31G(d)), with calculated isotropic shieldings (IS) (PCM(water)/WP04/6-31G(d)) indicated.

Structure TEG-Cy (C 2 ) S2

Energy (Eh ) −1071.029995 −2218.551138

ZPC (Eh ) 0.331503 0.688198

Total Energy (Eh ) −1070.698492 −2217.862940

IF 0 0

Table S1. Computational data (B3LYP/6-31G(d)) for TEG-Cy and linear dimer S2. ZPC = zero-point correction, IF = number of imaginary frequencies.

Reaction monitoring by 1H NMR spectroscopy The reactions were monitored by 1H NMR spectroscopy (500 MHz). All concentrations were referenced to the methyl peak of the acetyl group of N,N -dimethylacetamide (DMA), included as an internal standard (this peak was also used to calibrate the chemical shift scale). Stock solutions (10.00 mL) were prepared of the appropriate carboxylic acid (150 mM for monoacids, 75 mM for diacids), DMA (100 mM), and pyridine-d 5 (3.0 mM). The appropriate salts (LiCl, NaCl, KCl, or CsCl) were added to portions of this stock solution depending on the specific experiment being run (such that the final concentration of salt would be 1.0 M). A separate solution of EDC in D2 O was also prepared at such a concentration that 200 μL would deliver the target stoichiometry. For the lowtemperature experiments at 276 K (MEA-An, TEG-Cy, PEG-Cy), all of the solutions were cooled in an ice bath until immediately before beginning a run. The NMR spectrometer was locked and shimmed on a 600 μL aliquot of the stock solution (after being equilibrated at the appropriate temperature). For each run, a standard NMR tube was charged with 400 μL of the acid-containing S12

solution, then treated with 200 μL of the EDC solution. The reaction mixture was quickly mixed, inserted into the spectrometer, and acquisition started. The time of first mixing was taken as t = 0. Each time point constitutes a single scan, with the time taken as the midpoint of acquisition. All experiments were done in triplicate. The raw data is given in Figures S27–S39. TEG-Cy and PEG-Cy without added salts As mentioned in the text, assembly of TEG-Cy and PEG-Cy was also attempted in the absence of added salts. As shown in Figure S19, the reaction works as expected, but is inconveniently faster than in the presence of any of the salts. TEG-Cy

PEG-Cy

Figure S19. Monitoring of assembly of TEG-Cy (left) and PEG-Cy (right) without added salts (276 K). 2 eq of EDC (per acid group) were used (to achieve roughly 50% conversion).

Multiple injections The response to multiple injections was tested for the MEA-An and TEG-Cy systems (with 1 M KCl). Briefly, initial experiments were carried out as for the single-injection runs. The samples were then removed from the spectrometer, treated with another dose of the EDC, and then monitored again (hence the dilution with each injection). Three total injections were attempted in both cases; however, for the MEA-An system, the buildup of byproducts gave complex behavior after the third injection that could not be satisfactorily analyzed.

S13

800

Conc (mM)

600

400

200

0

Conc (mM)

80 60 40 20 0

0

5 10 Time (min) (1st inj.)

0

5 10 Time (min) (2nd inj.)

Figure S20. 1H NMR monitoring of the MEA-An system with multiple injections (276 K, D2 O, 2 mM pyridine-d 5 ).

Conc (mM)

800 600 400 200 0 50

Conc (mM)

40 30 20 10 0

0

5 10 0 5 10 Time (min) (1st inj.) Time (min) (2nd inj.)

0

5 10 Time (min) (3rd inj.)

Figure S21. 1H NMR monitoring of the TEG-Cy system with multiple injections (276 K, D2 O, 2 mM pyridine-d 5 , 1 M KCl).

S14

DFT geometry predictions of the K+ complexes of 18-crown-6 and TEG-Cy To compare the (possible) binding of K+ by TEG-Cy to that of 18-crown-6, the (gas phase) geometries of the complexes were optimized at the B3LYP/6-31+G(d,p) level, which has been previously used to study (hydrated) 18-crown-6 complexes.5 The results show that while the anhydride oxygen atom in TEG-Cy is more weakly coordinated than the others, its bond length to K is predicted to be actually very similar to those in 18-crown-6.

2.82

2.83

2.74

2.79

2.67

Figure S22. Optimized geometries (B3LYP/6-31+G(d,p)) of the potassium ion complexes of 18-crown-6 (left) and TEG-Cy (right). Predicted O−K bond lengths are given in Å.

Structure 18-Crown-6–K+ (Ci ) TEG-Cy–K+ (C 1 )

Energy (Eh ) −1522.883502 −1670.916013

ZPC (Eh ) 0.370689 0.331585

Total Energy (Eh ) −1522.512813 −1670.584428

IF 0 0

Table S2. Computational data for potassium ion complexes of TEG-Cy and 18-crown-6 (B3LYP/631+G(d,p)). ZPC = zero-point correction, IF = number of imaginary frequencies.

