(Supporting Information) Porosity Prediction through Hydrogen Bonding in Covalent Organic Frameworks

Transcription

1 (Supporting Information) Porosity Prediction through Hydrogen Bonding in Covalent Organic Frameworks Suvendu Karak, 1,2 Sushil Kumar, 2 Pradip Pachfule 2 and Rahul Banerjee 2,3,* 1 Academy of Scientific and Innovative Research, New Delhi, India. 2 Physical /Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune , India. 3 Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur , India. * r.banerjee@ncl.res.in; Tel: S1

2 Table of Contents Section Page No S-1 Materials and Instrumentation S3 S-2 Synthetic procedures S5 S-3 Powder X-Ray Diffraction and Scherrer s Analysis S18 S-4 FTIR spectra S23 S-5 Nitrogen adsorption analysis S27 S-6 Pore size distribution for COFs S38 S-7 Measurement of average of hydrogen bonding distances [d avg (N amine H O acid )] in the acid-diamine salts S43 S-8 Mechanism of COF synthesis S48 S-9 Measurement of average N amine O acid distances (D avg ) S51 S-10 Pawley refinement and fractional atomic coordinates S53 S-11 TG analyses S64 S-12 SEM and TEM analyses S65 S C CP-MAS spectra S67 S-14 References S68 S2

3 Section S1: Materials and Instrumentation Materials The starting materials 1,3,5 triformylphloroglucinol (Tp) and 2,2-bipyridine-5,5'-diamine (Bpy) were synthesized in the lab following the previous literature protocols. 1,2 All commercially available reagents and solvents were used without further purification. All the commercially available materials were bought from Sigma-Aldrich, TCI chemicals, Avra Chemicals and Fisher Scientific depending upon their availability. General instrumentations and methods Powder X-ray diffraction (PXRD) data were collected using a Rigaku, MicroMax-007HF with high-intensity Microfocus rotating anode X-ray generator. All the COFs were recorded in the 2θ range between 2 40 and data was collected with the help of Control Win software. The radiation used was Cu Kα ( = 1.54 Å) with a Ni filter, and the data collection was carried out using an Aluminium holder at a scan speed of 1 min -1 and a step size of Fourier transform infrared (FT-IR) spectra were obtained using a Bruker Optics ALPHA- E spectrometer with a universal Zn-Se ATR (attenuated total reflection) accessory. FT-IR data are reported with a wave number (cm 1 ) scale. Thermogravimetric analyses (TGA) were carried out on a TG50 analyzer (Mettler-Toledo) and a SDT Q600 TG-DTA analyzer under N 2 atmosphere at a heating rate of 10 ºC min 1 within a temperature range of C. Scanning Electron Microscopy (SEM) measurements were executed with a Zeiss DSM 950 scanning electron microscope and FEI, QUANTA 200 3D Scanning Electron Microscope equipped with tungsten filament as electron source operated at 10 kv. The samples were prepared simply by putting a drop of COFs dispersed in isopropanol on a clean piece of Silicon wafer. To avoid charging during SEM analyses, we coated all the COFs samples with a thin layer of gold by a SCD 040 Balzers Union prior to analyses. Transmission Electron Microscopy (TEM) analyses were performed using a FEI Tecnai G2 F20 X-TWIN TEM at an accelerating voltage of 200 kv. The TEM Samples were S3

4 prepared for analyses by drop casting the samples (dispersed in isopropanol) on copper grids TEM Window (TED PELLA, INC. 200 mesh). N 2 adsorption analyses were performed at 77 K using a liquid nitrogen bath (77 K) on a Quantachrome Quadrasorb automatic volumetric instrument. All the COFs samples were outgassed for 12 h at 120 C under vacuum prior to the gas adsorption studies. The surface areas were evaluated using Brunauer-Emmett-Teller (BET) model applied between P/P 0 values of 0.05 and 0.3 for mesoporous COFs. The pore size distributions were calculated using the non-localized density functional theory (NLDFT) method. The surface area of each of the COF has been measured multiple times and then averaged out for proper comparison. Solid state NMR spectra were recorded (SSNMR) on Bruker 300 MHz NMR spectrometer. Carbon chemical shifts are expressed in parts per million (δ scale). Single-crystal X-ray diffraction data were collected with a Super Nova Dual source X-ray Diffractometer system (Agilent Technologies) having a CCD area detector and operated at 250 W power (50 kv, 0.8 ma) to generate Mo Kα radiation (λ = Å) and Cu Kα radiation (λ = Å) at 298 K. PTSA-Pa-2, NBSA-Pa-1, PSA-Pa-1, BSA-Pa-1 crystals were placed on top of a nylon Cryoloop (Hampton research) and then mounted in the diffractometer. Samples were initially scanned to obtain preliminary unit cell parameters and to assess the mosaicity (breadth of spots between frames) of the crystal. CrysAlis Pro program software was used suite to carry out overlapping φ and ω scans at detector (2θ) settings (2θ = 28). After the data collection, all the reflections were sampled from all regions of the Ewald sphere to re-determine the unit cell parameters for data integration. CrysAlis Pro software was also used for the data integration with a narrow frame algorithm. SCALE3 ABSPACK 3 scaling algorithm program was used for the subsequent data correction for adsorption. These structures were solved by a direct method and refined using the SHELXL software suite. Atoms were located from an iterative examination of difference F-maps following least-squares refinements of the earlier models. The final model was refined anisotropically (if the number of data permitted) until full convergence was achieved. Hydrogen atoms were placed geometrically and placed in a riding model. The structure was examined using the ADDSYM subroutine of PLATON 5 to assure that no additional symmetry could be applied to the models. The ellipsoids in ORTEP diagrams are displayed at the 50% probability level unless noted. S4

