Supporting Information for manuscript entitled Chromatography in a Single. Northwestern University, Evanston, Illinois 60208, USA

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1 Supporting Information for manuscript entitled Chromatography in a Single Metal-Organic Framework Crystal by Shuangbing Han 1, Yanhu Wei 1,2, Cory Valente 2, István Lagzi 2, Jeremiah J. Gassensmith 2, Ali Coskun 2, J. Fraser Stoddart 2, Bartosz A. Grzybowski 1,2 * 1 Department of Chemical and Biological Engineering and 2 Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA Section 1. Preparation of MOF-5 single crystals. All reagents were purchased from Aldrich. Prior to use, DEF was distilled under reduced pressure. Borosilicate glass scintillation vials (20 ml) were purchased from VWR and rinsed with deionized water to remove any particulate matter, and dried in an 80 o C oven prior to use. Freshly distilled DEF (88 ml) was added to an Erlenmeyer flask containing Zn(NO 3 ) 2 6H 2 O (3.08 g) and benzene-1,4-dicarboxylic acid (578 mg). The mixture was stirred for 20 min. or until the solids dissolved. Portions (5 ml each) were removed by syringe and injected through a 13 mm syringe filter (0.45 μm PTFE membrane) into eighteen 20 ml scintillation vials, which were then sealed with a polypropylene-lined screw caps. The vials were placed in a large crystallizing dish and heated in an 85 C programmable oven for 72 h. The vials were removed and cooled to room temperature for 24 h, upon which the MOF-5 crystals were washed three times with fresh DMF. Most vials produced large cube-shaped crystals (between mm and mm) that were used for chromatography. MOF. The synthesis of MOF-5 was confirmed by unit cell measurements S1,S2 (see table S1). Importantly, unlike in other chromatographic MOF systems, activation and evacuation procedures were not necessary. S1

2 Section 2. Solvent effect on the stability of MOF-5 crystals. Figure S1. As synthesized mm-sized crystals were removed from solution of diethylformamide, placed on a glass microscope slide and imaged. Approximately 1-2 ml of test solvent was then placed onto the crystal. After 30 seconds, the crystals were imaged again. To ensure the damage to the crystals was not a result of solvent evaporation, the crystals were well irrigated. The scale bars in all images are 1 mm. Figure S2. Evaporation of low boiling solvent such as THF profoundly affects the integrity of the crystal. The scale bars in all images are 1 mm. Section 3. Determination of Crystallinity: S2

3 Single crystal X-ray structure determination of MOF-5: All measurements were made on a Bruker APEX-II CCD diffractometer with graphite monochromated Mo-Kα radiation. The data were collected at a temperature of 100(2) K with a theta range for data collection of 1.37 to 26.31º. Data were collected in 0.5º oscillations with 10 second exposures. The crystal-to-detector distance was mm. The structure was solved by direct methods and expanded using Fourier techniques3. The non-hydrogen atoms were refined anisotropically. Hydrogen atoms were included but not refined. Diffuse, disordered solvent molecules could not be adequately modeled. The bypass procedure in Platon (Spek, 1990) was used to remove the electronic contribution from these solvents. The total potential solvent accessible void volume was 12867Å 3 and the electron count / cell = As the exact solvent content is not known, the reported formula reflects only the atoms used in the refinement. Crystallinity determination of Dyes@MOF-5: To ensure that passive diffusion of dyes into the crystals did not affect the crystalline nature of the MOF-5 skeleton, we obtained unit cells for crystals used in molecule separation. A general procedure for unit cell determination is as follows: individual crystals were allowed to soak in DMF/dye solutions for 8-12 hours and the crystals were then subject to crystallographic analysis. Data for dyes@mof-5 were collected at 100 K using a Bruker APEX II CCD diffractometer (Cu-Kα and Mo-Kα radiation). Intensity data were collected using ω steps accumulating area detector frames spanning at least a hemisphere of reciprocal space for all structures. Data were integrated using SHELXTL. Diffraction patterns obtained from the samples were analyzed and the strong, symmetric rocking curves observed at high angle diffraction indicated that single crystallinity was maintained. While soaking dyes lowers the symmetry of MOF-5 from a face-centered cubic (F) to a primitive cubic (P) lattice, a comparison of unit cell parameters of single crystal samples before and after exposure to solvents and dyes confirmed that the dyes did not affect the integrity of MOF-5. The unit cells with parameters were listed as below: S3

