Supporting Information

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1 Supporting Information Tailoring the Pore Environment of a Robust Ga-MOF by Deformed [Ga 3 O(COO) 6 ] Cluster for Boosting C 2 H 2 Uptake and Separation Yun-Tong Li, Jian-Wei Zhang,*,, Hong-Juan Lv, Man-Cheng Hu, Shu-Ni Li, Yu-Cheng Jiang and Quan-Guo Zhai*, Key Laboratory of Macromolecular Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi an, Shaanxi, , China Henan Engineering Center of New Energy Battery Materials, Henan D&A Engineering Center of Advanced Battery Materials, School of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu, Henan, , China *Corresponding Authors: * zhaiqg@snnu.edu.cn (Q. G. Zhai). * jwzhang85@163.com (J. W. Zhang). S1

2 EXPERIMENTAL SECTION Materials and Methods. All chemicals were obtained from commercial sources and used without further purification. Powder X-ray diffraction (PXRD) data were collected on a Rigaku MiniFlex600 (40 kv, 15 ma) diffractometer Cu Kα (λ = Å) at room temperature. The simulated PXRD pattern was calculated using the single-crystal X-ray diffraction data and generated by using Mercury program (version 3.6). Thermogravimetric analyses (TGA) were performed on a NETZSCH STA 449C thermal analyzer at a heating rate of 2 C min -1 under N 2 atmosphere. Scanning Electron Microscope (SEM) images was taken on a Philips-FEI Quanta 200. X-ray Crystallography. Single-crystal X-ray diffraction data of SNNU-63 was collected on Bruker D8 PHOTO 100 CMOS diffractometer equipped with a graphite-monochromated Mo Kα radiation (λ = Å) at 153 K. The SADABS program was used for absorption correction. The structure was solved by Patterson method and refined with full-matrix least-squares on F 2 technique in the SHELXTL crystallographic software package. 1 All non-hydrogen atoms in the framework were refined with anisotropic displacement parameters. The residual Q peaks probably correspond to highly disordered solvent molecules were treated using the SQUEEZE routine in the PLATON software package. 2 Crystallographic details and selected bond lengths are summarized in Tables S1 and S2. This crystal data can be obtained free of charge from the Cambridge Crystallographic Data Centre (CCDC) through Gas Adsorption Measurements. Gas adsorption isotherms were measured on a Micromeritics ASAP 2020 HD88 surface-area and pore-size analyzer up to 1 bar of gas pressure by the static volumetric method. All used gases were of 99.99% purity. The N 2 gas sorption isotherm was measured at 77 K with liquid nitrogen, and the gas sorption isotherms for CO 2, CH 4, C 2 H 2 and C 2 H 4 were collected at three different temperatures of 273 K, 283 K and 298 K, respectively. Prior to gas adsorption-desorption measurement, the as-synthesized samples were activated by immersion in CH 2 Cl 2 for 4 days, and the exchanged samples were outgassed under dynamic vacuum at room temperature for 2 h and then at 120 C for 12 h until a degassing rate of 2 μm Hg min 1 was reached. Dynamic Gas Breakthrough Experiments. The breakthrough experiments were carried out on a self-built dynamic gas breakthrough equipment. A stainless steel column with a length of 120 mm and an internal diameter of 4 mm was used for packing the activated crystalline SNNU-63 samples (0.77 g). The mixed gas flow and pressure were controlled by using a pressure controller valve and a mass flow controller. Then the column packed with samples were first flushed with helium gas at the rate of 50 ml/min for 1 h at room temperature. The outlet effluent from the column was continuously monitored using gas analytical mass spectrometer (Hiden, HPR-20 R&D). Helium gas was introduced into the column to further purge the adsorbent, and the pressure of sweeping was often 2-3 bar. The flow of He was then turned off, while a S2

3 gas mixture was allowed to flow into the column. The outlet composition was continuously monitored by gas chromatograph until complete breakthrough was achieved. The result of the breakthrough experiment was collected by the gas mass spectrometry detection system. Grand Canonical Monte Carlo (GCMC) simulations. GCMC simulations were performed with the sorption module of Materials Studio 8.0 package. The supercell of SNNU-63 was used as the simulation system. A total of steps was used for equilibration, and production steps were used to calculate the ensemble average of gas adsorption sites. During the simulation, we used the standard universal force field (UFF) to describe the gas-framework interaction and the gas-gas interaction, and used the Forcite module to calculate the energy for the system (the frameworks and gas molecules). The cut-off radius used for the Lennard Jones interactions was 18.5 Å. The simulated gas density distributions were simulated by setting parameters in the sorption model at 298 K and 1.0 atm. S3

4 Table S1. Crystal data and structure refinements for SNNU-63. Compound SNNU-63 Formula C 32 H 17 Ga 3 O 16 Formula weight Temperature (K) 153(2) Crystal system orthorhombic Space group Pmn2 1 a(å) (17) b(å) (7) c(å) (13) α (deg) β (deg) γ (deg) Volume(Å 3 ) (5) Z 2 d calcd. (g cm -3 ) μ(mm -1 ) F(000) 860 Reflections collected/unique 70975/7613 R int Data/restraints/parameters 7613/13/238 GOF on F R 1a, wr b 2 [I > 2σ(I)] , R 1a, wr b 2 (all data) , a R 1 = Σ F o - F c /Σ F o. b wr 2 = [Σw(F 2 o - F c2 ) 2 /Σw(F o2 ) 2 ] 1/2. Table S2. Selected bond lengths (Å) for SNNU-63. Ga(1)-O(1) 1.958(4) Ga(2)-O(2) 1.969(3) Ga(1)-O(3) 1.936(3) Ga(2)-O(2)#a 1.969(3) Ga(1)-O(5) 1.966(5) Ga(2)-O(4) 2.001(3) Ga(1)-O(7) 2.059(3) Ga(2)-O(4)#a 2.001(3) Ga(1)-O(8) 2.109(3) Ga(2)-O(6) 1.996(5) Ga(1)-O(9) 1.852(2) Ga(2)-O(9) 1.906(4) Symmetry codes: #a: -x, y, z. S4