5 Section S2: Synthetic Procedures Synthesis of acid-diamine salt crystals. 0.9 mmol of acid [PTSA, mg; NBSA, mg; PSA, mg; BSA, mg; ABSA, mg] was taken in a mortar. Then 0.45 mmol of corresponding diamine [p-phenylenediamine (Pa-1, 48.6 mg); 2,5-dimethyl-pphenylenediamine (Pa-2, 61.3 mg); 2-nitro-1,4-phenelynediamine (Pa-NO 2, 68.9 mg); 2,5- dichloro-p-phenylenediamine (Pa-Cl 2, 79.6 mg); 2-chloro-5-nitro-p-phenylenediamine (Pa- Cl-NO 2, 84.4 mg); 3,3 -dimethylbenzidine (BD-Me 2, 95.5 mg) ; 3,3 -dimethoxybenzidine {BD-(OMe) 2, mg}; 2,2'-bipyridine-5,5'-diamine (Bpy, 83.8 mg); 3,3',5,5'- tetramethylbenzidine (BD-Me 4, mg) ; 2,4,6-triaminopyrimidine (Pym, 56.3 mg) 3,3'- dihydroxybenzidine {BD-(OH) 2, mg}] was added. Both acid and diamine were mixed thoroughly to powder with a mortar-pestle. The powder was then dissolved in a minimal amount of suitable solvents such as methanol, methanol-water (1:1) and DMF (Table S1). The pure crystals of appropriate size were recovered from either slow evaporation or vapor diffusion of diethyl ether for single crystal X-ray diffraction. The acid-diamine salts were dried under vacuum for 1 h before they were used for the syntheses of covalent organic frameworks. Table S1 Solvent combinations for the crystallization of acid-diamine salts. S. No. Acid-diamine salt Solvent Crystallization method PTSA-Pa-Cl 2, PSA-Pa-Cl 2, BSA-Pa- 1. Cl 2, NBSA-Pa-Cl 2, PTSA-Pa-Cl- NO 2, PSA-Pa-Cl-NO 2, BSA-Pa-Cl- MeOH Vapour diffusion of diethyl ether NO 2, NBSA-Pa-Cl-NO 2 PSA-Pa-2, BSA-Pa-2, NBSA-Pa-2, BSA-Pa-NO 2, PSA-Pa-NO 2, NBSA- 2. Pa-NO 2, NBSA-BD-(OMe) 2, ABSA- BD-(OMe) 2, BSA-BD-(OMe) 2, PSA- BD-(OMe) 2, PTSA-BD-Me 2, NBSA- MeOH:H 2 O (1:1) Slow evaporation BD-Me 2, NBSA-BD-(OH) 2, BSA- BD-(OH) 2, PSA-BD-(OH) 2, ABSA- Pa-NO 2, PSA-BD-Me 4, BSA-BD- S5

6 Me 4, PTSA-BD-Me 4, NBSA-BD- Me 4, PTSA-Pym, BSA-Pym, NBSA- Pym, NBSA-Bpy Figure S1 Digital images of crystallized salts. Few among the 52 salts have been shown as representative. Table S2 Crystal data collection and structure refinement parameters. BSA-BD-Me4 BSA-pym PTSA-pym PTSA-BD-Me4 Empirical formula C 28 H 32 N 2 O 6 S 2 C 16 H 26 N 5 O 8 S 2 C 18 H 23 N 5 O 6 S 2 C 30 H 36 N 2 O 6 S 2 Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Crystal system Monoclinic Triclinic Monoclinic Monoclinic Space group C 2/c P -1 I 2/a P 2 1 /n a (13) Å (15) Å (7) Å (10) Å b (5) Å (12) Å (4) Å (3) Å c (19) Å (19) Å (12) Å (12) Å (13) (6) (13) (5) (6) S6

7 (12) Volume (4) Å (3) Å (2) Å (3) Å 3 Z Density (calculated) Mg/m Mg/m Mg/m Mg/m 3 Absorption mm mm mm mm -1 coefficient F(000) Crystal size x x mm x x mm x x mm x x mm 3 Theta range for data to to to to collection Index ranges -17 h 18, -8 k 8, -28 l h 8, -12 k 12, -14 l h 13, -6 k 9, -26 l h 20, -8 k 8, -25 l 26 Reflections collected Independent reflections 2356 [R(int) = ] 3884 [R(int) = ] 1858 [R(int) = ] 4984 [R(int) = ] Data Completeness 99.9 % 99.8 % 99.7 % 99.9 % Absorption correction Max. and min and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 2356 / 4 / / 1 / / 1 / / 4 / 434 parameters Goodness-of-fit on F 2 Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å -3 PTSA-Pa-Cl- NO2 PTSA-Pa-Cl2 NBSA-Pa-NO2 NBSA-BD-OMe2 NBSA-BD-Me2 Empirical formula C 13 H 14 ClN 3 O 5 S C 10 H 11 ClNO 3 S C 12 H 12 N 4 O 7 S C 26 H 26 N 4 O 12 S 2 C 27 H 30 N 4 O 11 S 2 Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Å Crystal system Monoclinic Monoclinic Monoclinic Triclinic Triclinic Space group P 2 1 /c P 2 1 /n P 2 1 /c P -1 P -1 a (9) Å (2) Å (3) Å (6) Å (5) Å b (14) Å (4) Å (15) Å (8) Å (5) Å c (2) Å (3) Å (8) Å (12) Å (5) Å (7) (5) (14) (2) (6) (8) (5) (7) (5) S7