Kinetic models Monoacid systems The monoacid systems were analyzed using the following model: k

1 → I Ac + E −

kAn

i I + Ac −− → An + U

kAc

i I −−→ Ac + U

k

2 An − → 2Ac

where Ac is the monoacid, E is the EDC, I is an activated carboxylic acid intermediate (e.g., O-acylurea, acyl pyridinium ion, or equivalent), An is the anhydride, and U is the urea. This system yields the following system of differential equations: d[Ac] dt d[An] dt d[I] dt d[E] dt d[U] dt

Ac = −k1 [Ac][E] − kAn i [I][Ac] + ki [I] + 2k2 [An]

(1)

= +kAn i [I][Ac] − k2 [An]

(2)

Ac = +k1 [Ac][E] − kAn i [I][Ac] − ki [I]

(3)

= −k1 [Ac][E]

(4)

An = +kAc i [I] + ki [I][Ac]

(5)

S15

If we assume a steady-state in [I], we obtain instead: d[Ac] dt d[An] dt d[E] dt d[U] dt

= −k1 [E][Ac] + 2k2 [An] + =+

k1 K[Ac][E] k1 [E][Ac]2 − K + [Ac] K + [Ac]

k1 [E][Ac]2 − k2 [An] K + [Ac]

(6) (7)

= −k1 [E][Ac]

(8)

= +k1 [E][Ac]

(9)

An where K = kAc i /ki (i.e., direct hydrolysis of the intermediate vs anhydride formation). As discussed in the text, a steady-state was assumed for the MEA-An assembly. However, for the KSB-An system, a species believed to be an intermediate was detected at short reaction times, so [I] was explicitly included in the analysis. The k’s and K are explicitly fit as parameters, as are the initial concentrations of EDC ([E]0 ) and acid ([Ac]0 ). The other starting concentrations ([An]0 , [I]0 , [U]0 ) are assumed to be 0. Anhydride “yields” can be calculated from fits of these models. Equation (7) can be dived into two terms: anhydride formation and anhydride destruction (an identical argument can be made for equation (2)). Under the conditions of the experiments, we begin and end with no anhydride; that is, the total amount formed is the amount hydrolyzed:





0

∫ d[An] = +k1

0



[E][Ac]2 dt − k2 K + [Ac]





[An]dt = 0

(10)

0

The total amount of anhydride formed can be determined from either term but, in practice, it is more straightforward to do it from the destruction term. Thus, the yield is given by:

Yield =

k2

∫∞

[An]dt [E]0

0

(11)

where the initial concentration of EDC ([E]0 ) is obtained from the kinetic fits. Diacid systems The principal challenge in the diacid systems is that we can determine the total concentrations of linear anhydride and diacid functionality by NMR, but not the concentrations of specific species. We need to be able to establish the concentration of the starting diacids at any given moment since (to a first approximation) only they can cyclize to the macrocycles. We define a general diacid structure in the system as DAn (Scheme S1). That is, the starting materials TEG-Ac or PEG-Ac would be DA0 (x = 4 or 5, respectively), and linear anhydride oligomers would be all DAn with n > 0. O HO

O O x

O

O O

O O

O x

OH

n

DAn

Scheme S1. General structure of linear anhydride diacids.

By analogy with the monoacid system, we describe the diacid systems as follows:

S16

k

1 DAn + E − → In

kAc

i In −−→ DAn + U

kL

i DAn+m + U In + DAm −→

kC

i I0 −→ Cy + U

kL

2 DAn>0 −→ DAn + DAm

kC

2 Cy −→ DA0

where E and U are defined as above, DAn represents the total diacid species (Scheme S1), In represents all possible intermediate species (with n defined as for DAn ), and Cy is the cyclic anhydride. L L To analyze this system we assume that the rate constants k1 , kAc i , ki , and k2 are independent of n, and that the concentration of the starting diacids DA0 can be estimated from the total diacid concentration using a conversion factor ρ. We define ρ by analogy with a simple condensation polymerization: [DA0 ] = ρ[DAn ]

(12)

[Ac]0 = [Ac] + [L] + [Cy] [Ac] [Ac] ρ= = [Ac]0 − [Cy] [Ac] + [L]

(13) (14)

where [Ac] is the measured diacid concentration, [Ac]0 is the initial (total) diacid concentration, and [L] is the measured linear anhydride concentration. This estimate of ρ is clearly an approximation, but it behaves correctly at the limits of high/low conversion and should suffice given the other approximations inherent to this model. Framing this in terms of the measurable concentrations [Ac] (diacid), [L] (linear anhydride), [Cy], [E], and [U], and assuming a steady state in the intermediate, gives the following system of differential equations: d[Ac] dt d[L] dt d[Cy] dt d[E] dt d[U] dt

1 1 k1 K[Ac][E] 1 k1 [E][Ac]2 1 k1 ρKEM [Ac][E] = − k1 [Ac][E] + kL2 [L] + kC2 [C] + − − 2 2 K + [Ac] + ρKEM 2 K + [Ac] + ρKEM 2 K + [Ac] + ρKEM 2 k1 [E][Ac] =+ − kL2 [L] K + [Ac] + ρKEM k1 ρKEM [Ac][E] =+ − kC2 [Cy] K + [Ac] + ρKEM

(15) (16) (17)

= −k1 [Ac][E]

(18)

= +k1 [Ac][E]

(19)

L C L where K = kAc i /ki (as for the monoacid) and KEM = ki /ki (i.e., the effective molarity). As before, we fit the k’s, K’s, [Ac]0 , and [E]0 as parameters, and set the other starting concentrations to 0 ([L]0 , [Cy]0 , [U]0 ).

