Supramolecular imidazolium frameworks: direct analogues of metal azolate frameworks with charge-inverted node-and-linker structure

Transcription

1 Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2015 Electronic Supplementary Information Supramolecular imidazolium frameworks: direct analogues of metal azolate frameworks with charge-inverted node-and-linker structure Cristina Mottillo, Tomislav Friščić* Department of Chemistry, McGill University, Montreal, Canada, H3A 0B8

2 1. Experimental Details 1.1 General details Reagents 2-ethylimidazole (HEtIm), benzimidazole (HBim), 2-methylbenzimidazole (HMeBim), 2-phenylbenzimidazole (HPhBim), were purchased from Sigma Aldrich and used without purification. Solvents acetonitrile (ACN), methanol (MeOH), anhydrous ethanol (EtOH), N,Ndimethylformamide (DMF), dimethylsulfoxide (DMSO), acetone, H 2 SO 4 (99.99%), and H 2 SeO 4 (40%) were obtained from Fisher and used without further purification. 1.2 Instrumentation Single crystal X-ray diffraction Single crystal X-ray diffraction data was collected on a Bruker APEX II diffractometer with MoKα (λ= Å) source and CCD detector at 100 K, unless otherwise specified. The structures were determined by least squares refinement against F 2 using SHELX-2014 software Powder X-ray Diffraction (PXRD) Powder X-ray diffraction patterns were collected using a Bruker D2 powder diffractometer equipped with a Cu-K α (λ= Å) source and Lynxeye detector set at a discriminant range of V to V. The patterns were collected in the range of 3 to 40. Analysis of PXRD patterns was conducted using Panalytical X Pert Highscore Plus software. Experimental patterns were compared to simulated patterns calculated from published crystal structures using Mercury crystal structure viewing software. Crystallographic Information Files containing published crystal structures were obtained from the Cambridge Structural Database (CSD) and Crystallography Open Database (COD) Fourier-transform infrared attenuated total reflection (FTIR-ATR) FTIR-ATR spectra were collected using a Bruker Vertex 70 FTIR-ATR spectrometer in the range 400 cm -1 to 4000 cm -1. FTIR spectra were analysed using Bruker OPUS software Thermogravimetric analysis (TGA) Thermograms were collected using a TA Instruments TGA Q500 thermogravimetric analyser, at a heating rate of 10 C/min from 25 C to 800 C under dynamic atmosphere of nitrogen or air. The flow rates of the purge gas and sample gas were set at 50 ml/min and 50 ml/min respectively. TGA curves were analysed with TA Universal Analysis software Solid-state 15 N CP-MAS NMR (ssnmr) Natural abundance 15 N ssnmr spectra were collected on a 400 MHz Varian VNMR equipped with a 7.5 mm CP-MAS probe. All spectra were collected at a spin rate of 5 khz with a contact time of 2 ms and a recycle delay of 2 s. NMR spectra were analysed using MestreNova software. 1.3 Synthesis of imidazolium salts (H 2 Etim) 2 SO 4 : 2-ethylimidazole (16 mmol, g) was dissolved in EtOH. H 2 SO 4 (8 mmol, ml) was added dropwise. A 10 ml aliquot of the reaction mixture was dried under rotary evaporation, resulting in a viscous liquid. The formation of large, highly deliquescent diffraction-quality crystals was observed after 24 months in a closed vial. The resulting crystals were too deliquescent to be handled in air. As a result,