8 Volume (4) Å (5) Å (16) Å (12) Å (11) Å 3 Z Density Mg/m Mg/m Mg/m Mg/m Mg/m 3 (calculated) Absorption coefficient mm mm mm mm mm -1 F(000) Crystal size x x mm x x mm x x mm x x mm x x mm 3 Theta range for to to to to to data collection Index ranges -8 h 8, -10 k 17, -18 l 17-7 h 7, -18 k 10, -14 l 12-6 h 4, -21 k 10, -17 l 17-7 h 7, -10 k 11, -14 l 9-12 h 12, -10 k 13, -14 l 15 Reflections collected Independent reflections 2814 [R(int) = ] 1959 [R(int) = ] 2487 [R(int) = ] 2507 [R(int) = ] 5133 [R(int) = ] Data 98.0 % 99.9 % 97.9 % 99.8 % 99.8 % Completeness Absorption Multi-scan Multi-scan Multi-scan Multi-scan Multi-scan correction Max. and min and and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 2814 / 0 / / 0 / / 0 / / 1 / / 0 / 414 parameters Goodness-of-fit Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å and e.å -3 PSA-BD-(OH)2 BSA-Pa-NO2 PSA-Pa-NO2 NBSA-Pa-Cl2 Empirical formula C 24 H 26 N 2 O 11 S 2 C 12 H 13 N 3 O 5 S C 12 H 13 N 3 O 6 S C 12 H 11 C l2 N 3 O 5 S Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Crystal system Monoclinic Monoclinic Monoclinic Monoclinic Space group P 2 1 /c P 2 1 /n P 2 1 /c C 2/c a (3) Å (3) Å (10) Å (7) Å b (2) Å (11) Å (11) Å (3) Å c (5) Å (5) Å (3) Å (6) Å (2) (4) (15) (3) Volume (10) Å (13) Å (3) Å (19) Å 3 Z S8

9 Density (calculated) Mg/m Mg/m Mg/m Mg/m 3 Absorption mm mm mm mm -1 coefficient F(000) Crystal size x x mm x x mm x x mm x x mm 3 Theta range for data to to to to collection Index ranges -15 h 14, -8 k 8, -29 l 31-8 h 7, -17 k 15, -11 l 14-8 h 8, -9 k 9, -27 l h 24, -6 k 8, -22 l 22 Reflections collected Independent reflections 4480 [R(int) = ] 2363 [R(int) = ] 2434 [R(int) = ] 2685 [R(int) = ] Data Completeness 99.9 % 99.9 % 99.7 % 99.7 % Absorption Multi-scan Multi-scan Multi-scan Multi-scan correction Max. and min and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 4480 / 0 / / 0 / / 0 / / 1 / 228 parameters Goodness-of-fit on F 2 Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å -3 BSA-Pa-Cl 2 PSA-Pa-Cl 2 BSA-Pa-2 PSA-Pa-2 ABSA-Pa-NO 2 Empirical C 21 H 21 Cl 3 N 3 O 6 S 2 C 9 H 9 ClNO 4 S C 10 H 12 NO 3 S C 10 H 12 NO 4 S C 18 H 21 N 5 O 8 S 2 formula Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Å Crystal system Triclinic Monoclinic Monoclinic Monoclinic Orthorhombic Space group P -1 P 21/c P 21/n P 21/c P b c a a (6) Å (3) Å (2) Å (2) Å (3) Å b (7) Å (3) Å (2) Å (2) Å (3) Å c (8) Å (9) Å (5) Å (7) Å (8) Å (5) (5) (3) (3) (3) (5) Volume (14) Å (8) Å (5) Å (6) Å (19) Å 3 Z Density (calculated) Mg/m Mg/m Mg/m Mg/m Mg/m 3 S9

10 Absorption coefficient mm mm mm mm mm -1 F(000) Crystal size x x mm x x mm x x mm x x mm x 0.23 x 0.19 mm 3 Theta range for to to to to to data collection Index ranges -12 h 11, -12 k 12, -14 l 14-8 h 9, -6 k 4, -26 l h 10, -8 k 7, -20 l 13-9 h 9, -6 k 6, -27 l h 7, -16 k 14, -35 l 33 Reflections collected Independent reflections 4373 [R(int) = ] 1841 [R(int) = ] 1853 [R(int) = ] 1883 [R(int) = ] 3679 [R(int) = ] Data 99.8 % 99.9 % 99.8 % 99.9 % 99.8 % Completeness Absorption Multi-scan Multi-scan Multi-scan Multi-scan Multi-scan correction Max. and min and and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 4373 / 1 / / 0 / / 0 / / 0 / / 1 / 338 parameters Goodness-of-fit Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å and e.å -3 NBSA-Pa-Cl- NO2 BSA-Pa-Cl-NO2 NBSA-pym PSA-Pa-Cl-NO2 BSA-BD(OH)2 Empirical formula C 12 H 10 ClN 4 O 7 S C 12 H 12 ClN 3 O 5 S C 16 H 17 N 7 O 10 S 2 C 12 H 12 ClN 3 O 6 S C 24 H 26 N 2 O 9 S 2 Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Å Crystal system Triclinic Orthorhombic Triclinic Triclinic Triclinic Space group P -1 P c c n P -1 P -1 P -1 a (4) Å (6) Å (5) Å (5) Å (5) Å b (5) Å (4) Å (10) Å (4) Å (9) Å c (7) Å (3) Å (7) Å (9) Å (10) Å (5) (7) (5) (6) (4) (5) (6) (5) (4) (6) (5) (6) Volume (8) Å (15) Å (14) Å (8) Å (15) Å 3 Z Density (calculated) Mg/m Mg/m Mg/m Mg/m Mg/m 3 Absorption coefficient mm mm mm mm mm -1 F(000) S10

