Supporting Information

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1 Supporting Information A Triazole-Containing Metal-rganic Framework as a Highly Effective and Substrate Size-Dependent Catalyst for C 2 Conversion Pei-Zhou Li,,, Xiao-Jun Wang,,, Jia Liu,,, Jie Sheng Lim, Ruqiang Zou,*,, and Yanli Zhao*,,,# Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, anyang Technological University, 21 anyang Link, Singapore Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing , China Singapore Peking University Research Centre for a Sustainable Low-Carbon Future, 1 Create Way, Singapore # School of Materials Science and Engineering, anyang Technological University, 50 anyang Avenue, , Singapore These authors contributed equally to this work. *Corresponding Authors. rzou@pku.edu.cn; zhaoyanli@ntu.edu.sg S1

2 General information All starting materials are commercially available and were used as received unless specifically mentioned: bis(triphenylphosphine)palladium(ii) dichloride (Pd(PPh 3 ) 2 Cl 2, 98%, Sigma-Aldrich), copper(i) bromide (CuBr, 98%, Sigma-Aldrich), copper(ii) nitrate hemi(pentahydrate) (Cu( 3 ) 2 2.5H 2, 98%, Alfa Aesar), copper(ii) sulphate pentahydrate (CuS 4 5H 2, 99%, Alfa Aesar), diisopropyl amine (DIPA, 99.5%, Sigma-Aldrich),, -dimehtylformamide (DMF, 99.8%, Sigma-Aldrich), dimethyl 5-aminoisophthalate (98%, Sigma-Aldrich), hydrochloric acid (HCl, 37w%, MSR), sodium L-ascorbate ( 98%, Sigma-Aldrich), sodium azide (a 3, 99.5%, Sigma-Aldrich), sodium nitrite (a 2, 97%, Sigma-Aldrich), tetrakis(4-bromophenyl)methane ( 95%, TCI), triphenylphosphine (Ph 3 P, 98.5%, Sigma-Aldrich), and (trimethylsilyl)acetylene (TMSA, 98%, Alfa Aesar). 1 H MR measurements were conducted on either a JEL ECA400 MR spectrometer or a JEL ECA400 SL MR spectrometer at ambient temperature. All 1 H MR spectra were reported as chemical shift δ in units of parts per million (ppm) downfield with reference to deuteratred solvent (2.50 ppm for DMS-d 6 and 7.26 ppm for CDCl 3 ) or TMS (0.00 ppm). Multiplicities were presented as: s (singlet); d (doublet); t (triplet); and m (multiplet). Coupling constants J values were expressed in Hz and the number of protons was expressed as nh. 13 C MR spectra were obtained from a JEL ECA400 MR spectrometer at ambient temperature. Spectra were reported as chemical shift δ in units of parts per million (ppm) downfield with reference to deuteratred solvent (39.81 ppm for DMS-d 6 or ppm for CDCl 3 -d 1 ). High resolution mass spectra (HRMS) or mass spectra (MS) were carried out on a Waters Q-tof Premier mass spectrometry. Melting point experiments were carried out on a SRS ptimelt automated melting point system. Single crystal X-ray diffraction measurements were performed on a Superova X-ray diffraction system from Agilent Technologies. Powder X-ray diffraction (PXRD) data were collected at 40 kev, 15 ma on a Rigaku MiniFlex 600 Benchtop diffractometer using Cu-Kα radiation (λ = Å) over 2θ range of at room temperature. Thermogravimetric analyses (TGA) were carried out on a TGA-Q500 thermoanalyzer with a heating rate of 10 C min -1 under 2 flow (60 ml/min) from room temperature to 700 C. Gas sorption analyses were conducted using Quantachrome Instruments Autosorb-iQ (Boynton Beach, Florida USA) with extra-high pure gases. S2

