Olsalazine-Based Metal–Organic Frameworks As Biocompatible Platforms for H2 Adsorption and Drug Delivery

Supporting Information for:

Olsalazine-Based Metal–Organic Frameworks as Biocompatible Platforms for H2 Adsorption and Drug Delivery

Dana J. Levine, Tomče Runčevski, Matthew T. Kapelewski, Benjamin K. Keitz, Julia Oktawiec, Douglas A. Reed, Jarad A. Mason, Henry Z. H. Jiang, Kristen A. Colwell, Christina Legendre, Stephen A. FitzGerald, Jeffrey R. Long*

* Email: [email protected]

Journal of the American Chemical Society

Table of Contents

I. Synthesis and Characterization Scheme S1. Synthesis of olsalazine acid (H4olz) ...... S3 Figure S1. Scanning electron microscopy of M2(olz) crystallites ...... S4

II. Powder X-Ray Diffraction Figure S2. Structural comparison of the isoreticular MOF-74 frameworks M2(dobdc), M2(dobpdc), and M2(olz) ...... S5 Figure S3. Rietveld refinement of Mg2(olz) ...... S6 Figure S4. Structural model of the M2(olz) frameworks ...... S7 Table S1. Pawley fitting of M2(olz) unit cell parameters ...... S7 Figures S5-9. Pawley fits for M2(olz) frameworks ...... S8

III. N2 Adsorption Isotherms and Surface Area Calculations Figure S10. N2 adsorption isotherms at 77 K in M2(olz) frameworks ...... S10 Figures S11-15. Linear plots for M2(olz) BET calculations ...... S11

IV. H2 Adsorption Isotherms Equations S1-4. Langmuir-Freundlich equations and Clausius-Clapeyron relation for calculation of isosteric heats of adsorption ...... S14 Table S2. Langmuir fit parameters for M2(olz) H2 isotherms ...... S14 Figures S16-20. H2 adsorption isotherms at 77 K and 87 K in M2(olz) ...... S15 Figure S21. Crystallinity changes in Zn2(olz) upon activation ...... S17

V. Thermogravimetric Analysis Figure S22. Thermogravimetric analysis of M2(olz) frameworks ...... S18

VI. In Situ Infrared Spectroscopy Figure S23. Energy diagram of H2 explaining the vibrational transitions observed in metal–organic frameworks ...... S19 Figure S24. H2 adsorption at multiple binding sites in Mg2(olz) ...... S20 Figure S25. H2 adsorption at open metal site of Mg2(olz) ...... S21 Figure S26. Comparison of H2 adsorption at the open metal site of M2(dobdc) and M2(olz) (M = Mg, Ni) ...... S22

VII. Drug Loading and Release in Mg2(olz) Figure S27. Olsalazine release from Mg2(olz) ...... S23 Figure S28. Phenethylamine derivatives of pharmaceutical importance ..... S24 1 Figure S29. Stoichiometry of Mg2(olz)(PEA)2 by H NMR ...... S25 1 Figure S30. Stoichiometry of Mg2(olz)(Me-PEA)2 by H NMR ...... S26 Figure S31. IR spectra of PEA, Mg2(olz), and Mg2(olz)(PEA)2 ...... S27

I. Synthesis and Characterization

Scheme S1. Synthesis of olsalazine acid (H4olz).

O O O

NH2 NH2 NO HO O ® O H2SO4, MeOH Oxone

HO 75-80 ºC HO DCM/H2O HO 1 2 3

O NH OH OH O 2 O O

HO N O NaOH, 90-95ºC N OH O N HO N acetic acid O then HCl O HO HO 4 H4olz

Methyl 5-aminosalicylate (2). 5-Amino salicylic acid (1, 20.0 g, 131 mmol) was suspended in methanol (250 mL). Concentrated sulfuric acid (10 mL) was added, and the solution was heated to reflux (75-80 °C) with stirring. The solution was kept at reflux overnight, then cooled to ambient temperature and concentrated on a rotary evaporator. The resulting pale lavender powder was treated by slow addition of saturated sodium bicarbonate (500 mL). The product was extracted with 3×200 mL portions of ethyl acetate. The organic layers were combined and dried over magnesium sulfate, filtered, then concentrated on a rotary evaporator. The residue was dried under vacuum to give the title compound as a light tan solid (10.7 g, 49.2% yield).