11 Crystal size Theta range for data collection Index ranges x x x x x x x x x x mm mm mm mm mm to to to to to h 8, -11 k 11, -11 l h 24, -10 k 16, -11 l 10-9 h 8, -11 k 13, -12 l 14-8 h 8, -7 k 10, -14 l 14-9 h 9, -14 k 14, -12 l 15 Reflections collected Independent reflections 2657 [R(int) = ] 2557 [R(int) = ] 3648 [R(int) = ] 2602 [R(int) = ] 4340 [R(int) = ] Data 99.7 % 99.5 % 99.8 % 99.8 % 99.8 % Completeness Absorption Multi-scan Multi-scan Multi-scan Multi-scan Multi-scan correction Max. and min and and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 2657 / 1 / / 1 / / 0 / / 1 / / 0 / 377 parameters Goodness-of-fit Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å and e.å -3 NBSA-pym NBSA-Pa-2 PTSA-BD(Me)2 NBSA-Pa-1 PSA-BD-Me4 Empirical formula C 16 H 15 N 5 O 5 S C 10 H 11 N 2 O 5 S C 58 H 64 N 4 O 13 S 4 C 9 H 9 N 2 O 5 S C 28 H 32 N 2 O 8 S 2 Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Å Crystal system Triclinic Monoclinic Monoclinic Triclinic Monoclinic Space group P -1 I 2/a C 2/c P -1 C 2/c a (3) Å (12) Å (5) Å (5) Å (9) Å b (5) Å (4) Å (11) Å (10) Å (14) Å c (8) Å (14) Å (7) Å (10) Å (6) Å (5) (8) (4) (8) 90.53(2) (8) (3) (4) (9) 90 Volume (8) Å (3) Å (18) Å (9) Å (16) Å 3 Z Density (calculated) Mg/m Mg/m Mg/m Mg/m Mg/m 3 Absorption coefficient mm mm mm mm mm -1 F(000) Crystal size x x mm x x mm x x mm x 0.20 x 0.18 mm x x mm 3 Theta range for to to to to to S11

12 data collection Index ranges -8 h 5, -11 k 11, -15 l h 21, -7 k 7, -22 l h 31, -8 k 8, -35 l 19-6 h 6, -10 k 10, -9 l h 32, -8 k 8, -18 l 18 Reflections collected Independent reflections 2943 [R(int) = ] 1925 [R(int) = ] 4736 [R(int) = ] 1847 [R(int) = ] 2316 [R(int) = ] Data 99.9 % 99.8 % 94.0 % 99.7 % 99.8 % Completeness Absorption Multi-scan Multi-scan Multi-scan Multi-scan Multi-scan correction Max. and min and and and and and transmission Refinement method Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Data / restraints / 2943 / 0 / / 0 / / 9 / / 0 / / 0 / 183 parameters Goodness-of-fit Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å and e.å -3 BSA-BD-OMe2 NBSA-BD(OH)2 NBSA-BD-Me4 PTSA-BD-OMe2 Empirical formula C 26 H 28 N 2 O 8 S 2 C 24 H 22 N 4 O 12 S 2 C 28 H 32 N 4 O 11 S 2 C 28 H 32 N 2 O 8 S 2 Formula weight Temperature 293(2) K 293(2) K 293(2) K 293(2) K Wavelength Å Å Å Å Crystal system Monoclinic Monoclinic Triclinic Monoclinic Space group P 2 1 /n P 2 1 /n P -1 C 2/c a (6) Å (9) Å (15) Å (14) Å b (2) Å (5) Å (14) Å (3) Å c (11) Å (8) Å (17) Å (15) Å (10) (10) (6) (12) (6) (11) 90 Volume (2) Å (15) Å (4) Å (3) Å 3 Z Density (calculated) Mg/m Mg/m Mg/m Mg/m 3 Absorption coefficient mm mm mm mm -1 F(000) Crystal size x x mm x x mm x x mm x x mm 3 Theta range for data to to to to collection Index ranges -6 h 6, -24 k 23, -9 l h 15, -8 k 8, -16 l h 12, -13 k 13, -15 l h 25, -6 k 6, -27 l 26 Reflections collected Independent 2344 [R(int) = 2292 [R(int) = 5322 [R(int) = ] 2503 [R(int) = ] S12

13 reflections ] ] Data Completeness 99.8 % 99.9 % 99.8 % 99.8 % Absorption correction Multi-scan Multi-scan Multi-scan Multi-scan Max. and min. transmission and and and and Refinemen method Data / restraints / parameters Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares Full-matrix leastsquares 2344 / 1 / / 1 / / 0 / / 1 / 193 Goodness-of-fit Final R indices [I>2sigma(I)] a, b R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R1 = , wr2 = R indices (all data) R 1 = , wr 2 = R 1 = , wr 2 = R 1 = , wr 2 = R1 = , wr2 = Largest diff. peak and hole and e.å and e.å and e.å and e.å - 3 a R = ( Fo Fc )/ Fo ; b wr = { [w(f o 2 F c 2 ) 2 ]/ [w(f o 2 ) 2 ]} 1/2 Synthesis of COFs. Typically, 0.3 mmol (63 mg) of 1,3,5-triformylphloroglucinol (Tp) was taken in a mortar followed by the addition of 0.45 mmol of diamine [(diamine weight was calculated from salt s molecular weight) p-phenylenediamine, Pa-1; 2,5-dimethyl-pphenylenediamine, Pa-2; 2-nitro-1,4-phenylenediamine, Pa-NO 2 ; 2,5-dichloro-pphenylenediamine Pa-Cl 2 ; 2-chloro-5-nitro-p-phenylenediamine, Pa-Cl-NO 2 ; 3,3 - dimethylbenzidine, BD-Me 2 ; 3,3 -dimethoxybenzidine BD-(OMe) 2 ; 2,2'-bipyridine-5,5'- diamine, Bpy; 3,3',5,5'-tetramethylbenzidine, BD-Me 4 ; 2,4,6-triaminopyrimidine Pym and 3,3'-dihydroxybenzidine, BD-(OH) 2 ]. The reaction mixture was ground thoroughly with a pestle for 5 to 10 minutes. The certain color change (in most of the cases) confirms the progress of the reaction. Then μl of water was added dropwise to the mixture and then the mixture was ground again for another 5 minutes. The mixture of salt and aldehyde was transformed into the dough which is viscous in nature. The addition of water resulted in a certain color change from pale to deep color. The amount of water varies depending upon the relative humidity and the nature of the salt. In high humidity (80-90%), the salt absorbs moisture from the air and leaves the mixture in paste-like nature. Thus <50 μl of water addition is preferred at that condition. The mixture was transferred into a glass vial and heated for 12 h in an oven at 90 C. It produced a red colored solid product. The mixture was left for cooling to room temperature for around 30 minutes. The vial was then filled up with water for the removal of acid. The solid product was then treated several times with N,Ndimethylacetamide (DMAc), for the removal of residual oligomers and unreacted starting S13