5 Figure S1. Scanning electron microscope photographs of SNNU-63. (a) (b) Figure S2. (a) The asymmetric unit of SNNU-63. (b) The description of linkage between each angular PTC ligand and deformed [Ga 3 O] clusters. (symmetry code: a = -x, y, z.) Figure S3. Comparison of the C- 3 -O-C angles in the [Ga 3 (μ 3 -O)] trimer present in SNNU-63 (a) and SNNU-65s (b). S5

6 Figure S4. Comparison of the dihedral angles between the two biphenyl rings derived from PTC in the crystal structure of SNNU-63 and SNNU-65s. S6

7 Topological Analysis for SNNU-63. Prior to topological analysis, the structure has been simplified to its points of extension (carboxylate C atoms of the linker), the trigonal PTC ligand can be simplified as a 3-connected node having triangle geometry, and while µ 3 -O trimer cluster are then reduced to a 6-connected node (deformed trigonal-prismatic geometry), respectively. SNNU-63 exhibits an edge transitive (3,6)-connected sit topolopy: Point symbol for net: {4.6 2 } 2 { } TD10 = 1183 Topological terms for each node: (V1 for PTC 3- ligand) Point symbol: {4.6 2 } Extended point symbol: [4.6(2).6(2)] Coordination sequence: (V2 for µ 3 -O trimer cluster) Point symbol: { } Extended point symbol: [ (2).6(2).8(5).8(5).8(8)] Coordination sequence: Transitivity: [2232] Tilling: [ ] + [ ] Topological type: sit S7

8 Figure S5. TGA curves of as-synthesized (black) and solvent-exchanged samples (red) for SNNU-63. Figure S6. PXRD patterns of as-synthesized samples and after gas adsorption for SNNU-63. S8

9 Selectivity Prediction for Binary Mixture Adsorption. Ideal adsorbed solution theory (IAST) was used to predict binary mixture adsorption from the experimental pure-gas isotherms. To perform the integrations required by IAST, the single-component isotherms should be fitted by a proper model. The Dual-Site Langmuir Freundlich (DSLF) equation was found to the best fit to the experimental pure isotherms for CO 2, C 2 H 2, and C 2 H 4 and CH 4 of SNNU-63. On the base of the equation parameters of pure gas adsorption, the IAST model was further used to investigate the separation of CO 2 /CH 4, C 2 H 2 /CH 4, C 2 H 4 /CH 4, and C 2 H 2 /CO 2. q b p 1/ n1 1 qm 1 + 1/ n1 1 b1 p q m2 b2 p 1 b p 2 1/ n 2 1/ n 2 where p is the pressure of the bulk gas at equilibrium with the adsorbed phase (kpa), q is the adsorbed amount per mass of adsorbent (mmol g -1 ), q m1 and q m2 are the saturation capacities of site 1 and 2 (mmol g -1 ), b 1 and b 2 are the affinity coefficients of site (1/kPa), and n 1 and n 2 represent the deviations from an ideal homogeneous surface. The correlation coefficients (R 2 ) values for all of the fitted isotherms were over Hence, the fitted isotherm parameters were applied to perform the necessary integrations in IAST. Based on the above equation parameters of pure gas adsorption, we used the IAST model to investigate the separation of CO 2 /CH 4, C 2 H 2 /CH 4, C 2 H 4 /CH 4 and C 2 H 2 /CO 2. The adsorption selectivity is defined by: xa / ya sa/ B xb / yb Where x i and y i are the mole fractions of component i (i = A, B) in the adsorbed and bulk phases, respectively. Note that in the Henry regime S A/B is identical to the ratio of the Henry constants of the two species. S9

10 Figure S7. Comparison of experimental isotherms and simulated isotherms (Left Y axis), and mixture adsorption selectivity predicted for the three different composition selectivity predicted by IAST (Right Y axis) of SNNU-63 for binary mixture at 273 K. S10

11 Figure S8. Comparison of experimental isotherms and simulated isotherms (Left Y axis), and mixture adsorption selectivity predicted for the three different composition selectivity predicted by IAST (Right Y axis) of SNNU-63 for binary mixture at 298 K. S11

12 Figure S9. Experimental column breakthrough curves of SNNU-63 for equimolar C 2 H 4 /CH 4 and CO 2 /CH 4 mixtures at 273 K and 1 atm, respectively. Figure S10. Experimental column breakthrough curves of SNNU-63 for equimolar C 2 H 2 /CH 4, C 2 H 4 /CH 4, CO 2 /CH 4 and C 2 H 2 /CO 2 mixtures at 298 K and 1 atm, respectively. S12

13 Figure S11. Simulated favorable the C 2 H 4 density distribution in SNNU-63 skeleton at 298 K and 1 atm. REFERENCES (1) (a) Sheldrick, G. M. SHELXS 97: Program for the Solution of Crystal Structure; University of Göttingen: Göttingen, Germany, (b) Sheldrick, G. M. SHELXS 97: Program for the Crystal Structure Refinement; University of Göttingen: Göttingen, Germany, (c) Sheldrick, G. M. SADABS: Siemens Area correction Absorption Program; University of Göttingen: Göttingen, Germany, (2) Spek, A. L. Single-crystal structure validation with the program PLATON. J. Appl. Crystallogr. 2003, 36, S13