Methyl 5-nitrososalicylate (3). To a solution of compound 2 (3.01 g, 18.0 mmol) in CH2Cl2 (75 mL), a solution of Oxone (11.1 g, 18.0 mmol) in H2O (75 mL) was added. The biphasic mixture was stirred vigorously at room temperature, as the CH2Cl2 layer developed a dark green color. The progression of the reaction was monitored by LCMS until the starting material was fully consumed (usually about two hours). The layers were separated, then the aqueous layer was washed with additional CH2Cl2 (2 × 75 mL). The combined organic layers were filtered through a short silica column, eluting with CH2Cl2. The filtrate was concentrated on a rotary evaporator and dried under vacuum to afford the title compound as a bright green solid (1.69 g). Some over-oxidation of nitroso to nitro was evident by LCMS. However, this did not interfere with the subsequent reaction, and the crude mixture was used in the next step without further purification.

Olsalazine methyl ester (4). The crude mixture obtained from the previous step was dissolved in acetic acid (35 mL). To this was added a solution of 2 (1.50 g, 9 mmol) in acetic acid (35 mL). The reaction mixture was stirred at room temperature overnight. The resulting precipitate was collected on a Buchner funnel and washed sequentially with acetic acid and water to afford 4 as a bright yellow solid (1.78 g, 29.9% yield, two steps).

Olsalazine acid (H4olz). Compound 4 (1.75 g, 5.30 mmol) was dissolved in 50 mL aqueous NaOH (1.06 g, 26.5 mmol). The deep red solution was heated to reflux (90-95 °C) with stirring. After 2 h, the reaction mixture was allowed to cool to ambient temperature. Concentrated HCl was added dropwise with stirring until no further precipitation occurred. The precipitate was collected on a Buchner funnel, washed with water, and dried to afford H4(olz) as an orange-yellow solid (1.492 g, 97.6%).

Figure S1. Scanning electron microscopy images of M2(olz) crystallites (from top to bottom: Mg, Fe, Co, Ni, Zn; left column scale bars = 2 µm, right column scale bars = 1 µm). Images were taken using a JEOL JSM- 6340F SEM. Samples were suspended in methanol and drop cast onto a silicon chip. To dissipate charge, the samples were sputter coated with approximately 3 nm of Au (Denton Vacuum).

II. Powder X-Ray Diffraction

Figure S2. Comparison of isoreticular MOF-74 frameworks (a) M2(dobdc), (b) M2(dobpdc), and (c) M2(olz). Left: structures of fully protonated ligands. Center: experimental powder X-ray diffraction patterns of Zn frameworks (λ = 1.5418 Å). Right: structural representations of desolvated frameworks with pore sizes indicated. Cyan, grey, red, and blue spheres correspond to metal, carbon, oxygen, and nitrogen atoms, respectively. Hydrogen atoms omitted for clarity.

2θ (°)

Figure S3. The observed scattered intensity for Mg2(olz) is presented with blue circles, the best fit with a red line, and the difference plot with a gray line (λ = 0.414187 Å). The Bragg positions are given with vertical blue lines. During the refinement, the lattice and profile parameters were varied. Due to the poor quality of the diffraction data (only few reflections are observed, none of which corresponding to the c-axis), the structural model could not be refined. The model of the crystal structure was not refined and used as constructed in TOPAS (Figure S4), based on the related structure of Mg2(dobpdc). The Rietveld refinement converged with the following figures of merit: Rexp = 0.0686, Rexp' = 0.1964, Rwp = 0.0821, Rwp' = 0.2352, Rp = 0.0643, Rp' = 0.2659, GOF = 1.98. The crystal structure was described in the P3221 space group and the resulting unit cell parameters are a = 24.88(7) Å and c = 6.49(5) Å.

Figure S4. Structural model of M2(olz) viewed down c-axis. Cyan, grey, red, and blue spheres correspond to metal, carbon, oxygen, and nitrogen atoms, respectively. Hydrogen atoms omitted for clarity.

Table S1. Pawley Fitting of the Unit Cell Parameters for M2(olz) Frameworks from Powder X-Ray Diffraction.