14 materials. Then, water was again added to the vial to remove DMAc as both are miscible in nature. Finally, acetone was added to remove water and DMAc, if any, and then dried in a 60 C oven for 2 h under reduced pressure until further use (Figure S2). Variation of water content and temperature affect the properties (crystallinity and porosity) of the COF (Tables S3 and S4; Figures S4 and S5). Although there is no abrupt alteration of the COF properties, the visible change in surface area confirms the role of water as well as temperature in COF synthesis. Figure S2 Salt to COF formation. COFs have been synthesized following the sequential steps. Acid-diamine salts have been reacted with aldehyde with the addition of water. Heating followed by washing with DMAc, water and acetone results in crystalline and porous COFs. S14

15 Scheme S1 Schematic representation of COF synthesis using C 3 -symmetric acidtriamine salt. Figure S3 Synthesis of COFs via salt mediated crystallization. Firstly, amine and mineral acids have been crystallized. The crystals were further reacted with aldehyde to produce COFs. p-phenylene diamine has been drawn in black color. Common aldehyde Tp and acids are marked in red and green colors respectively. S15

16 Table S3 Surface area analysis of TpPa-1 (PTSA-Pa-1) COF based on temperature. Highest BET Highest BET Highest BET COF surface area (m 2 /g) (60 C, surface area (m 2 /g) (120 C, surface area (m 2 /g) (90 C, 12h) 12h) 12h) TpPa Table S4 Highest BET Surface area of TpPa-1 (PTSA-Pa-1) COF based on water content (RH = 35%) COF BET surface area (m 2 /g) (~100 μl) BET surface area (m 2 /g) (~250 μl) BET surface area (m 2 /g) (~500 μl) BET surface area (m 2 /g) (~1000 μl) TpPa Figure S4 Comparison of BET surface area with the variation of temperature and water content. S16

17 Figure S5 Comparison of PXRD patterns with the variation of a) temperature and b) water content during the synthesis of COFs. S17

18 Section S3: Powder X-Ray Diffraction and Scherrer s Analysis Figure S6 PXRD patterns of the COFs and the corresponding simulated structures. Various salts have been used to synthesize the COFs which result in different crystallinity of the COFs. The acids mentioned in the figures have been used to prepare the acid-diamine salts for a particular diamine. S18

19 Figure S7 PXRD patterns of the COFs and the corresponding simulated structures. Various salts have been used to synthesize the COFs which result in different crystallinity of the COFs. The acids mentioned in the figures have been used to prepare the acid-diamine salts for a particular diamine. The powder X-ray pattern with <100> diffraction peak has been used for the distinction of crystallinity of the as-synthesized COFs (Table S5). According to the intensity count, the comparison has been made. If we consider, e.g., TpPa-NO 2 COF, it exhibits PXRD intensity count (<100> plane) of 2540, 1685, 1330 and 3262 (intensity, a.u.) when it has been synthesized from BSA-Pa-NO 2, PSA-Pa-NO 2, NBSA-Pa-NO 2 and PTSA-Pa-NO 2 salts respectively. The count clearly shows that PTSA-Pa-NO 2 based COF has the highest crystallinity whereas NBSA-Pa-NO 2 produces the least crystalline COF. S19

20 Table S5 PXRD peak intensity count (<100> plane) of all the as-synthesized COFs from different salts. Salt Name Peak Intensity Peak Intensity Salt Name (a.u.) (a.u.) BSA-Pa-NO ABSA-BD-(OMe) PSA-Pa-NO NBSA-BD-Me NBSA-Pa-NO PTSA-BD-Me PTSA- Pa-NO HCl-BD-Me a ABSA-Pa-NO 2 - a BSA-BD-Me 4 - a NBSA-Pa-Cl 2 - PTSA-BD-Me BSA-Pa-Cl PSA-BD-Me PSA-Pa-Cl NBSA-Pa PTSA-Pa-Cl PTSA-Pa PTSA-Pa PSA-Pa BSA-Pa ABSA-Pa-1 a - PSA-Pa HCl-Pa NBSA-Pa TFA-Pa-1 - BSA-Pa-Cl-NO H 3 PO 4 -Pa PSA-Pa-Cl-NO H 2 SO 4 -Pa NBSA-Pa-Cl-NO Oxa-Pa PTSA-Pa-Cl-NO BSA-Pa NBSA-Bpy 675 PTSA-Bpy NBSA-Pym a - BSA-Pym a - a NBSA-BD-Me 4 - PTSA-Pym 295 HCl-BD-Me PTSA-BD-(OMe) BSA-BD-(OH) NBSA-BD-(OMe) NBSA-BD-(OH) BSA-BD-(OMe) a PSA-BD-(OH) 2 - a HCl-BD-(OMe) 2 - PTSA-BD-(OH) a The COF has intensity count of less than 200 (<100> plane) has not been mentioned herein. S20