3 Experimental section 4 CuS + 4 Sodium L-ascorbate 3 Me 8 L1 ah/h 2 HCl H H H H 1 3 K 2 C 3 Si Br TMSA, DIPA, PPh 3 Br Br Si Si Pd(PPh 3 ) 2 Cl 2, CuI Br Si Scheme S1. Synthetic route for the preparation of ligand H 8 L1. 2 H H H 8 L1 H H Dimethyl 5-azidoisophthalate (1). Compound 1 was synthesized according to the reported method with slight modifications. S1,S2 Dimethyl 5-aminoisophthalate (3.72 g, 17.8 mmol) was added into a mixture of MeH (200 ml) and HCl (0.5 M, 200 ml) at 0 C. Subsequently, a water solution of a 2 (3.68 g, 53.3 mmol, 20 ml H 2 ) was slowly added into the above solution, and the resulted mixture solution was stirred at 0 C for 1.5 h. Then, a solution of a 3 (3.50 g, 53.8 mmol, 20 ml H 2 ) was slowly poured into the above mixture solution at 0 C with stirring for 30 min, followed by extraction with CH 2 Cl 2 (100 ml 2). The combined organic layer was dried over a 2 S 4 and the solvent was evaporated under vacuum. The crude product was purified by silica gel flash column chromatography (hexane/ch 2 Cl 2, 100/70) to give compound 1 as a white solid (3.81 g, 16.2 mmol, yield 91%, melting point: o C). 1 H MR (400 MHz, CDCl 3 ): 8.43 (t, J = 1.5 Hz, 1H), 7.87 (d, J = 1.5 Hz, 2H), 3.95 (s, 6H). 13 C MR (400 MHz, CDCl 3 ): , , , , , FTIR (KBr) υ/cm -1 : (w), (w), (w), (s), (s), (s), (m), (m), (m), (m), (s), (m), 968.3(w), 760.0(m), 721.4(w), 702.1(w). ESI-TF-HRMS: m/z calcd for C 10 H : , found: [M+H] +. Tetrakis(4((trimethylsilyl)ethynyl)phenyl)methane (2). Compound 2 was synthesized according to literature reported method with slight modifications. S3,S4 Diisopropyl amine (15 ml) and S3

4 trimethylsilyl acetylene (3.4 ml, 2.36 g, 2.40 mmol) were injected into a dried THF solution (50 ml) containing tetrakis(4-bromophenyl)methane (1.50 g, 2.36 mmol) and triphenylphosphine (62.4 mg, 0.24 mmol) under 2 environment. Subsequently, bis(triphenylphosphine)palladium(ii) dichloride (83.5 mg, 0.12 mmol) and copper(i) bromide (22.7 mg, 0.16 mmol) were added into the mixture solution under 2 environment, and it was subjected to high temperature at 60 C and reflux for 20 hours. After cooling down to room temperature naturally, the insoluble substance was filtered out followed by CH 2 Cl 2 washing. The filtrate was then washed by water and then extracted with CH 2 Cl 2 (100 ml 2). The combined organic layer was dried over a 2 S 4 and the solvent was evaporated under vacuum. The crude product was purified by flash column chromatography on silica gel using hexane as eluent to give compound 2 as a white solid (1.28 g, 1.81 mmol, yield: 77%, melting point: o C). 1 H MR (400 MHz, CDCl 3 ): 7.32 (d, J = 8.5 Hz, 8H), 7.03 (d, J = 8.5 Hz, 8H), 0.23 (s, 36H). 13 C MR (400MHz, CDCl 3 ): , , , , , 94.84, 64.82, FTIR (KBr) υ/cm -1 : (m), (m), (w), (w), (s) (s), (w), (s), (m), (m), 866.0(s), 842.9(s), 810.1(s), 760.0(s), 700.2(w), 653.9(m), 640.4(m), 597.9(w). ESI-TF-HRMS: m/z calculated for Mr of C 45 H 53 Si 4 : , found: [M + H] +. Tetrakis(4-ethynylphenyl)methane (3). Potassium carbonate (K 2 C 3, 1.38 g, mmol) was added into a DCM/MeH (30 ml/30 ml) solution of 2 (1.2 g, 1.70 mmol), and then the mixture was stirred at room temperature overnight. The mixture solution was poured into water (50 ml) and then extracted by CH 2 Cl 2 (50 ml 2). The combined organic layer was dried over a 2 S 4 and the solvent was evaporated under vacuum. The crude product was purified by silica gel flash column chromatography (hexane/ch 2 Cl 2, 100/10) to give 3 as a white solid (0.64 g, 1.54 mmol, yield: 90%, melting point: o C). 1 H MR (400MHz, CDCl 3 ): 7.38 (d, J = 8.2 Hz, 8H), 7.11 (d, J = 8.2 Hz, 8H), 3.06 (s, 4H). 13 C MR (400Hz, CDCl 3 ): , , , , 83.25, 77.70, FTIR (KBr) υ/cm -1 : (s), (w), (w), (w), (w), (w), (w), (w), (s), (m), (m), (m), 825.5(s), 667.4(m), 640.4(m), 569.0(m), 559.4(m). ESI-TF-HRMS: m/z calculated for Mr of C 33 H 21 : , found: [M + H] +. S4