3 they were unsuitable for general solid-state analysis, and needed to be encased in epoxy glue for the duration of the diffraction experiment (H 2 Bim) 2 SO 4 : Benzimidazole (8 mmol, ) was dissolved in acetonitrile. H 2 SO 4 (4 mmol, ml) was added dropwise, inducing the formation of a white precipitate. The product was filtered, washed three times with acetonitrile, dried over vacuum filtration, and analyzed by PXRD, FTIR-ATR, TGA, 15 N ssnmr, and nitrogen BET sorption measurements. Diffraction-quality crystals were obtained by recrystallizing the product in MeOH upon cooling (H 2 MeBim) 2 SO 4 : 2-methylbenzimidazole (4 mmol, g) was dissolved in acetonitrile. H 2 SO 4 (2 mmol, ml) was added dropwise, inducing the formation of a white precipitate. The product was filtered, washed three times with acetonitrile, and dried over vacuum filtration. Diffraction-quality crystals were obtained by recrystallizing the product in DMF upon cooling. These crystals were ground in a mortar and pestle and analyzed by PXRD, FTIR-ATR, and TGA (H 2 PhBim) 2 SO 4 EtOH: 2-phenylbenzimidazole (4 mmol, g) was dissolved in acetonitrile. H 2 SO 4 (2 mmol, ml) was added dropwise, inducing the formation of a beige precipitate. The product was filtered, washed three times with acetonitrile, and dried over vacuum filtration. Diffraction-quality crystals were obtained by recrystallization in EtOH upon cooling. The crystals of rapidly decomposed upon removal from their mother liquor, making them unsuitable for further solid-state analysis. X-ray diffraction of ten crystals selected from the same vial revealed the same unit cell parameters and Bravais lattice as the reported structure (H 2 PhBim) 2 SO 4 2MeOH: 2-phenylbenzimidazole (4 mmol, g) was dissolved in acetonitrile. H 2 SO 4 (2 mmol, ml) was added dropwise, inducing the formation of a beige precipitate. The product was filtered, washed three times with acetonitrile, and dried over vacuum filtration. Diffraction quality crystals were obtained by recrystallization in MeOH upon cooling. The crystals of rapidly decomposed upon removal from their mother liquor, making them unsuitable for further solid-state analysis. X-ray diffraction of ten crystals selected from the same vial revealed they possessed the same unit cell parameters and Bravais lattice as the reported structure (H 2 Bim) 2 SeO 4 : Benzimidazole (4 mmol, g) was dissolved in acetonitrile. Selenic acid 2 mmol, ml) was added dropwise to form a white precipitate. The precipitate was filtered over vacuum and washed three times with acetonitrile. The product was analyzed by PXRD, FTIR-ATR, TGA, and 15 N ssnmr. Diffraction-quality crystals were obtained by recrystallizing in MeOH upon cooling. Heat should be avoided in the synthesis and recrystallization of selenate salts, due to potential reduction of the selenate anion.

4 1.3.7 (H 2 MeBim) 2 SeO 4 MeOH 0.5H 2 O: 2-Methylbenzimidazole (4 mmol, g) was dissolved in MeOH. Selenic acid (2 mmol, ml) was added dropwise, after which the addition of adequate amounts of acetonitrile induced the precipitation of a white solid. The product was filtered, washed three times with acetonitrile, and dried over vacuum. Diffraction-quality crystals were obtained by recrystallization in MeOH and acetone upon cooling, ground, and subsequently analyzed by PXRD while still in their mother liquor. The crystals decomposed upon removal from their mother liquor, making them unsuitable for further solid-state analysis. X-ray diffraction of ten crystals selected from the same vial revealed they possessed the same unit cell parameters and Bravais lattice as the reported structure (H 2 PhBim) 2 SeO 4 : 2-phenylbenzimidazole (4 mmol, g) was dissolved in MeOH. Selenic acid (2 mmol, ml) was added dropwise, after which the addition of adequate amounts of acetonitrile induced the precipitation of a white solid. The product was filtered, washed three times with acetonitrile, and dried over vacuum. Diffraction-quality crystals were obtained by recrystallization in DMSO upon cooling. Crystals were ground in their mother liquor by mortar and pestle and analyzed by PXRD. They decomposed upon removal from their mother liquor, making them unsuitable for further solid-state analysis. X-ray diffraction of ten crystals selected from the same vial revealed they possessed the same unit cell parameters and Bravais lattice as the reported structure (H 2 PhBim) 2 SeO 4 ) 2MeOH: 2-phenylbenzimidazole (4 mmol, g) was dissolved in MeOH. Selenic acid (2 mmol, ml) was added dropwise, after which the addition of adequate amounts of acetonitrile induced the precipitation of a white solid. The product was filtered, washed three times with acetonitrile, and dried over vacuum. Diffraction-quality crystals were obtained by recrystallization in MeOH upon cooling. Crystals were ground in their mother liquor by mortar and pestle and analyzed by PXRD. They decomposed upon removal from their mother liquor, making them unsuitable for further solid-state analysis. X-ray diffraction of ten crystals selected from the same vial revealed they possessed the same unit cell parameters and Bravais lattice as the reported structure.

