Supporting Information

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1 A Calcium Coordination Framework Having Permanent Porosity and High CO 2 /N 2 Selectivity Debasis Banerjee, a, * Zhijuan Zhang, b Anna M. Plonka, c Jing Li, b, * and John B. Parise a, c, d, * (a) Department of Chemistry, Stony Brook University, Stony Brook, NY, (b) Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ (c) Department of Geosciences, Stony Brook University, Stony Brook, NY, (d) Photon Source Division, Brookhaven National Laboratory, Upton, NY Supporting Information 1

2 1. Synthesis Compound 1 was synthesized under solvothermal conditions using Teflon lined stainless steel Parr autoclaves. Starting materials include calcium chloride (CaCl 2, 96%, Acros-Organics), 4,4'-sulfonyldibenzoic acid (4,4'-SDB, 98%,Sigma-Aldrich) and ethanol (95%, Fisher-Scientific) and were used without purification. A mixture of moles of CaCl 2 (0.074g) and moles of 4,4'-SDB (0.198 g) were dissolved in10.05 gram of ethanol and stirred for 2 hours to achieve homogeneity [molar ratio of metal chloride: ligand: solvent =1:1:380]. The resultant solution was heated at 180 C for 5 days. Colorless needle shaped crystals were recovered as products and washed with and ethanol (Yield: 50% based on calcium in anhydrous CaCl 2, gram). The water comes from the 95% ethanol solvent and adsorbed moisture in the CaCl 2 reactant. The use of pure water as the synthesis solvent under identical synthesis conditions leads to formation of recrystallized organic linker as the main product. 2. Single Crystal and Powder X-ray Crystallography A suitable crystal of compound 1 was selected from the bulk sample and was mounted on a glass fiber using epoxy. Suitable single crystal of the activated compound 1' was collected from the activated bulk sample. Reflections for compounds 1 and 1' were collected using a four-circle Oxford Gemini diffractometer equipped with an Atlas detector (λ = Å) with 1 omega scans. The raw intensity data were collected, integrated and corrected for absorption effects using CrysAlis PRO software. 1 The crystal structures were solved using direct methods (SHELXS). 1 Calcium and sulfur atoms were located first followed by determination of other atom (O, C) positions from the Fourier difference map with all the non-hydrogen atoms being refined anisotropically. Hydrogen atoms were added in the structure using geometrical constraints (HFIX command). The crystallographic details can be found in Table S1. Bulk sample identification and phase purity were determined using powder x-ray diffraction. The data were collected using a Scintag Pad-X diffractometer equipped with Cu Kα (λ = Å) radiation within a range of 5 2θ 40 (step size: 0.02, counting time: 1s/step). Comparison of the observed and calculated powder x-ray diffraction patterns for compound [1] confirmed phase purity. 2

3 3. Thermal Analysis The Thermogravimetric (TG) data for compounds 1 were collected using a TGA Q500 instrument. The sample was heated from room temperature to 750 C under a N 2 atmosphere with a heating rate of 10 C/minute (Fig. S2). 4. Water Stability Study 10 ml of deionized water were added to ~100 mg of as-synthesized compound 1 or activated compound 1' kept in two separate vials. The materials were recovered after 5 days by filtration and the PXRD of the materials were collected (Figs. S7-8). 5. Gas Adsorption Experiments All gas sorption experiments were performed on a volumetric gas sorption analyzer (Autosorb-1- MP, Quantachrome Instruments). Liquid nitrogen and liquid argon were used as coolant to achieve cryogenic temperatures (77 and 87 K). Ultra high purity H 2, N 2 and CO 2 (99.999%) were used. The initial outgassing process for Ca(SDB) H 2 O (1) was carried out at 563 K under vacuum overnight. Outgassing samples in the amount of around mg were used for gas sorption measurements and the weight of 1 was recorded before and after outgassing to confirm the removal of guest molecules and to ensure the framework integrity. The outgassing procedure was repeated on the same sample between experiments for about 2-3 h. The hydrogen adsorption-desorption isotherms were collected in the pressure range from 10-4 to 1 atm at 87 and 77 K, respectively. Results for 1 are plotted in Fig. S9. Temperature-dependent adsorptiondesorption isotherms of CO 2 and N 2 (273, 288 and 298 K) on 1 were collected from 10-3 to 1 atm. The N 2 adsorption-desorption isotherms at 273, 288 and 298 K are depicted in Fig. S Dual Site Langmuir-Freundlich Model for CO 2 and N 2 Adsorption Isotherms The Dual site Langmuir-Freundlich (DSLF) model can be expressed as follows: N b p b p 1/ n1 1. n2 max 1 max 2 = N1 + N 1/ 2 n1 1/ n (1) 2 1+ b1 p 1+ b2 p 3