21 However, as per reviewer s suggestion, the result has been further justified with Scherrer s analysis by achieving the domain size of the COF crystallites. The measurement has been done considering the Gaussian fitting of the high intense first peak (diffraction from <100> plane). The analysis depicts that the COF crystallites size could vary when a particular COF has been synthesized from different salts (Table S6). The Scherrer s equation can be written as: where: is the size of the ordered (crystalline) domains; is a dimensionless shape factor, with a value close to unity. The shape factor varies with the actual shape of the crystallite. Herein we have considered the shape factor as unity for the ease of calculation. λ is the X-ray wavelength which has the value Å; β is the line broadening at half of the maximum intensity (FWHM), after subtracting the instrumental line broadening, in radians. Silver behenate (C 22 H 44 O 2 Ag) was used to determine the instrumental peak broadening. and are the line broadening of the standard sample and COF samples respectively. θ is the Bragg angle (in degrees). Table S6 Domain size of the COF crystallites (Å) synthesized from different salts. Salt Name COF crystallite COF crystallite Salt Name size (Å) size (Å) BSA-Pa-NO ABSA-BD-(OMe) PSA-Pa-NO NBSA-BD-Me 2 91 NBSA-Pa-NO PTSA-BD-Me PTSA- Pa-NO HCl-BD-Me ABSA-Pa-NO BSA-Pa S21

22 NBSA-Pa-Cl NBSA-Pa BSA-Pa-Cl PTSA-Pa PSA-Pa-Cl PSA-Pa PTSA-Pa-Cl ABSA-Pa PTSA-Pa HCl-Pa BSA-Pa TFA-Pa PSA-Pa H 3 PO 4 -Pa NBSA-Pa H 2 SO 4 -Pa BSA-Pa-Cl-NO Oxa-Pa PSA-Pa-Cl-NO BSA-BD-Me NBSA-Pa-Cl-NO 2 - PTSA-BD-Me PTSA-Pa-Cl-NO PSA-BD-Me NBSA-Bpy 9.6 NBSA-BD-Me PTSA-Bpy HCl-BD-Me 4 - NBSA-Pym - BSA-BD-(OH) BSA-Pym - NBSA-BD-(OH) PTSA-Pym 44.0 PSA-BD-(OH) PTSA-BD-(OMe) PTSA-BD-(OH) NBSA-BD-(OMe) BSA-BD-(OMe) HCl-BD-(OMe) 2 - S22

23 Section S4: FTIR spectra Figure S8 FTIR spectra of the acid-diamine salts. S23

24 Figure S9 FTIR spectra of the as-synthesized COFs. FTIR spectra of as-synthesized COFs show the characteristic peaks corresponding to β-ketoenamine-linked framework structures. Both C=C and C-N peak regions have been highlighted for ready reference. S24

25 Figure S10 FTIR spectra of the as-synthesized COFs. FTIR spectra of as-synthesized COFs show the characteristic peaks corresponding to β-ketoenamine-linked framework structures. Both C=C and C-N peak regions have been highlighted for ready reference. S25

26 Figure S11 FTIR spectra of the as-synthesized COFs. FTIR spectra of as-synthesized COFs show the characteristic peaks corresponding to β-ketoenamine-linked framework structures. Both C=C and C-N peak regions have been highlighted for ready reference. S26

27 Figure S12 FTIR spectra of the as-synthesized COFs. FTIR spectra of as-synthesized COFs show the characteristic peaks corresponding to β-ketoenamine-linked framework structures. Both C=C and C-N peak regions have been highlighted for ready reference. Section S5: Nitrogen adsorption analysis BET theory is an extension of Langmuir theory, which gives the adsorption of gas molecule on monolayer s only. But BET theory explains the physical adsorption of gas molecules on a solid surface and serves as the basis for the measurement of the specific surface area of a material. The BET equation is, ( 0/ ) ( ) m 0 m Where p and p 0 are the equilibrium and the saturation pressure of adsorbents at the temperature of adsorption, v is the adsorbed gas quantity (for example, in volume units), and v m is the monolayer adsorbed gas quantity, c is the BET constant. S27

28 Table S7 Correlation coefficient (r) values of all the as-synthesized COFs. COF TpPa-NO 2 TpPa-Cl 2 TpPa-2 TpPa-Cl- NO 2 TpBpy TpPym Salts used Correlation Correlation COF Salts used coefficient coefficient BSA-Pa- NO TpBD- ABSA-BD- (OMe) 2 (OMe) PSA-Pa- NO NBSA-BD- NBSA-Pa- NO Me PTSA- Pa- NO TpBD-Me 2 PTSA-BD- Me ABSA-Pa- NO HCl-BD-Me NBSA-Pa- Cl BSA-Pa- Cl BSA-Pa PSA-Pa- Cl NBSA-Pa PTSA-Pa- Cl PTSA-Pa PTSA-Pa PSA-Pa BSA-Pa TpPa-1 ABSA-Pa PSA-Pa HCl-Pa NBSA-Pa TFA-Pa BSA-Pa-Cl-NO H 3 PO 4 -Pa PSA-Pa-Cl-NO H 2 SO 4 -Pa NBSA-Pa-Cl- NO Oxa-Pa PTSA-Pa-Cl BSA-BD- NO 2 Me 4 NBSA-Bpy PTSA-Bpy PTSA-BD- TpBD-Me 4 Me NBSA-Pym PSA-BD-Me BSA-Pym NBSA-BD- Me PTSA-Pym HCl-BD-Me S28

29 PTSA-BD- (OMe) BSA- BD(OH) TpBD TpBD- NBSA-BD- (OMe) 2 NBSA-BD- (OH) (OMe) (OH) 2 BSA-BD- (OMe) 2 PSA-BD- (OH) HCl-BD-(OMe) PTSA- BD- (OH) Figure S13 BET plot of COFs synthesized from different acid-diamine salts. S29