5 ctamethyl 5,5',5'',5'''-((methanetetrayltetrakis(benzene-4,1-diyl)) tetrakis (1H- 1,2,3-triazole-4,1-diyl))tetraisophthalate (Me 8 L1). Me 8 L1 was synthesized in accordance to literature reported method with slight modifications. S1,S2 Above synthesized 1 (1.13 g, 4.80 mmol) and 3 (0.42 g, 1.00 mmol) were added into a mixture of THF/H 2 (150 ml/30 ml). Then, CuS 4 5H 2 (0.11 g, 0.44 mmol, 10 ml H 2 ) and excess sodium L-ascorbate (0.5 g, 2.5 mmol, 10 ml H 2 ) were added into the solution, and the mixture solution was stirred at 50 C under 2 for 3 days. The mixture solution was poured into water (50 ml) and then extracted by CH 2 Cl 2 (80 ml 2). The combined organic layer was dried over a 2 S 4 and the solvent was evaporated under vacuum. The crude product was purified by silica gel flash column chromatography (CH 2 Cl 2 /EtAc, 100/20) to give compound Me 8 L1 as a light yellow solid (1.21 g, 0.89 mmol, yield: 89%, became black before melting at above 260 o C). 1 H MR (400MHz, DMS-d 6 ): 9.50 (s, 4H), 8.61 (d, J = 1.4 Hz, 8H), 8.41 (t, J = 2.8 Hz, 4H), 7.92 (d, J = 8.5 Hz, 8H), 7.42 (d, J = 8.5 Hz, 8H), 3.94 (s, 24H). 13 C MR (400Hz, DMS-d 6 ): , , , , , , , , , , , , FTIR (KBr) υ/cm -1 : (s), (w), (s), (m), (m), (m), (m), (m), (s), (w), (m), (m), 958.6(w), 829.4(w), 758.0(m), 721.4(w). ESI-TF-MS: m/z calculated for Mr of C 73 H : , found: [M + H] +. 5,5',5'',5'''-((Methanetetrayltetrakis(benzene-4,1-diyl)) tetrakis (1H-1,2,3-triazole-4,1-diyl))tetraisophthalic acid (H 8 L1). Compound Me 8 L1 (1.10 g, 0.81 mmol) was hydrolyzed with excess ah (0.16 g, 4.0 mmol) in a solution of THF/H 2 (60 ml/30 ml). The mixture was stirred at room temperature overnight. THF in the reaction mixture was then removed under reduced pressure to yield an aqueous solution. Then, the resulting solution was acidified with HCl in high concentration to ph = 1. The solid was collected by centrifugation, rinsed several times with distilled water, and dried to afford white solid H 8 L1 (0.95 g, 0.76 mmol, yield: 94%, became black before melting at above 260 o C). 1 H MR (400MHz, DMS-d 6 ): (s, 8H), 9.60 (s, 4H), 8.70 (d, J = 1.4 Hz, 8H), 8.52 (t, J = 2.9 Hz, 4H), 7.98 (d, J = 8.5 Hz, 8H), 7.46 (d, J = 8.5 Hz, 8H). 13 C MR (400MHz, DMS-d 6 ): , , , , , , , , , , , FTIR (KBr) υ/cm -1 : (s), (s), (w), (s), (s), (m), (m), (s), (w), (m), S5