Data analysis in Python The models described above (equations (1)–(5), (6)–(9), and (15)–(19)) were fit to the experimental data using a script written in Python 3.5.2 with NumPy 1.12.0 and SciPy 0.18.1. The full script is given below on p S19. Briefly, the script solves the systems of differential equations numerically using SciPy’s odeint function, optimizing the fit by least squares. Because the concentrations are derived from NMR integration (which is expected to yield relative errors of roughly 10%), the errors for the minimization were weighted by a factor 1/(0.1 × conc), subject to a

S17

maximum to avoid overemphasizing low concentrations (≤5 mM). The script reads csv files with columns listing concentrations in the following order: time, anhydrides (linear then cyclic for diacids), acid, EDC, and urea. The script takes two arguments. The first specifies the model to use: 1 for monoacid, 1SS for monoacid with steady-state approximation, 2SS for diacid with steady-state approximation. The second is the filename of the csv file. The script automatically outputs the parameters, the best-fit curves from the kinetic model, and the plots of the data (shown in Figures S27–S39).

Kinetic data Fit parameters Parameters extracted from the fits to the kinetic models are summarized in Table S3 and Figures S23–S25. The plots themselves, including the raw parameters for each run, are given in Figures S27–S39.

k1 kAn i kAc i k2

0.034 ± 0.002 mM−1 min−1 0.0205 ± 0.0006 mM−1 min−1 0.286 ± 0.005 min−1 0.0494 ± 0.0005 min−1

Table S3. Fit parameters for the KSB-An system. The parameters are the means of three replicates, with error bars corresponding to the standard errors.

−1

k2 (min )

0.8 0.6 0.4 0.2 0

K (mM)

200

100

0.010

−1

−1

k1 (mM min )

0

0.005

0

No Salt

LiCl

NaCl

KCl

CsCl

Figure S23. Kinetic parameters for the MEA-An system. The parameters are the means of three replicates, with error bars corresponding to the standard errors.

S18

K (mM)

300 200 100 0 1.5

10

1

20

1.0

C

k2 (min )

EM (mM)

30

0.5 0 1.0

1

k2 (min )

1

0.010 0.005 0

0.5

L

k1 (mM min )

0.015

1

0

LiCl

NaCl

KCl

0

CsCl

LiCl

NaCl

KCl

CsCl

Figure S24. Kinetic parameters for the TEG-Cy system. The parameters are the means of three replicates, with error bars corresponding to the standard errors.

K (mM)

200 150 100 50

1.5

20

1

10

1.0

C

k2 (min )

EM (mM)

0

0.5 0 0.8

L

1

k2 (min )

1

0.010

k1 (mM min )

0.015

1

0

0.005 0

LiCl

NaCl

KCl

0.6 0.4 0.2 0

CsCl

LiCl

NaCl

KCl

CsCl

Figure S25. Kinetic parameters for the PEG-Cy system. The parameters are the means of three replicates, with error bars corresponding to the standard errors.

Python script for kinetic fits Note: This script is also provided as a .py (ASCII) file to facilitate use/adaptation. import numpy, scipy, sys, itertools, platform

S19

from matplotlib import pyplot as plt, rcParams from scipy.optimize import least_squares # Set name of data file as second argument. raw_data_file = sys.argv[2] # First argument specifies kinetic model. if sys.argv[1] == ”1SS”: def solved_kin_sys(starting_concs, ks, times): ”””Defines the kinetic model for the monoacid: (1) Ac + E -> I (k1) (2) I + Ac -> An + U (kiAn) (3) I -> Ac + U (kiAc) (4) An -> 2Ac (k2) where Ac is the acid, E is the EDCI, U is the urea, and An is the anhydride. I is the activated intermediate (e.g., O-acylisourea or acyl pyridinium). Applying a steady-state approximation in I: K = kiAc/kiAn ””” def kin_sys(concs, t, *ks): Ac, E, U, An = concs k1, K, k2 = ks # Return equations of Ac’, E’, U’, An’ return [ - k1*E*Ac + 2*k2*An + (k1*K*Ac*E)/(K+Ac) - (k1*E*Ac**2)/(K+Ac), - k1*E*Ac, + k1*E*Ac, + (k1*E*Ac**2)/(K+Ac) - k2*An ] return scipy.integrate.odeint(kin_sys, starting_concs, times, args=tuple(ks), mxstep=10000) # Initial guesses for parameters INIT_ks = [0.02, 200, 0.5]

# k1, K, k2

INIT_STARTING_CONCS = [100, 400] # Ac, E optimized BOUNDS = (0, numpy.inf)

# All must be >0

CONST_STARTING_CONCS = [0, 0]

# U, An unoptimized

# Input order and processing order not necessarily the same, as in # script_col[n] = csv_col[SORT_ORDER[n]] SORT_ORDER = [1, 2, 3, 0] # Simulated data to integrate: INTEGRATE = [3] # Labels for the parameters.