5 2. General Crystallographic data 2.1 General crystallographic data for (H 2 Etim) 2 SO 4 : Formula C 10 H 16 N 4 O 4 S M r Crystal system Monoclinic a/å 9.642(11) b/å (17) c/å 9.334(10) V/Å (3) T/K 293(2) Space group C2/c Z 4 Radiation type MoK α μ/mm No. of reflections measured 7178 No. of independent reflections 1484 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S General crystallographic data for (H 2 Bim) 2 SO 4 : Formula C 14 H 14 N 4 O 4 S M r Crystal system Orthorhombic a/å (8) b/å (14) c/å (7) V/Å (4) T/K 293(2) Space group Fdd2 Z 8 Radiation type MoK α μ/mm No. of reflections measured 9359 No. of independent reflections 1962 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S 1.069

6 2.3 General crystallographic data for (H 2 MeBim) 2 SO 4 : Formula C 16 H 18 N 4 O 4 S M r Crystal system Monoclinic a/å (3) b/å (11) c/å (2) V/Å (4) T/K 293(2) Space group C2/c Z 4 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 2143 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S General crystallographic data for (H 2 PhBim) 2 SO 4 EtOH: Formula C 26 H 22 N 4 O 4 S C 2 H 6 O M r Crystal system Orthorhombic a/å (4) b/å 8.218(2) c/å (5) V/Å (11) T/K 100(2) Space group Pbcn Z 4 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 2314 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S 1.095

7 2.5 General crystallographic data for (H 2 PhBim) 2 SO 4 2MeOH: Formula C 26 H 22 N 4 O 4 S 2(C 2 H 4 O) M r Crystal system Orthorhombic a/å (4) b/å (18) c/å (4) V/Å (10) T/K 100(2) Space group Pbcn Z 4 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 2444 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S General crystallographic data for (H 2 Bim) 2 SeO 4 : Formula C 14 H 14 N 4 O 4 Se M r Crystal system Tetragonal a/å (19) b/å (19) c/å (2) V/Å (12) T/K 100(2) Space group P Z 16 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 6722 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S 1.034

8 2.7 General crystallographic data for (H 2 MeBim) 2 SeO 4 MeOH 0.5H 2 O: Formula C 16 H 18 N 4 O 4 Se CH 4 O 0.5(H 2 O) M r Crystal system Monoclinic a/å (2) b/å (7) c/å (14) V/Å (5) T/K 100(2) Space group C2/c Z 8 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 4797 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S General crystallographic data for (H 2 PhBim) 2 SeO 4 : Formula C 26 H 22 N 4 O 4 Se M r Crystal system Triclinic a/å 9.611(4) b/å (4) c/å (5) V/Å (8) T/K 100(2) Space group P-1 Z 2 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 4683 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S 1.003

9 2.9 General crystallographic data for (H 2 PhBim) 2 SeO 4 ) 2MeOH: Formula C 26 H 26 N 4 O 4 Se 2(CH 4 O) M r Crystal system Orthorhombic a/å (12) b/å (6) c/å (14) V/Å (3) T/K 100(2) Space group Pbcn Z 4 Radiation type MoK α μ/mm No. of reflections measured No. of independent reflections 2818 R int R 1 (for I > 2σ(I)) wr(f 2 ) (for I > 2σ(I)) R 1 (all data) wr(f 2 ) (all data) S 1.043

10 3. Crystal structures Figure S1. Ethyl groups of adjacent ligands (shown in space filling) pointing into voids in 2- dimensional 4,4-nets formed by 2-ethylimidazolium sulfate (shown in wireframe). Figure S2. Methanol molecules (shown in space filling) separating 2-dimensional 4,4-nets (shown in wireframe) formed by 2-phenylbenzimidazolium sulfate methanol solvate