4 Here, p is the pressure of the bulk gas at equilibrium with the adsorbed phase (kpa), N is the adsorbed amount per mass of adsorbent (mol/kg), N 1 max and N 2 max are the saturation capacities of sites 1 and 2 (mol/kg), b 1 and b 2 are the affinity coefficients of sites 1 and 2 (1/kPa), and n 1 and n 2 represent the deviations from an ideal homogeneous surface. Here, the single-component CO 2 and N 2 adsorption isotherms have been fit to enable the application of IAST in simulating the performance of 1 under a mixed component gas. The fitting parameters of DSLF equation as well as the correlation coefficients (R 2 ) are listed in Table S3. The experimental and fitted isotherm for CO 2 and N 2 at 298 K are depicted in Fig. S11. Table S1: Crystallographic data and structural refinement details of compound 1 and 1' Compound 1 Compound 1' Empirical formula C 14 H 8 O 7 SCa C 14 H 8 O 6 SCa Formula weigh Collection Temperature(K) 298(2) 298(2) Wavelength(Å) Space Group P 21/n P 21/n a (Å) (3) (5) b (Å) (13) (2) c (Å) (6) (8) α ( ) β ( ) (2) (4) γ ( ) Volume(Å 3 ) (6) (10) Z 4 4 Calculated Density(g/cm 3 ) Absorption coefficient(mm -1 ) F(000) Crystal size (mm) 0.35 x 0.2 x x 0.15 x 0.10 Θ range of data collection Index range -15<=h<=15-14<=h<=14-7<=k<=7-30<=l<=30-6<=h<=6 Total reflection <=h<=28 Independent reflection 3675 [R(int) = ] 2998 [R(int) =

5 Goodness of fit Data/ Restraints/parameter 3675 / 0 / / 0 / 200 R1(on F 2 o, I>2σ(I)) wr2 (on F 2 o, I> 2 (I)) Table S2. Selected bond lengths (Å) and angles ( ) for compound 1. Ca(1)-O(1)# (11) O(4)#1-Ca(1)-O(3)# (4) Ca(1)-O(2)# (10) O(4)#1-Ca(1)-O(6) 90.38(4) Ca(1)-O(3)# (11) O(1)#4-Ca(1)-O(6) 87.67(4) Ca(1)-O(4)# (11) O(2)#3-Ca(1)-O(2)# (2) Ca(1)-O(6) (10) O(6)-Ca(1)-O(2)# (3) Symmetry code: #1 -x+1/2, y-1/2, -z+1/2. #2 -x+1/2, y+1/2, -z+1/2. #3 -x+1, -y+1, -z. #4 -x+1,- y+2, -z. #5 x+1/2, -y+3/2, z+1/2. Table S3. Equation parameters for the DSLF isotherm model. Adsorbates N 1 max (mmol/g) b 1 (kpa -1 ) n 1 N 2 max (mmol/g) b 2 (kpa -1 ) n 2 R 2 CO N

6 (a) (b) Fig.S1. (a) ORTEP view of compound 1, illustrating the numbering scheme. Ellipsoids are shown at 50% probability level. Hydrogen atoms are omitted for clarity. Symmetry related oxygen atoms are shown to complete the coordination sphere of the calcium center. (b) View of a single chain in ball-and-stick (left) and polyhedra (right) form. 6

7 Fig. S2. The TG plot of compound 1. The green line represents the weight loss profile and the blue line shows the associated derivatives of weight loss. Fig.S3. Polyhedral representation of the compound 1. M-O-M connectivity shows cornersharing chains. 7

8 Fig. S4. Polyhedral representation of the compound 1. M-O-M connectivity shows edge-sharing dimers. Fig.S5. The simulated (bottom), experimental (middle) and activated (top) PXRD patterns of compound 1. 8

9 Fig. S6. The PXRD patterns of the compound 1' (bottom: simulated pattern of compound 1, middle: after adsorption, top: after exposure to air for 2 days) Fig. S7. The TG-profile of compound 1' after gas-adsorption experiments 9

10 Fig. S8. TG-profile of compound 1' after exposure to air for 2 days Fig. S9. The PXRD pattern of water soaked (for 5 days) compound 1. 10

11 Fig. S10. The PXRD pattern of compound 1' after soaked in water for 5 days in comparison to compound 1' Fig. S11. H 2 adsorption-desorption isotherms at 77 K and 87 K. 11

12 Fig. S12. The N 2 adsorption-desorption isotherms at 273 K (black), 288K (red) and 298 K (blue). Fig. S13. Experimental and fitted isotherms for CO 2 and N 2 at 298 K. 12

13 Fig. S14. The IAST predicted isotherms of a binary mixture of CO 2 and N 2 (CO 2 :N 2 = 15:85) at 298 K as a function of the total pressure. References: 1. Sheldrick, G. M., Acta Crystallogr A 2008, 64, Oxford Diffraction (2010). CrysAlisPRO. Version 4. Oxford Diffraction Limited. Yarnton, Oxfordshire, England. 13