S20

PARAMS = [”k1”, ”K”, ”k2”, ”Acid0”, ”EDCI0”] # Labels for the concentrations. LEGEND = [”Acid”, ”EDCI”, ”Urea”, ”Anhydride”] # Lists of list indices for top/bottom plots. TOP_PLOT = [1, 2] BOTTOM_PLOT = [0, 3] elif sys.argv[1] == ”1”: def solved_kin_sys(starting_concs, ks, times): ”””Defines the kinetic model for the monoacid. Follows the 1SS model, but without a steady-state approximation. ””” def kin_sys(concs, t, *ks): Ac, E, U, An, I = concs k1, kiAc, kiAn, k2 = ks # Return the equations for Ac’, E’, U’, An’, I’ return [ - k1*Ac*E - kiAn*I*Ac + kiAc*I + 2*k2*An, - k1*E*Ac, + kiAc*I + kiAn*I*Ac, + kiAn*I*Ac - k2*An, + k1*Ac*E - kiAn*I*Ac - kiAc*I ] return scipy.integrate.odeint(kin_sys, starting_concs, times, args=tuple(ks), mxstep=10000) INIT_ks = [0.02, 0.5, 0.03, 0.05] INIT_STARTING_CONCS = [100, 30] BOUNDS = (0, numpy.inf) CONST_STARTING_CONCS = [0, 0, 0] SORT_ORDER = [1, 4, 3, 0, 2] INTEGRATE = [3] PARAMS = [”k1”, ”kiAc”, ”kiAn”, ”k2”, ”Acid0”, ”EDCI0”] LEGEND = [”Acid”, ”EDCI”, ”Urea”, ”Anhydride”, ”Intermediate”] TOP_PLOT = [1, 2] BOTTOM_PLOT = [0, 3, 4] elif sys.argv[1] == ”2SS”: def solved_kin_sys(starting_concs, ks, times): ”””Defines the kinetic model for the diacid. (1) DAn + E -> In (k1) (2) In -> DAn + U (kiAc) (3) In + DAn -> DAn+m + U (kiL) (4) I0 -> C + U (kiC) (5) DAn+m -> DAn + DAm (k2L) (6) C -> DA0 (k2C)

S21

System above must be translated to the experimentally observed concentrations: Ac (total diacic), L (total linear anhydride), C (total cyclic anhydride), E (EDCI), and U (urea). Applying a steady-state approximation in I. K = kiAc/kiL EM - kiC/kiL ””” def kin_sys(concs, t, *ks): Ac, E, U, L, C = concs k1, K, EM, k2L, k2C = ks p = Ac/(Ac+L) # Approx fraction of diacid that is monomer. # Return the equations for Ac’, E’, U’, L’, C’ return [ - k1*Ac*E/2 + k2L*L + k2C*C + k1*K*Ac*E/(K+Ac+p*EM)/2 - k1*Ac**2*E/(K+Ac+p*EM)/2 - k1*p*EM*Ac*E/(K+Ac+p*EM)/2, - k1*Ac*E, + k1*Ac*E, + k1*Ac**2*E/(K+Ac+p*EM) - k2L*L, + k1*p*EM*Ac*E/(K+Ac+p*EM) - k2C*C ] return scipy.integrate.odeint(kin_sys, starting_concs, times, args=tuple(ks), mxstep=10000) INIT_ks = [0.02, 100, 10, 0.5, 1] INIT_STARTING_CONCS = [50, 400] BOUNDS = (0, numpy.inf) CONST_STARTING_CONCS = [0, 0, 0] SORT_ORDER = [2, 3, 4, 0, 1] INTEGRATE = [3,4] PARAMS = [”k1”, ”K”, ”EM”, ”k2L”, ”k2C”, ”Acid0”, ”EDCI0”] LEGEND = [”Acid”, ”EDCI”, ”Urea”, ”Linear”, ”Cyclic”] TOP_PLOT = [1, 2] BOTTOM_PLOT = [0, 3, 4] # Constants used elsewhere in script NUM_concs = len(SORT_ORDER)

# Number of experimentally observed concs

NUM_ks = len(INIT_ks)

# Number of rate constants

NUM_params = NUM_ks + len(INIT_STARTING_CONCS) # Total number of parameters # Parameters and settings for plots. SMOOTH_POINTS_PLOT = 1000

# Number of points in simulated plots

SMOOTH_EXTENSION_PLOT = 1.1 # Expansion factor for time axis COLORS = [’b’,’g’,’r’,’c’,’m’,’y’,’k’]

S22

MARKER_SIZE = 6 rcParams[’font.size’] = 6 rcParams[’font.family’] = ’sans-serif’ rcParams[’font.sans-serif’] = [’Arial’] rcParams[’lines.linewidth’] = 0.5 rcParams[’axes.linewidth’] = 0.5 rcParams[’legend.frameon’] = False rcParams[’legend.fontsize’] = 6 plt.figure(figsize=(2.2,3.5)) # Settings for output file SMOOTH_POINTS_OUT = 3000

# Number of points in output curves

SMOOTH_EXTENSION_OUT = 3

# Expansion factor for time axis

# Prevent line breaking and format numbers in correlation matrix numpy.set_printoptions(linewidth=numpy.nan) numpy.set_printoptions(precision=2,suppress=True) # Longest parameter label LEN_params = max([len(n) for n in PARAMS])

def residual(pars, consts, times, exp_concs): ”””Calculates the residuals (as a numpy array) at a given time for a given set of parameters, passed as a list. The list of parameters (pars) begins with the rate constants and ends with the starting concentrations. The list of constants (consts) represents initial concentrations that will not be optimized. Residuals are weighted as 1/(0.1*exp_val) (i.e., according to expected error on NMR measurement). Maximum weighting factor is 2, equivalent to 1/(0.1*5) (i.e., 5 mM signal). ””” ks = pars[:NUM_ks] start_concs = numpy.append(pars[NUM_ks:], consts) calcd_concs = solved_kin_sys(start_concs, ks, times) residuals = [] # List of residuals. for n,r in itertools.product(range(len(times)), range(NUM_concs)): # Ignores values for which there is no experimental data point. if not numpy.isnan(exp_concs[n][r]): residuals.append(((float(exp_concs[n][r]) calcd_concs[n][r]))*min(numpy.divide(1,0.1*float(exp_concs[n][r])), 2)) # Print the sum of squares of the residuals to STDOUT, for the # purpose of monitoring progress.