11 Figure S3. Ethanol molecules (shown in space filling) separating 2-dimensional 4,4-nets (shown in wireframe) formed by 2-phenylbenzimidazolium sulfate ethanol solvate Figure S4. Methanol molecules (shown in space filling) separating 2-dimensional 4,4-nets (shown in wireframe) formed by 2-phenylbenzimidazolium selenate methanol solvate

12 3. Selected powder X-ray diffraction data a) b) c) d) 2θ/º Figure S5. Powder X-ray diffraction data of sulfate and selenate salts derived from benzimidazole: a) Bulk (H 2 Bim) 2 SO 4 powder, crystallized from acetonitrile; b) simulated pattern for (H 2 Bim) 2 SO 4 ; c) bulk (H 2 Bim) 2 SeO 4 powder crystallized from acetonitrile, d) simulated pattern for (H 2 Bim) 2 SeO 4.

13 a) b) c) d) 2θ/º Figure S6. Powder X-ray diffraction data of sulfate and selenate salts derived from 2- methylbenzimidazole: a) single crystals of (HMeBim) 2 SO 4 crystallized from DMF, dried in air and ground; b) simulated pattern for (H 2 MeBim) 2 SO 4 ; c) single crystals of (H 2 MeBim) 2 SeO 4 MeOH 0.5H 2 O crystallized from MeOH and acetone, ground and recorded while in mother liquor; d) simulated pattern for (H 2 MeBim) 2 SeO 4 MeOH 0.5H 2 O.

14 a) b) c) d) e) f) 2θ/º Figure S7. Powder X-ray diffraction data of sulfate and selenate salts derived from 2- phenylbenzimidazole: a) simulated pattern for (H 2 PhBim) 2 SO 4 EtOH; b) simulated pattern for (H 2 PhBim) 2 SO 4 2MeOH; c) single crystals of (H 2 PhBim) 2 SeO 4 crystallized from DMSO, recorded in mother liquor; d) simulated pattern for (H 2 PhBim) 2 SeO 4 ; e) single crystals of (H 2 PhBim) 2 SeO 4 2MeOH crystallized from MeOH, recorded in mother liquor and f) simulated pattern for (H 2 PhBim) 2 SeO 4 2MeOH.

15 3. Thermogravimetric Analysis Figure S8. Thermogravimetric analysis of bulk (H 2 Bim) 2 SO 4 in air. The relative sizes of TGA steps suggest the first step in decomposition is loss of one equivalent of HBim (expected loss: 35.3%; experimental mass loss in the first step: 36.3%),

16 Figure S9. Thermogravimetric analysis of (H 2 MeBim) 2 SO 4 single crystals crystallized from DMF, dried in air and manually ground. Thermogram recorded in nitrogen. The relative sizes of TGA steps suggest the first step in decomposition is loss of one equivalent of HMeBim (expected loss: 36.5%; experimental mass loss in the first step: 38.4%),

17 Figure S10. Thermogravimetric analysis of (H 2 Bim) 2 SeO 4 in nitrogen. The steps in the thermogram cannot be readily associated with simple loss of either HBim or H 2 SeO 4 components, probably due to the thermal instability and oxidising properties of the selenate ion.

18 4. Solid-state 15 N CP-MAS NMR data ppm Figure S11. Solid-state 15 N CP-MAS NMR spectra of HBim, (H 2 Bim) 2 SO 4, and (H 2 Bim) 2 SeO 4.

19 5. FTIR-ATR data Wavenumber (cm -1 ) Figure S12. FTIR data of sulfate and selenate salts derived from benzimidazole: a) HBim b) Bulk (H 2 Bim) 2 SO 4 powder, c) Bulk (H 2 Bim) 2 SeO 4 powder. Wavenumber (cm -1 ) Figure S13. FTIR data of sulfate salt derived from 2-methylbenzimidazole: a) HMeBim, b) Single crystals of (H 2 MeBim) 2 SO 4, dried in air and manually ground.

20 5. Nitrogen sorption isotherms (Brunauer-Emmett-Teller) 10 N2 adsorbed (cm3/g STP) P/Pº Figure S14. Nitrogen adsorption isotherm of (H 2 Bim) 2 SO 4 bulk powder. The material exhibits no porosity.