Mg2(olz) Fe2(olz) Co2(olz) Ni2(olz) Zn2(olz)⋅EtOHx λ / Å 0.72768 0.72768 0.72768 0.72768 0.72768 T / K 273 273 273 273 273

Space group P3221 P3221 P3221 P3221 P3221 a / Å 24.97(5) 25.03(4) 24.81(5) 24.91(4) 25.42(6) c / Å 6.72(4) 6.53(7) 6.63(5) 6.65(7) 6.84(6) V / Å3 3629(2) 3543(4) 3534(3) 3570(4) 3824(3)

Rexp 1.312 0.877 1.688 1.228 1.400

Rwp 2.928 4.042 3.563 3.766 3.211

Rp 2.089 2.507 2.020 2.695 2.040

2θ (°)

Figure S5. Pawley fit for Mg2(olz) showing the observed (blue) and fitted (red) powder X-ray diffraction patterns and the difference (grey) (λ = 0.72768 Å).

2θ (°)

Figure S6. Pawley fit for Fe2(olz) showing the observed (blue) and fitted (red) powder X-ray diffraction patterns and the difference (grey) (λ = 0.72768 Å).

2θ (°)

Figure S7. Pawley fit for Co2(olz) showing the observed (blue) and fitted (red) powder X-ray diffraction patterns and the difference (grey) (λ = 0.72768 Å).

2θ (°)

Figure S8. Pawley fit for Ni2(olz) showing the observed (blue) and fitted (red) powder X-ray diffraction patterns and the difference (grey) (λ = 0.72768 Å).

2θ (°)

Figure S9. Pawley fit for ethanol-solvated Zn2(olz) showing the observed (blue) and fitted (red) powder X-ray diffraction patterns and the difference (grey) (λ = 0.72768 Å).

III. N 2 Adsorption Isotherms and Surface Area Calculations

Co 40 Ni

30 Fe

20 Adsorbed (mmol/g) 2 N 10 Zn

0 0 200 400 600 800 1000 P (mbar)

Figure S10. Isotherms for the adsorption of N2 at 77 K in activated M2(olz) (From top: M = Mg, Co, Ni, Fe, Zn).

S10

0.0025 y = 0.03824x + 0.00008 R² = 0.99872 0.002 )] o

0.0015 ) / [n(1–P/P

o 0.001 (P/P 0.0005

Mg 0 0 0.01 0.02 0.03 0.04 0.05 0.06

P/Po

Figure S11. Linear plot for Mg2(olz) BET calculation.

0.004 y = 0.06568x + 0.00012 0.0035 R² = 0.99870

)] 0.003 o

0.0025

0.002 ) / [n(1–P/P o 0.0015

(P/P 0.001

0.0005 Fe 0 0 0.01 0.02 0.03 0.04 0.05 0.06 P/Po

Figure S12. Linear plot for Fe2(olz) BET calculation.

S11

0.0014 y = 0.04729x + 0.00006 0.0012 R² = 0.99953 )] o 0.001

0.0008

) / [n(1–P/P 0.0006 o

(P/P 0.0004

0.0002 Co 0 0 0.005 0.01 0.015 0.02 0.025 0.03 P/Po

Figure S13. Linear plot for Co2(olz) BET calculation.

0.0014 y = 0.04713x + 0.00006 0.0012 R² = 0.99950 )] o 0.001

0.0008

) / [n(1–P/P 0.0006 o

(P/P 0.0004

0.0002 Ni 0 0 0.005 0.01 0.015 0.02 0.025 0.03 P/Po

Figure S14. Linear plot for Ni2(olz) BET calculation.

S12

0.018 y = 0.1527x + 0.0006 0.016 R² = 0.99957 0.014 )] o 0.012

0.01

0.008 ) / [n(1–P/P o 0.006 (P/P 0.004

0.002 Zn 0 0 0.02 0.04 0.06 0.08 0.1 0.12 P/Po

Figure S15. Linear plot for Zn2(olz) BET calculation.

S13

IV. H2 Adsorption Isotherms

The dual-site Langmuir−Freundlich expression (Equation S1) was used to fit the combined isotherm data at 77 K and 87 K for Mg2(olz), Fe2(olz), Ni2(olz), and Zn2(olz). The tri-site Langmuir expression (Equation S2) was used to fit the data for Co2(olz), where n is the amount of gas adsorbed (mmol/g), qsat is the saturation loading for site 1, 2, or 3 (mmol/g), b is the Langmuir parameter associated with either site 1, 2, or 3 (bar–v), p is the pressure, and v is a constant. The value for b is calculated per Equation S3.