S23

print(sum([n**2 for n in residuals])) return numpy.array(residuals)

def get_raw_data(raw_data_file): ”””Load data from file, formated as a csv file. The file is assumed to include a header row, and the order of columns must match that specified by the SORT_ORDER list. Returns the times (numpy array), data (numpy array), and total number of data points (int) ””” with open(raw_data_file) as datafile: next(datafile)

# Skip header

ts = []

# List of experimental times

raw_data = []

# List of lists of experimental concentrations

total_points = 0

# Total number of experimental points

for line in datafile: curline = line.replace(”\n”, ””).split(’,’) ts.append(float(curline[0])) concs = [] for n in range(NUM_concs): if n+1 < len(curline): if curline[n+1] != ’’: total_points += 1 concs.append(float(curline[n+1])) else: concs.append(numpy.nan) else: concs.append(numpy.nan) raw_data.append(concs) unsorted_data = numpy.array(raw_data) sorted_data = numpy.empty_like(unsorted_data) for n in range(NUM_concs): sorted_data[:,n] = unsorted_data[:,SORT_ORDER[n]] return numpy.array(ts), sorted_data, total_points

if __name__ == ’__main__’: # Get data from input file. times, exp_concs, total_points = get_raw_data(raw_data_file)

S24

# Perform the actual optimization by least squares minimization of # the residuals. results = least_squares(residual, INIT_ks + INIT_STARTING_CONCS, bounds=BOUNDS, args=(CONST_STARTING_CONCS, times, exp_concs)) # Predictions of optimized model at each experimental time point. predicted_data = solved_kin_sys(numpy.append(results[’x’][NUM_ks:], CONST_STARTING_CONCS), results[’x’][:NUM_ks], times) # Generate smoothed curves with optimized parameters. # For output txt file: smooth_ts_out, deltaT = numpy.linspace(0, max(times)*SMOOTH_EXTENSION_OUT, SMOOTH_POINTS_OUT, retstep=True) smooth_curves_out = solved_kin_sys(numpy.append(results[’x’][NUM_ks:], CONST_STARTING_CONCS), results[’x’][:NUM_ks], smooth_ts_out) # For plots: smooth_ts_plot = numpy.linspace(0, max(times)*SMOOTH_EXTENSION_PLOT, SMOOTH_POINTS_PLOT) smooth_curves_plot = solved_kin_sys(numpy.append(results[’x’][NUM_ks:], CONST_STARTING_CONCS), results[’x’][:NUM_ks], smooth_ts_plot) # Various fitting data. # Sum squared residuls. sum_squares_errors = sum(results[’fun’]*results[’fun’]) # Degrees of freedom dof = total_points - NUM_params # Integrals integrals = {} for n in INTEGRATE: integrals[n] = sum(smooth_curves_out[:,n]) * deltaT # Write the data to output txt file. with open(”{}_{}.txt”.format(raw_data_file, sys.argv[1]), ’w’) as write_file: print(”**Regression results for file \”{}\”**”.format( raw_data_file), file=write_file) print(file=write_file) print(”Python version: {}”.format(platform.python_version()), file=write_file) print(”Numpy version: {}”.format(numpy.version.version), file=write_file)

S25

print(”Scipy version: {}”.format(scipy.version.version), file=write_file) print(file=write_file) print(”Optimized parameters”, file=write_file) print(”====================”, file=write_file) for n in range(len(results[’x’])): print(”{:>{l}} = {:+5e}”.format( PARAMS[n], results[’x’][n], l=LEN_params), file=write_file) print(file=write_file) print(”Integrals”, file=write_file) print(”=========”, file=write_file) for n in INTEGRATE: print(”{}: {:+5e}”.format(LEGEND[n], integrals[n]), file=write_file) print(file=write_file) print(”Regression info”, file=write_file) print(”===============”, file=write_file) print(”Success: {}”.format(results[’success’]), file=write_file) print(”Msg: {}”.format(results[’message’]), file=write_file) print(”Total points (dof): {} ({})”.format(total_points, dof), file=write_file) print(”Std Deviation of errors: {}”.format( numpy.sqrt(sum_squares_errors/dof)), file=write_file) print(”Sum square errors: {}”.format( sum_squares_errors), file=write_file) print(file=write_file) print(”Results”, file=write_file) print(”=======”, file=write_file) print(”t”, end=” ”, file=write_file) for l in LEGEND: print(l, end=” ”, file=write_file) print(file=write_file) for n in range(len(smooth_ts_out)): print(smooth_ts_out[n], end=” ”, file=write_file) for m in smooth_curves_out[n]: print(m, end=” ”, file=write_file) print(file=write_file) # Plot the data and save as pdf. plt.subplot(211) col = 0 for n in [numpy.array(exp_concs).T[n] for n in TOP_PLOT]: plt.scatter(times, n, c=COLORS[col], s=MARKER_SIZE, linewidths=0) col += 1 col = 0 for n in [smooth_curves_plot.T[n] for n in TOP_PLOT]:

S26

plt.plot(smooth_ts_plot, n, COLORS[col] + ’-’) col += 1 plt.legend([LEGEND[n] for n in TOP_PLOT], loc=4) plt.ylim(ymin=0) plt.xlim(xmin=0, xmax=smooth_ts_plot[-1]) plt.ylabel(”C (mM)”) # Print parameters on plot. pars_to_print = ”” for n in range(len(results[’x’])): pars_to_print += ”{} = {:.2e}\n”.format(PARAMS[n], results[’x’][n]) plt.text(0.5, 0.2, pars_to_print, transform=plt.gca().transAxes, fontsize=6) plt.subplot(212) col = 0 for n in [numpy.array(exp_concs).T[n] for n in BOTTOM_PLOT]: plt.scatter(times, n, c=COLORS[col], s=MARKER_SIZE, linewidths=0, zorder=2) col += 1 col = 0 for n in [smooth_curves_plot.T[n] for n in BOTTOM_PLOT]: plt.plot(smooth_ts_plot, n, COLORS[col] + ’-’, zorder=3) col += 1 plt.legend([LEGEND[n] for n in BOTTOM_PLOT], loc=2) plt.ylim(ymin=0) plt.xlim(xmin=0, xmax=smooth_ts_plot[-1]) plt.xlabel(’t (min)’) plt.ylabel(’C (mM)’) plt.tight_layout() plt.savefig(raw_data_file + ”_{}.pdf”.format(sys.argv[1]))

Raw kinetic data Note: Some of the fits show systematic deviations that likely reflect variations in pH and temperature that are not accounted for in the simplified kinetic models.

S27

Figure S26. Monitoring of assembly of KSB-An. Solid lines are the best fits to the kinetic model.

Figure S27. Monitoring of assembly of MEA-An, without added salt. Solid lines are the best fits to the kinetic model.

S28

Figure S28. Monitoring of assembly of MEA-An, with 1 M LiCl. Solid lines are the best fits to the kinetic model.

Figure S29. Monitoring of assembly of MEA-An, with 1 M NaCl. Solid lines are the best fits to the kinetic model.

S29

Figure S30. Monitoring of assembly of MEA-An, with 1 M KCl. Solid lines are the best fits to the kinetic model.

Figure S31. Monitoring of assembly of MEA-An, with 1 M CsCl. Solid lines are the best fits to the kinetic model.

S30

Figure S32. Monitoring of assembly of TEG-Cy, with 1 M LiCl. Solid lines are the best fits to the kinetic model.

Figure S33. Monitoring of assembly of TEG-Cy, with 1 M NaCl. Solid lines are the best fits to the kinetic model.

S31

Figure S34. Monitoring of assembly of TEG-Cy, with 1 M KCl. Solid lines are the best fits to the kinetic model.

Figure S35. Monitoring of assembly of TEG-Cy, with 1 M CsCl. Solid lines are the best fits to the kinetic model.

S32

Figure S36. Monitoring of assembly of PEG-Cy, with 1 M LiCl. Solid lines are the best fits to the kinetic model.

Figure S37. Monitoring of assembly of PEG-Cy, with 1 M NaCl. Solid lines are the best fits to the kinetic model.

S33

Figure S38. Monitoring of assembly of PEG-Cy, with 1 M KCl. Solid lines are the best fits to the kinetic model.

Figure S39. Monitoring of assembly of PEG-Cy, with 1 M CsCl. Solid lines are the best fits to the kinetic model.

Calculated geometries TEG-Cy (B3LYP/6-31G(d)) --------------------------------------------------------------------Center

Atomic

Atomic

Number

Number

Type

Coordinates (Angstroms) X

Y

Z

S34

--------------------------------------------------------------------1

6

0

-1.042692

-2.165139

-2.043552

2

1

0

-1.082960

-3.011364

-2.747538

3

1

0

-2.056330

-2.051400

-1.619099

4

6

0

-0.286686

-3.526665

-0.280925

5

1

0

-1.326196

-3.586716

0.077628

6

1

0

-0.085717

-4.419278

-0.897289

7

6

0

0.651577

-3.496855

0.910398

8

1

0

1.647524

-3.179005

0.565563

9

1

0

0.748516

-4.512001

1.332960

10

6

0

1.102839

-2.104950

2.773151

11

1

0

1.533122

-2.918033

3.384872

12

1

0

1.926424

-1.621464

2.224334

13

6

0

0.452573

-1.090793

3.694722

14

1

0

1.200555

-0.769225

4.440832

15

1

0

-0.384693

-1.558183

4.240481

16

6

0

-0.452573

1.090793

3.694722

17

1

0

-1.200555

0.769225

4.440832

18

1

0

0.384693

1.558183

4.240481

19

6

0

-1.102839

2.104950

2.773151

20

1

0

-1.533122

2.918033

3.384872

21

1

0

-1.926424

1.621464

2.224334

22

6

0

-0.651577

3.496855

0.910398

23

1

0

-1.647524

3.179005

0.565563

24

1

0

-0.748516

4.512001

1.332960

25

6

0

0.286686

3.526665

-0.280925

26

1

0

1.326196

3.586716

0.077628

27

1

0

0.085717

4.419278

-0.897289

28

6

0

1.042692

2.165139

-2.043552

29

1

0

1.082960

3.011364

-2.747538

30

1

0

2.056330

2.051400

-1.619099

31

8

0

0.000000

0.000000

-2.197203

32

8

0

0.082049

2.345890

-1.040520

33

8

0

-0.135168

2.599369

1.871333

34

8

0

0.000000

0.000000

2.924274

35

8

0

0.135168

-2.599369

1.871333

36

8

0

-0.082049

-2.345890

-1.040520

37

6

0

0.764026

0.925514

-2.878866

38

6

0

-0.764026

-0.925514

-2.878866

39

8

0

1.239755

0.744030

-3.965359

40

8

0

-1.239755

-0.744030

-3.965359

---------------------------------------------------------------------

S2 (B3LYP/6-31G(d)) --------------------------------------------------------------------Center