6 1018.4(m), 977.9(w), 906.5(w), 829.4(m), 761.9(s), 707.9(w), 669.3(m). ESI-TF-MS: m/z calculated for Mr of C 65 H : , found: [M + H] +. MF 1. Compound H 8 L1 (15 mg, mmol) and Cu( 3 ) 2 2.5H 2 (24 mg, 0.10 mmol) were dissolved in a solution consisting of, -dimethylformamide (DMF, 10 ml), ethanol (1 ml) and H 2 (1 ml). Then, the mixture solution was placed in a tightly capped 20 ml vial after adding drops of acid, which was heated in an oven at 80 C for 3 days. The blue block crystals were collected after cooling the sample down to room temperature. The crystals were washed by fresh DMF for three times and dried naturally at room temperature to yield 1 (Yield: 21.5 mg weighted after drying by 2 ). X-ray crystallography. The single crystal of 1 suitable for X-ray analysis was picked up under a microscope from freshly synthesized solution and then mounted immediately. The diffraction data were collected at 293 K using graphite-monochromated Cu-Kα radiation (λ = A) on a Superova X-ray Diffraction System from Agilent Technologies. The program SAIT was used for integration of the diffraction profiles, S5 and the data were corrected for absorption by using the SADABS program. S6 The structures were solved by the direct methods using the SHELXS program of the SHELXTL package and refined by full-matrix least-squares analyses on F 2 (SHELXTL-97). S7 Metal atoms in each complex were located from the E-maps, and other non-hydrogen atoms were located in successive difference Fourier syntheses. The hydrogen atoms of the ligand were generated theoretically onto the specific atoms and refined isotropically with fixed thermal factors. The isolated solvent molecules in the MF are highly disordered and cannot be modeled, thus the SQUEEZE routine of PLAT was applied to remove the contributions of the solvent molecules to the scattering. S8 Further details of crystallographic data and structural analysis are summarized in Table S1. CCDC contains the supplementary crystallographic data for 1. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via S6

7 Gas sorption. Low-pressure gas sorption measurements were performed by using Quantachrome Instruments Autosorb-iQ (Boynton Beach, Florida USA) with the extra-high pure gases. The as-synthesized crystals of MF 1 were immersed in CH 3 Cl (20 ml) for 3 days, during which time CH 3 Cl was replaced three times. Then, the samples were moved into a sample cell and dried under vacuum at 80 C by using the outgasser function for 6 h before the measurements. The Brunauer Emmett Teller (BET) surface area and total pore volume were calculated from the 2 sorption isotherms at 77 K, and the pore size distribution was calculated based on the 2 sorption isotherm by using on-local Density Functional Theory (L-DFT, a carbon model containing slit/cylindrical pore) model in the Quantachrome ASiQwin 2.01 software package. The isosteric heat of adsorption (Q st ) for C 2, defined as Q st 2 ln p RT T q (Clausius-Clapeyron equation) was determined by using the C 2 adsorption isotherms at 273 and 298 K (ASiQwin 2.01). Catalysis experiments. In a typical reaction, the catalytic reaction was conducted in a Schlenk tube using epoxide (20 mmol) with C 2 purged at 1 atm under solvent free environment at room temperature, catalyzed by 0.2 mol% per copper paddlewheel unit of MFs (15.6 mg for 1, or 8.8 mg for HKUST-1) with a co-catalyst of tetra-n-tertbutylammonium bromide (TBAB, 0.65 g, 10 mol%) for 48 hours. The yields were calculated based on 1 H MR analysis. The recovered catalyst was collected by centrifuge, washed by fresh CH 3 Cl and dried by vacuum. S7