Equation S1 , , 𝑞𝑞 𝑏𝑏 𝑝𝑝 𝑞𝑞 𝑏𝑏 𝑝𝑝 𝑛𝑛 = + 1 + 𝑏𝑏𝑝𝑝 1 + 𝑏𝑏𝑝𝑝 Equation S2 𝑞𝑞,𝑏𝑏𝑝𝑝 𝑞𝑞,𝑏𝑏𝑝𝑝 𝑞𝑞,𝑏𝑏𝑝𝑝 𝑛𝑛 = + + 1 + 𝑏𝑏𝑝𝑝 1 + 𝑏𝑏𝑝𝑝 1 + 𝑏𝑏𝑝𝑝 Equation S3 – ∙ The equation was fit using the statistical𝑏𝑏 = 𝑒𝑒 software𝑒𝑒 package of OriginPro 8. . The quality of fits was determined by comparing the adjusted R2 and residual sum of squares uares values, as well as by visual inspection. Wolfram Mathematica 7 was then used to create reate a series of data points corresponding to points on the fit curve. The isosteric heat off adsorption Qst was then calculated using the data points from Mathematica for both the 77 K and 87 K isotherms using the Clausius-Clapeyron relation (Equation S4) at equivalent ent loadings (n, mmol/g). Qst is the isosteric heat of adsorption (kJ/mol), R is the e gas constant (L*bar/[mol*K]), and P is the pressure at a given n at either T2 (87 K) or T1 (77 K).

Equation S4 𝑅𝑅 ln(𝑃𝑃) − ln(𝑃𝑃) 𝑄𝑄 = − 𝑇𝑇 − 𝑇𝑇 Table S2. Dual and tri-site Langmuir fit parameters for the H2 isotherms for M (olz) in Figures S16-S20. 2 Mg2(olz) Fe2(olz) Co2(olz) Ni2(olz) Zn2(olz) qsat,1 (mmol/g) 4.36 2.66 4.19 4.04 0.74 S1 (R) 9.57 10.52 10.28 9.96 8.86 E1 (kJ/mol) 10.29 10.38 11.63 12.10 8.04 v1 0.95 1 1.03 1 1 qsat,2 (mmol/g) 29.14 21.52 20.49 14.06 4.72 S2 (R) 7.46 10.07 6.94 7.92 7.01 E2 (kJ/mol) 3.88 5.50 3.62 4.73 4.56 v2 0.86 0.76 0.97 1 1 qsat,3 (mmol/g) – – 1.53 – – S3 (R) – – 16.38 – – E3 (kJ/mol) – – 11.05 – – v3 – – 0.62 – –

S14

Mg 10

4 Adsorbed (mmol/g) 2 H 2 77 K 0 87 K 0 200 400 600 800 1000 1200 Absolute Pressure (mbar)

Figure S16. H2 adsorption isotherms at 77 K and 87 K for Mg2(olz) . The solid lines represent the simultaneous dual-site Langmuir fit to the data, using the parameters given in Table S2.

Fe 10

4 Adsorbed (mmol/g) 2 H 2 77 K 87 K 0 0 200 400 600 800 1000 1200 Absolute Pressure (mbar)

Figure S17. H2 adsorption isotherms at 77 K and 87 K for Fe2(olz) . The solid lines represent the simultaneous dual-site Langmuir fit to the data, using the parameters given in Table S2.

S15

Co 10

4 Adsorbed (mmol/g) 2 H 2 77 K 0 87 K 0 200 400 600 800 1000 1200 Absolute Pressure (mbar)

Figure S18. H2 adsorption isotherms at 77 K and 87 K for Co2(olz) . The solid lines represent the simultaneous tri-site Langmuir fit to the data, using the parameters given in Table S2.

10 Ni

4 Adsorbed (mmol/g) 2 H 2 77 K 0 87 K 0 200 400 600 800 1000 1200 Absolute Pressure (mbar)

Figure S19. H2 adsorption isotherms at 77 K and 87 K for Ni2(olz) . The solid lines represent the simultaneous dual-site Langmuir fit to the data, using the parameters given in Table S2.

S16

Zn 10

4 Adsorbed (mmol/g) 2 H 2 77 K 0 87 K 0 200 400 600 800 1000 1200 Absolute Pressure (mbar)

Figure S20. H2 adsorption isotherms at 77 K and 87 K for Zn2(olz) . The solid lines represent the simultaneous dual-site Langmuir fit to the data, using the parameters given in Table S2.