Atomic

Atomic

Number

Number

Type

Coordinates (Angstroms) X

Y

Z

--------------------------------------------------------------------1

6

0

-18.776651

-1.266893

0.195625

2

1

0

-18.832169

-1.535878

1.262695

S35

3

1

0

-18.730777

-2.211997

-0.369363

4

6

0

-15.339477

-0.053112

-0.100229

5

1

0

-15.392506

0.212737

-1.167424

6

1

0

-15.476423

0.870446

0.483374

7

8

0

-21.123115

-1.322288

0.088513

8

1

0

-21.922297

-0.825143

-0.172299

9

6

0

-20.055508

-0.544358

-0.185059

10

8

0

-20.133968

0.563644

-0.665978

11

6

0

-11.730678

-0.620995

0.282787

12

1

0

-11.689205

-1.549471

-0.307787

13

1

0

-11.751108

-0.901213

1.347514

14

6

0

-8.276647

0.578271

-0.068399

15

1

0

-8.396242

1.498125

0.524807

16

1

0

-8.347436

0.853138

-1.132261

17

6

0

-16.438499

-1.049472

0.239860

18

1

0

-16.394769

-1.309351

1.308492

19

1

0

-16.298780

-1.975219

-0.338858

20

6

0

-12.986578

0.162292

-0.072183

21

1

0

-13.030182

1.090154

0.519100

22

1

0

-12.964033

0.443246

-1.136580

23

6

0

-9.376120

-0.413474

0.284151

24

1

0

-9.253512

-1.334248

-0.307207

25

1

0

-9.308600

-0.686874

1.348727

26

8

0

-17.678807

-0.435763

-0.080600

27

8

0

-14.100870

-0.668222

0.207189

28

8

0

-10.617207

0.208678

-0.000489

29

8

0

-7.033802

-0.044515

0.210121

30

6

0

-5.923191

0.781103

-0.091897

31

1

0

-5.950387

1.710370

0.497973

32

1

0

-5.917383

1.059075

-1.157228

33

6

0

-4.666133

-0.008766

0.242772

34

1

0

-4.662801

-0.280994

1.308814

35

1

0

-4.637405

-0.938253

-0.345251

36

8

0

-3.553556

0.820238

-0.069282

37

6

0

-2.325896

0.195855

0.193139

38

1

0

-2.193158

-0.728866

-0.390817

39

1

0

-2.215971

-0.079831

1.255175

40

8

0

-0.000015

0.481944

-0.000101

41

6

0

-1.206461

1.152350

-0.159900

42

8

0

-1.313730

2.280938

-0.548077

43

6

0

2.325878

0.195519

-0.192666

44

1

0

2.216253

-0.081307

-1.254439

45

1

0

2.192877

-0.728555

0.392248

46

6

0

4.666110

-0.009200

-0.241855

47

1

0

4.662992

-0.282073

-1.307734

48

1

0

4.637191

-0.938329

0.346722

49

6

0

5.923156

0.780782

0.092593

50

1

0

5.917293

1.059175

1.157812

51

1

0

5.950398

1.709816

-0.497644

52

6

0

8.276611

0.577852

0.069416

S36

53

1

0

8.347425

0.852768

1.133264

54

1

0

8.396171

1.497681

-0.523834

55

6

0

9.376089

-0.413886

-0.283140

56

1

0

9.308572

-0.687255

-1.347724

57

1

0

9.253479

-1.334678

0.308191

58

6

0

11.730655

-0.621294

-0.282077

59

1

0

11.751019

-0.901195

-1.346888

60

1

0

11.689256

-1.549946

0.308224

61

6

0

12.986554

0.161936

0.073022

62

1

0

12.964158

0.442465

1.137534

63

1

0

13.029999

1.090036

-0.517898

64

6

0

1.206428

1.152524

0.158952

65

8

0

1.313686

2.281633

0.545615

66

8

0

3.553521

0.820071

0.069441

67

8

0

7.033770

-0.044969

-0.209044

68

8

0

10.617175

0.208258

0.001518

69

8

0

14.100861

-0.668387

-0.206860

70

6

0

15.339472

-0.053298

0.100587

71

1

0

15.392710

0.212034

1.167900

72

1

0

15.476191

0.870560

-0.482594

73

6

0

16.438525

-1.049371

-0.240246

74

1

0

16.394567

-1.308730

-1.308995

75

1

0

16.299052

-1.975417

0.338051

76

6

0

18.776715

-1.266525

-0.196748

77

1

0

18.831952

-1.534970

-1.263968

78

1

0

18.731130

-2.211918

0.367781

79

8

0

17.678842

-0.435678

0.080214

80

8

0

21.123219

-1.321650

-0.090394

81

1

0

21.922411

-0.824524

0.170421

82

6

0

20.055589

-0.544011

0.183919

83

8

0

20.134046

0.563749

0.665394

---------------------------------------------------------------------

K+ ⊂ 18-Crown-6 (B3LYP/6-31+G(d,p)) --------------------------------------------------------------------Center