8 Table S1. Crystallographic data and structure refinement summary for MF 1. 1 Formula C 65 H Cu 4 Mr Temperature (K) 293(3) Wavelength Crystal system Space group Å rthorhombic C222 a,b,c / Å a = (6) Å, b = (3) Å, c = (3) Å V, Å (4) Z 4 Dcalc (g cm -3 ) Crystal size (mm) Theta range (deg) 3.57 to Reflections unique/collected 11399/18622 R int Goodness-of-fit on F S8

9 Figure S1. Photographs of as-synthesized crystals of 1. (a) (b) (c) H H H H H H H H (d) (e) Figure S2. (a) Chemical structure of the clicked ligand H 8 L1, (b) L1 connected eight paddlewheel Cu 2 units, (c) isophthalate moieties from L1 connected Cu 2 clusters giving the formation of 2D lamellar with regularly arranged open metal-sites, (d) 3D framework of 1 showing high framework porosity, and (e) (4,3,4)-network of 1. S9

10 Weight (%) Activated As-synthesized Calculated theta(degree) Figure S3. PXRD patterns of 1, indicating that the framework was retained after the activation process Temperature ( o C) Figure S4. TGA plot of as-synthesized 1, indicating that the framework was stable up to ~250 o C. The initial sharp weight loss can be attributed to the weight loss of solvents (water and DMF) in the pore of framework. S10

11 Q st (kj/mol) 1/[W((P o /P) -1)] Surface Area = m 2 /g BET summary Slope = Intercept = 9.293e-04 Correlation coefficient, r = C constant = Figure S5. BET specific surface area plot of activated 1. Relative Pressure P/P 0 V (C 2 / 2 ) at STP / cm 3 g C 2, 273K C 2, 298K 2, 273K 2, 298K Relative Pressure P/P Volume (cc/g) Figure S6. (Left) C 2 and 2 adsorption isotherms of activated 1 at 273 K and 298 K respectively, and (Right) its isosteric heat of C 2 adsorption calculated from the adsorption isotherms at 273 K and 298 K. S11

12 250 V (H2) at STP / cm 3 g Relative Pressure P/P 0 Figure S7. H 2 adsorption isotherms of activated 1 at 77 K, showing H 2 adsorption capabilities of at 1 atm and 77K. V (CH 4 ) at STP / cm 3 g CH 4, 273K CH 4, 298K Relative Pressure P/P 0 Figure S8. CH 4 adsorption isotherms of activated 1 at 273 and 298 K, showing CH 4 adsorption capabilities of 66.1 and 35.1 cm 3 g -1 at 273 and 298 K under 1atm, respectively. S12

13 Yield(%) % 96% 96% 95% 95% 80 Y Cycles Figure S9. Recyclability characterization of 1 in five runs for catalytic C 2 cycloaddition with propylene oxide to produce propylene carbonate. Recollected Calculated theta(degree) Figure S10. PXRD patterns of 1 recollected after catalysis reactions and calculated from the crystal data, indicating that the framework was retained after the catalysis reactions. S13

14 Figure S11. Scheme of possible catalytic mechanism for the reaction of epoxide and C 2 into cyclic carbonate catalyzed by MF 1 (peacock blue sphere: open Cu site; L + = tetra-n-butylammonium). The MF presents a high activity on C 2 conversion due to its exposed Lewis-acid Cu sites. As shown in the scheme, the unsaturated orbital of copper in the activated MF 1 can accept the electrons from donators such as the atom of propylene oxide. After binding with copper, part of electron transfer from the atom of epoxide to copper results in the weakness of C- bond of epoxide. Subsequently, the Br - generated from nbu 4 Br attacks the less-hindered carbon atom of epoxide to open the epoxy ring due to its higher positive charge and lower steric effect. Then, the oxygen atom from C 2 attacks the positively charged carbon of epoxide cooperated with attacking from the atom of epoxide to the C atom of C 2, followed by a ring closure step to give the production of cyclic carbonate. S14