30 Figure S14 BET plot of COFs synthesized from different acid-diamine salts. S30

31 Figure S15 BET plot of COFs synthesized from different acid-diamine salts. S31

32 Figure S16 BET plot of COFs synthesized from different acid-diamine salts. S32

33 Figure S17 BET plot of COFs synthesized from different acid-diamine salts. S33

34 Figure S18 BET plot of COFs synthesized from different acid-diamine salts. S34

35 Figure S19 Nitrogen adsorption. COF synthesized from different acid-diamine salts results different surface area which has been reflected in their N 2 adsorption isotherms. The hydrogen bonding, d avg (N amine H O acid ), in the acid-diamine salts controls the reactivity of the salts with the aldehyde that further affects their properties. S35

36 Figure S20 Nitrogen adsorption. COF synthesized from different acid-diamine salts results different surface area which has been reflected in their N 2 adsorption isotherms. The hydrogen bonding, d avg (N amine H O acid ), in the acid-diamine salts controls the reactivity of the salts with the aldehyde that further affects their properties. Theoretical surface area of AA stacked structures was calculated using Zeo++ using a probe radius of 1.2 Å. 6,7 All the cifs were simulated by using Materials Studio. 8 In the case of TpBD-Me 2 and TpBpy COFs DFTB-optimised [1,2] AA stacked structures were used for theoretical surface area measurements. Table S8 Theoretical surface area of all the as-synthesized COFs. COF Unit Density: ASA_A^2: ASA_m^2/cm^3: ASA_m^2/g cell_volume: TpBD-(OH) TpBD-(OMe) TpBD-Me TpPa-Cl-NO S36

37 TpPa-NO TpBD-Me TpBpy TpPa TpPa TpPa-Cl TpPym Table S9 Surface area of all the as-synthesized COFs. COF TpPa-NO 2 TpPa-Cl 2 TpPa-2 TpPa-Cl- NO 2 TpBpy TpPym Salts used BET surface area (m 2 /g) COF BSA-Pa- NO TpBD-(OMe) 2 PSA-Pa- NO NBSA-Pa- NO 2 32 Salts used ABSA-BD- (OMe) 2 BET surface area (m 2 /g) TpBD-Me 2 PTSA- Pa- NO PTSA-BD-Me NBSA-BD-Me ABSA-Pa- NO 2 52 HCl-BD-Me 2 99 NBSA-Pa- Cl 2 20 BSA-Pa- Cl BSA-Pa PSA-Pa- Cl NBSA-Pa PTSA-Pa- Cl PTSA-Pa PTSA-Pa PSA-Pa BSA-Pa TpPa-1 ABSA-Pa-1 75 PSA-Pa HCl-Pa-1 20 NBSA-Pa TFA-Pa-1 14 BSA-Pa-Cl-NO H 3 PO 4 -Pa PSA-Pa-Cl-NO H 2 SO 4 -Pa NBSA-Pa-Cl-NO OA-Pa-1 36 PTSA-Pa-Cl-NO NBSA-Bpy 136 BSA-BDMe PTSA-Bpy 2336 PTSA-BD-Me TpBD-Me 4 NBSA-Pym 60 PSA-BD-Me BSA-Pym 345 NBSA-BD-Me 4 96 PTSA-Pym 408 HCl-BD-Me 4 73 S37

38 TpBD- (OMe) 2 PTSA-BD-(OMe) BSA-BD(OH) NBSA-BD-(OMe) HCl-BD-(OMe) 2 34 TpBD- 361 BSA-BD-(OMe) (OH) 2 PSA-BD-(OH) NBSA-BD- (OH) 2 PTSA- BD- (OH) Section S-6: Pore size distribution of COFs Figure S21 Pore size distribution of COFs. Pore size distributions of COFs calculated using the non-local density functional theory (NLDFT) model show different pore size S38

39 distribution for COFs synthesized from various acid-diamine salts. The long range ordering of the COF matrix has been altered with the change of the hydrogen bonding strength (hydrogen bonding distance) in acid-diamine salt. Figure S22 Pore size distribution of COFs. Pore size distributions of COFs calculated using the non-local density functional theory (NLDFT) model show different pore size distribution for COFs synthesized from various acid-diamine salts. The long range ordering of the COF matrix has been altered with the change of the hydrogen bonding strength (hydrogen bonding distance) in acid-diamine salt. S39

40 Figure S23 Pore size distribution of COFs. Pore size distributions of COFs calculated using the non-local density functional theory (NLDFT) model show different pore size distribution for COFs synthesized from various acid-diamine salts. The long range ordering of the COF matrix has been altered with the change of the hydrogen bonding strength (hydrogen bonding distance) in acid-diamine salt. S40

41 Figure S24 Pore size distribution of COFs. Pore size distributions of COFs calculated using the non-local density functional theory (NLDFT) model show different pore size distribution for COFs synthesized from various acid-diamine salts. The long range ordering of the COF matrix has been altered with the change of the hydrogen bonding strength (hydrogen bonding distance) in acid-diamine salt. S41

42 Figure S25 Pore size distribution of COFs. Pore size distributions of COFs calculated using the non-local density functional theory (NLDFT) model show different pore size distribution for COFs synthesized from various acid-diamine salts. S42

43 Section S-7: Measurement of average of hydrogen bonding distances [d avg (N amine H O acid )] in the acid-diamine salts Figure S26 Hydrogen bonding in acid-diamine salts. Average hydrogen bonding distances have been calculated by averaging the different hydrogen bonding interaction present in the salt structures. Low to high, all the hydrogen bonding interactions have been considered for better comparison. For an example, Pa-NO 2 amine has been crystallized with different acids like NBSA, PTSA, BSA, PSA and ABSA and the different hydrogen bonding distances have been shown. S43