Activated,Partially activated 100ºC 20000 Air,Air, then then MeOH MeOH

150001

Activated Zn (olz) 2 100001 ntensity(a.u.) I 5000

0 Zn (olz) in MeOH 4 6 8 10 12 14 16 18 20 2 2θ (º)

Figure S21. Decreased crystallinity of Zn2(olz) after partial activation at 65 °C is regained after exposure to methanol by powder X-ray diffraction (λ = 1.5418 Å). This behavior is suggestive of framework collapse upon desolvation, resulting in loss of long-range order and decreased surface area. When re-immersed in a coordinating solvent such as methanol, crystallinity is restored.

S17

V. Thermogravimetric Analysis

100 100 Mg Co

80 80

60 60 Weight (%) Weight (%) Weight

40 40

20 20 100 200 300 400 500 600 100 200 300 400 500 600 Temperature (ºC) Temperature (ºC)

100 100 Ni Zn

80 80

60 60 Weight (%) Weight (%) Weight

40 40

20 20 100 200 300 400 500 600 100 200 300 400 500 600 Temperature (ºC) Temperature (ºC)

Figure S22. Thermogravimetric analysis (TGA) of air-stable methanol- solvated M2(olz) frameworks. Data collected with a ramp rate of 2 °C/min.

S18

VI. In Situ Infrared Spectroscopy

Figure S23. Energy diagram of molecular hydrogen explaining the vibrational transitions observed in metal–organic frameworks. While gas phase H2 is not observed by IR spectroscopy, the polarization of the molecule upon interaction with a metal cation results in transitions from the vibrational ground state (ν = 0) to the first excited state (ν = 1) for para and ortho-H2. J is the rotational quantum number. The values indicate gas phase transition frequency in cm-1. Dashed vertical arrows indicate transitions that are activated by the overlap mechanism, solid arrows indicate the quadrupole mechanism, and the transition marked with the thick arrow is activated by both. EB0 and EB1 are the binding energies in the ground state and vibrationally excited states, respectively.

S19

Figure S24. H2 adsorbed at multiple binding sites as a function of loading in Mg2(olz). IR absorption of H2 at 15 K, the equivalent number refers to H2 molecules per Mg. The vertical lines show the H2 gas phase wavenumber values for vibration (Q) and vibration-rotation (S) excitations. Q1 translational refers to the center-of-mass motion of the adsorbed H2. Q(0) and S(0) refer to para-H2 and Q(1) to ortho-H2. Subscript 1 indicates fundamental transition in which the vibrational quantum number increases by one.

S20

Figure S25. H2 adsorbed at an open metal site. Curve in red: absorbance at 15 K for one H2 per Mg relative to activated sample of Mg2(olz). Insets: overtone and fundamental stretching vibrations of H2, showing peaks of both ortho and para hydrogen. Curve in black: Raw IR signal for activated Mg2(olz) sample at 15 K.

S21

Mg2(dobdc)

Mg2(olz)

Ni2(dobdc)

Ni2(olz)

Figure S26. IR spectra of H2 adsorbed at an open metal site, recorded at 4– 77 K. Mg2(dobdc), Mg2(olz), Ni2(dobdc), and Ni2(olz) (dobdc = 2,5- dioxido-1,4-benzenedicarboxylate) loaded with one H2 molecule per open metal site. For frameworks composed of the same metal but different organic linker, the similar wavenumber values for the H2 stretching vibrations indicate similar local environment around the metal center. The observed redshifts in the nickel frameworks indicate that H2 is more strongly bound to the nickel open metal sites than the analogous magnesium sites; this is confirmed by the calculated entropy and enthalpy changes upon adsorption. The small difference in the redshift of bound H2 between the dobdc4– and the olz4– analogues is consistent with similar binding energies observed in previously reported plots of isosteric heats of adsorption.1,2

1. Sumida, K.; Brown, C. M.; Herm, Z. R.; Chavan, S.; Bordiga, S.; Long, J. R. Chem. Commun. 2011, 47 (4), 1157. 2. Kapelewski, M. T.; Geier, S. J.; Hudson, M. R.; Stück, D.; Mason, J. A.; Nelson, J. N.; Xiao, D. J.; Hulvey, Z.; Gilmour, E.; FitzGerald, S. A.; Head-Gordon, M.; Brown, C. M.; Long, J. R. J. Am. Chem. Soc. 2014, 136 (34), 12119.