15 Table S2. Yields of various cyclic carbonates prepared from the cycloaddition of C 2 with small/big-size epoxides catalyzed by 1. Entry Epoxides Products Yields Small substrates Cl 4 88 Br Large substrates Cl Br Characterization spectra 1 H MR spectrum of dimethyl 5-azidoisophthalate in CDCl 3. S15

16 13 C MR spectrum of dimethyl 5-azidoisophthalate in CDCl 3. HRMS spectrum of dimethyl 5-azidoisophthalate S16

17 FT-IR spectrum of dimethyl 5-azidoisophthalate 1 H MR spectrum of tetrakis(4((trimethylsilyl)ethynyl)phenyl)methane in CDCl 3. S17

18 13 C MR spectrum of tetrakis(4((trimethylsilyl)ethynyl)phenyl)methane in CDCl 3. HRMS spectrum of tetrakis(4((trimethylsilyl)ethynyl)phenyl)methane S18

19 FT-IR spectrum of tetrakis(4((trimethylsilyl)ethynyl)phenyl)methane 1 H MR spectrum of tetrakis(4-ethynylphenyl)methane in CDCl 3 (trace DCM was observed). S19

20 13 C MR spectrum of tetrakis(4-ethynylphenyl)methane in CDCl 3 HRMS spectrum of tetrakis(4-ethynylphenyl)methane S20

21 FT-IR spectrum of tetrakis(4-ethynylphenyl)methane 1 H MR spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalate in DMS-d 6. S21

22 13 C MR spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalate in DMS-d 6. MS spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalate. S22

23 FT-IR spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalate. 1 H MR spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalic acid in DMS-d 6. S23

24 13 C MR spectrum of 5,5',5'',5'''- ((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1h-1,2,3-triazole-4,1-diyl))tetraisophthalic acid in DMS-d 6. MS spectrum of 5,5',5'',5'''-((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1H-1,2,3-triazole-4,1-diyl)) tetraisophthalic acid. S24

25 FT-IR spectrum of 5,5',5'',5'''-((methanetetrayltetrakis(benzene-4,1-diyl))tetrakis(1H-1,2,3-triazole-4,1-diyl)) tetraisophthalic acid. References S1. Wang, X.-J.; Li, P.-Z.; Chen, Y.; Zhang, Q.; Zhang, H.; Chan, X. X.; Ganguly, R.; Li, Y.; Jiang, J.; Zhao, Y. Sci. Rep. 2013, 3, S2. Li, P.-Z.; Wang, X.-J.; Tan, S.Y.; Ang, C.Y.; Chen, H.-Z. Liu, J.; Zou, R.-Q.; Zhao, Y. Angew. Chem. Int. Ed. 2015, 54, S3. Plietzsch,.; Schilling, C. I.; Tolev, M.; ieger, M.; Richert, C.; Muller, T.; Brase, S. rg. Biomol. Chem. 2009, 7, S4. Pandey, P.; Farha,. K.; Spokoyny, A. M.; Mirkin, C. A.; Kanatzidis, M. G.; Hupp, J. T.; guyen, S. T. J. Mater. Chem. 2011, 21, S5. SAIT V6.1, Bruker Analytical X-ray Systems, Madison, WI, S6. Sheldrick, G. M. SADABS, Empirical Absorption Correction Program, University of Göttingen, Göttingen, Germany, S7. Sheldrick, G. M. Acta Crystallogr. Sect. A: Found. Crystallogr. 2008, 64, 112. S8. Spek, A. L. J. Appl. Crystallogr. 2003, 36, 7. S25