Atomic

Atomic

Number

Number

Type

Coordinates (Angstroms) X

Y

Z

--------------------------------------------------------------------1

6

0

1.192226

3.452321

0.301637

2

1

0

1.203105

4.509227

-0.002467

3

1

0

1.239942

3.407880

1.399724

4

6

0

-1.192333

3.452407

0.301643

5

1

0

-1.240081

3.407868

1.399725

6

1

0

-1.203127

4.509333

-0.002380

7

6

0

-2.394688

2.759221

-0.302075

8

1

0

-2.333700

2.779541

-1.400206

9

1

0

-3.303745

3.297548

0.003675

10

6

0

-3.587342

0.693769

-0.302372

11

1

0

-4.508040

1.212736

0.002044

12

1

0

-3.573561

0.629654

-1.400434

13

6

0

3.587342

-0.693769

0.302372

S37

14

1

0

3.573561

-0.629654

1.400434

15

1

0

4.508040

-1.212736

-0.002044

16

6

0

2.394688

-2.759221

0.302075

17

1

0

3.303745

-3.297548

-0.003675

18

1

0

2.333700

-2.779541

1.400206

19

6

0

1.192333

-3.452407

-0.301643

20

1

0

1.203127

-4.509333

0.002380

21

1

0

1.240081

-3.407868

-1.399725

22

6

0

-1.192226

-3.452321

-0.301637

23

1

0

-1.239942

-3.407880

-1.399724

24

1

0

-1.203105

-4.509227

0.002467

25

6

0

-2.394572

-2.759071

0.302024

26

1

0

-2.333594

-2.779319

1.400156

27

1

0

-3.303619

-3.297437

-0.003682

28

6

0

-3.587278

-0.693691

0.302341

29

1

0

-4.507983

-1.212715

-0.001935

30

1

0

-3.573355

-0.629543

1.400399

31

8

0

2.442229

1.409461

0.162057

32

8

0

-2.442229

-1.409461

-0.162057

33

8

0

0.000079

-2.818813

0.163433

34

8

0

2.442269

-1.409577

-0.161894

35

8

0

-2.442269

1.409577

0.161894

36

8

0

-0.000079

2.818813

-0.163433

37

6

0

2.394572

2.759071

-0.302024

38

1

0

3.303619

3.297437

0.003682

39

1

0

2.333594

2.779319

-1.400156

40

6

0

3.587278

0.693691

-0.302341

41

1

0

3.573355

0.629543

-1.400399

42

1

0

4.507983

1.212715

0.001935

43

19

0

0.000000

0.000000

0.000000

---------------------------------------------------------------------

K+ ⊂ TEG-Cy (B3LYP/6-31+G(d,p)) --------------------------------------------------------------------Center

Atomic

Atomic

Number

Number

Type

Coordinates (Angstroms) X

Y

Z

--------------------------------------------------------------------1

6

0

-0.392403

2.421046

-2.357928

2

1

0

-1.184436

2.854125

-2.986892

3

1

0

0.431904

3.147291

-2.321148

4

6

0

-1.250419

3.308715

-0.334793

5

1

0

-0.353681

3.906417

-0.121246

6

1

0

-1.940856

3.914010

-0.938159

7

6

0

-1.948515

2.921983

0.952583

8

1

0

-2.837240

2.310377

0.733724

9

1

0

-2.282246

3.840585

1.456636

10

6

0

-1.615018

1.790991

3.031152

11

1

0

-1.972005

2.665693

3.593744

12

1

0

-2.474005

1.127404

2.847546

13

6

0

-0.564811

1.070192

3.856743

14

1

0

-1.042385

0.708921

4.777473

S38

15

1

0

0.251873

1.752483

4.128820

16

6

0

0.596272

-1.059186

3.845068

17

1

0

1.060940

-0.652431

4.752736

18

1

0

-0.151306

-1.807391

4.139669

19

6

0

1.688575

-1.690985

3.000749

20

1

0

2.134253

-2.525613

3.561340

21

1

0

2.479971

-0.954733

2.793119

22

6

0

2.088791

-2.804936

0.928549

23

1

0

2.922693

-2.121323

0.708772

24

1

0

2.498035

-3.695142

1.427930

25

6

0

1.421245

-3.241170

-0.359294

26

1

0

0.578360

-3.914031

-0.149768

27

1

0

2.158787

-3.781325

-0.968542

28

6

0

0.524963

-2.389614

-2.388276

29

1

0

1.367852

-2.734919

-3.006224

30

1

0

-0.234979

-3.183310

-2.394162

31

8

0

0.010695

0.005483

-2.399734

32

8

0

0.950073

-2.085165

-1.071401

33

8

0

1.132621

-2.159728

1.769716

34

8

0

-0.042530

-0.021288

3.094546

35

8

0

-1.043873

2.198157

1.785756

36

8

0

-0.877248

2.124550

-1.059676

37

19

0

-0.127243

-0.060646

0.426776

38

6

0

-0.078244

-1.198918

-3.115018

39

6

0

0.131552

1.207870

-3.108018

40

8

0

0.642321

1.286570

-4.185068

41

8

0

-0.612259

-1.289740

-4.179132

---------------------------------------------------------------------

References (1)

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