4 TABLE S1: UNIT CELL PARAMETERS FOR MOF-5 AND a = b = c α = β = γ Crystal lattice type MOF (5) F Thionin@MOF (6) P Methylene bule@mof (5) P Pyronin B@MOF (5) P Azure A@MOF (6) P Section 4. Synthesis of organogel for dye mixture delivery (i) Synthesis of gel precursors modified from ref. 28 : furfurylamine (FA, 96 mmol) and bisphenol A diglycidyl ether (BADE, 48 mmol) were dissolved in DMF (160 ml), followed by heating at 90 C for two days. The reaction mixture was cooled down and stored in the dark. (ii) Preparation of FA-BADE organogel: 1,1 -(methylenedi-4,1-phenylene) bismaleimide (MBI, 6 mmol) was added to a solution of crude FA-BADE oligomer (containing about 12 mmol furfuryamido units) from step (i) followed by shaking for 10 min. and then leaving to stand at room temperature for 3 days to allow complete gelation to occur. (iii) Preparation of organogel stamps: A mixture of FA-BADE oligomers and MBI cross-linkers was cast against a clean silicon wafer. After gelation, the organogel layer was gently peeled off the wafer and then cut into small rectangular blocks ( stamps ), which were stored in closed vials until use. Section 5. Separation of dyes in single MOF-5 crystals Organogel blocks were soaked in DMF solutions of mixed organic dyes (2-10 mm each) for several hours. Prior to use, the soaked stamp was placed on a glass slide, and its surface was blotted dry first of all with tissue paper and then under a stream of S4

5 nitrogen. A cubic MOF-5 crystal with flat facets was placed onto the stamp. After a set time (t = 30, 90, 150 and 180 min.), the distribution of dyes within the crystal was analyzed either by stereomicroscopy or by fluorescence confocal microscopy on a Leica SP2 system with a Leica DMRXE7 upright microscope. Section 6. Chromatographic Parameters Typically, chromatographic parameters are calculated from the elution curve(s). Specifically, the number of theoretical plates, N, is expressed as N = 16(t r /w) 2, where t r stands for the retention time and w for the peak width (See Fig. S3a). The plate height (the height equivalent to a theoretical plate) is calculated as H = σ 2 /L, where σ stands for the standard deviation (σ = w/4, if the peak is a Gaussian distribution) and L is the distance traveled. The resolution of analytes A and B, R S, is calculated from R S = 2(t B -t A )/(w A +w B ) where t B and t A are the retention times of, respectively, A and B, and w A and w B are the corresponding peak widths (Fig. S3b). In our system, the number of theoretical plates (N), the resolution (R) and the plate height (H) can be estimated from the concentration profiles of the dyes (it should be pointed out, however, that these parameters are not directly comparable with the values reported for conventional chromatographic separations, where the sample is loaded at a certain time and the eluates emerging from the column are collected at different times; in our system, the sample is applied continuously and there are no well-defined elution times since the dyes stay within the crystal). Hence, in the analysis below, parameter t r with the units of distance is used in lieu of retention times. Figure S3. (a) A typical chromatographic elution curve and (b) elution curves for two separated peaks. S5

6 Figure S4. (a) Experimental concentration profiles measured by fluorescence confocal microscopy during separation of PB (red curve) and TH (green curve) in a MOF-5 crystal at 90 min separation time. The retention parameters τ PB and τ TH correspond to the distances the dyes migrate into the crystal (measured at peak maxima); w TH and w PB are the peak-width values for TH and PB obtained by drawing tangents to the sides of the profile curve at the inflection points and extrapolating the tangents to intercept the baseline the distance between the intercepts is then the peak width. R S is the resolution between two peaks. (b) The calculated resolution, R S values, the number of theoretical plates, N, and the plate height, H, at different separation times based on the intensity profiles of mixed PB and TH inside of MOF-5 crystals (N and H were calculated based on the distance PB migrates into the crystal). References S1. Li, H.; Eddaoudi, M.; O Keeffe, M.; Yaghi, O. M. Nature 1999, 402, S2. Eddaoudi, M.; Kim, J.; Rosi, N.; Vodak, D.; Wachter, J.; Ookeeffe, M.; Yaghi, O. M. Science 2002, 295, S6