S22

VII. Drug Loading and Release in Mg2(olz)

100

40 Olsalazine Release (%) 20

0 0 2 4 6 8 10 Time (h)

Figure S27. Olsalazine release from Mg2(olz). Pellets were prepared from a circular die with a 4 mm diameter and pressed in a vise under a consistent pressure to produce 4.0 (± 0.3) mg pellets. The release experiments were carried out under simulated biological conditions where each pellet was placed in a 50 mL conical tube with 30 mL of phosphate- buffered saline (PBS). The tubes were oriented horizontally in the shaking incubator at 37 °C with bidimensional stirring at 60 rpm. Aliquots of 200 µL were removed at every time point, and 75 µL of each sample were transferred to a clear-bottom 96-well plate in duplicate and calibrated against Na2(olz) standards in PBS at known concentrations. Absorbance was measured at 360 nm by a Molecular Devices SpectraMax Paradigm plate reader.

S23

NH2

phenethylamine (TAAR1 agonist)

H N NH2 NH2 NH2 NH2

amphetamine β-methylphenylethylamine phentermine phenelzine (stimulant; treatment (TAAR1 agonist) (appetite suppresant) (antidepressant) for ADHD, narcolepsy)

OH OH HO NH NH 2 2 HO NH2 NH2

HO HO m-tyramine p-tyramine m-octopamine p-octopamine (dopaminergic agent) (dopaminergic agent) (adrenergic agent; (adrenergic agent; sympathomimetic drug) sympathomimetic drug)

HO NH2 HO NH2 HO NH2 HO NH2

HO HO HO O OH HO O OH dopamine norepinephrine levodopa methyldopa (neurotransmitter; (neurotransmitter; (dopamine prodrug used (alpha-adrenergic antagonist; hypotension treatment) hypotension treatment) in Parkinson's disease) hypertension treatment)

H N

N-methylphenethylamine (TAAR1 agonist) O OH OH NH H H H N N N O NH O methamphetamine ephedrine pseudoephedrine phenobarbital (stimulant) (bronchodilator) (nasal decongestant) (anti-seizure medication)

OH OH OH OH H H H H HO N HO N HO N N HO

HO HO HO phenylephrine epinephrine isoetarine salbutamol (vasoconstrictor; (used for anaphylaxis, cardiac (β2 -agonist; used for (β2 -agonist; used for decongestant) ""#$#%!"* bronchospasm and asthma) bronchospasm and COPD)

Figure S28. A selection of primary and secondary phenethylamine derivatives of pharmaceutical importance.

S24

OH O N OH NH HO N 2 O HO

olsalazine (H4olz) phenethylamine (PEA)

δ (ppm)

Figure S29. Digestion of Mg2(olz)(PEA)2 in DMSO-d6 (530 µL) and DCl 1 (20 µL). H NMR (600 MHz, DMSO-d6): olsalazine δ 8.26 (d, J = 2.5 Hz, 2H), 8.04 (dd, J = 8.9, 2.5 Hz, 2H), 7.15 (d, J = 8.9 Hz, 2H); phenethylamine 7.30 (t, J = 7.5 Hz, 4H), 7.22 (dd, J = 12.0, 7.3 Hz, 6H), 2.96 (d, J = 8.1 Hz, 4H), 2.91 – 2.85 (m, 4H).

S25

OH O H N OH N HO N O HO

olsalazine (H4olz) N-methylphenethylamine (Me-PEA)

δ (ppm)

Figure S30. Digestion of Mg2(olz)(Me-PEA)2 in DMSO-d6 (530 µL) and 1 DCl (70 µL). H NMR (400 MHz, DMSO-d6): olsalazine δ 8.15 (d, J = 2.5 Hz, 2H), 7.94 (dd, J = 8.9, 2.5 Hz, 2H), 7.06 (d, J = 8.9 Hz, 2H); N- methylphenethylamine δ 7.23 – 7.17 (m, 4H), 7.14 (dd, J = 7.6, 3.6 Hz, 6H), 2.98 (dd, J = 10.3, 5.9 Hz, 4H), 2.84 (dd, J = 10.3, 5.9 Hz, 4H), 2.44 (s, 6H).

S26

Figure S31. Infrared spectra of phenethylamine (blue), Mg2(olz)(PEA) 2 (black), and Mg2(olz) (red). It is apparent that the IR spectrum of Mg2(olz)(PEA)2 does not present a simple superposition of the Mg2(olz) and PEA IR spectra. The changes in the fingerprint region indicate interaction of the Mg2(olz) framework and adsorbed PEA in the solid state.

S27