44 We would like to mention that the N-H O bonding distance has been evaluated for all the salts considering all the N-H O interactions those are less than 2.7 Å. As an example, herein, we have represented the calculation for Pa-NO 2 -based salts. Table S10 Measurement of average N amine H O acid distance (d avg ) of hydrogen bonding distances [d avg (N amine H O acid )] in the acid-diamine salts. Sr. No. Salt Interaction D-H A N2-H2A O N2-H2B O BSA-Pa-NO 2 N2-H2C O N1-H1B O Average: N2-H2B O N2-H2C O PSA-Pa-NO 2 N2-H2A O N2-H2A O N2-H2C O Average: N4-H4B O N3-H3A O N3-H3B O NBSA- Pa-NO 2 N3-H3B O N3-H3A O N3-H3C O Average: N2-H2C O N1-H1E O PTSA- Pa-NO 2 N2-H2B O N2-H2A O Average: N1-H1A O N4-H4B O ABSA-Pa-NO 2 N2-H2A O N4-H4C O N4-H4C O Average: S44

45 Figure S27 ORTEP diagram (50% ellipsoid probability) of different acid-diamine salts. The distances represented herein are in Å unit. The intermolecular hydrogen bonding between acid and diamine controls the reactivity of the salts with the aldehyde regulating the crystallinity as well as porosity of the as-synthesized COFs. The CCDC number of each of the salts has been mentioned in brackets; PTSA-Pa-1 (628076), BSA-Pa-1 ( ), PSA- S45

46 Pa-1 ( ), NBSA-Pa-1 ( ), ABSA-Pa-1 ( ), HCl-Pa-1 (299869), Oxa- Pa-1 (614120), H 3 PO 4 -Pa-1 (261973), TFA-Pa-1 (299870), H 2 SO 4 -Pa-1 (299872), PTSA- BD-(OMe) 2 ( ), BSA-BD-(OMe) 2 ( ), ABSA-BD-(OMe) 2 ( ), NBSA- BD-(OMe) 2 ( ), HCl-BD-(OMe) 2 (636287), PTSA-BD-Me 2 ( ), HCl-BD-Me 2 (636284), NBSA-BD-Me 2 ( ), BSA-BD-(OH) 2 ( ), PSA-BD-(OH) 2 ( ), PTSA-BD-(OH) 2 ( ), NBSA-BD-(OH) 2 ( ), NBSA-Bpy ( ), PTSA-Bpy ( ), HCl-BD-Me 4 (636293). Although TpBD-Me 2 and TpPa-1 COFs appear outside of the mentioned average hydrogen bonding distance range [d avg (N amine H O acid )], they are within the range of D avg (N O) distances of Å (See below). This could justify their high surface area. Again, the lamellar structure of the salts and other factors like pk a might play the role to provide high surface area of those COFs. However, it might be possible to produce the TpBD-Me 2 COF with the higher surface area and crystallinity if the salts have the hydrogen bonding distance within the range of d avg = Å. In few cases, although NBSA based salts come within the range of suitable hydrogen bonding distance of 2.06 to 2.19 Å, they produce the COFs with less crystallinity and limited porosity (NBSA-BD-Me 4 : d avg = Å, 96 m 2 g -1 ; NBSA-Pa-Cl- NO 2 : d avg = 2.1 Å, 210 m 2 g -1 ; NBSA-Pa-Cl 2 : d avg = Å, 20 m 2 g -1 ; NBSA-Pym: d avg = Å, 60 m 2 g -1 ). This has been mentioned as an anomaly of NBSA based salts and it could be attributed to the very low reactivity of the acid that restricts them to take part in maintaining the reversibility of the reaction. Table S11 Comparison of BET Surface area of the COFs and [d avg (N amine H O acid )] of the salts. Salt Name d avg Surface area (COF) Salt Name d avg Surface area (COF) BSA-Pa-NO ABSA-BD-(OMe) PSA-Pa-NO NBSA-BD-Me NBSA-Pa-NO PTSA-BD-Me PTSA- Pa-NO HCl-BD-Me ABSA-Pa-NO BSA-Pa NBSA-Pa-Cl NBSA-Pa BSA-Pa-Cl PTSA-Pa PSA-Pa-Cl PSA-Pa PTSA-Pa-Cl ABSA-Pa PTSA-Pa HCl-Pa S46

47 BSA-Pa TFA-Pa PSA-Pa H 3 PO 4 -Pa NBSA-Pa H 2 SO 4 -Pa BSA-Pa-Cl-NO OA-Pa PSA-Pa-Cl-NO BSA-BD-Me NBSA-Pa-Cl-NO PTSA-BD-Me PTSA-Pa-Cl-NO PSA-BD-Me NBSA-Bpy NBSA-BD-Me PTSA-Bpy HCl-BD-Me NBSA-Pym BSA-BD-(OH) BSA-Pym NBSA-BD-(OH) PTSA-Pym PSA-BD-(OH) PTSA-BD-(OMe) PTSA-BD-(OH) NBSA-BD-(OMe) BSA-BD-(OMe) HCl-BD-(OMe) Figure S28 a) and b) Scattered plot of average hydrogen bonding distance (N amine H O acid ) in the salt structure vs. BET surface area of the corresponding COF. Later (b) highlights the suitable range of average hydrogen bonding that produces highest % of theoretical surface area of each type of COFs. S47

48 Section S-8: Mechanism of COF synthesis The mechanism of the imine bond formation provides the critical information of hydrogen bonding in controlling the imination reaction. The addition of aldehyde (Tp) leads to the deprotonation of the salts followed by imine bond formation via Schiff-base reaction. Then, the imine bonds undergo keto-enol tautomerism and lead to the chemically stable COF. Thus, protonation-deprotonation governs the availability of the amine thereby controlling the subsequent imination reaction. Again, the starting substrates can impart long-range order to the framework by dragging the first step of the COF formation reaction (s-cis-imine bond formation) towards the backward direction. Herein, the reversible acid-diamine salt formation reaction (protonation-deprotonation) competes with the s-cis-imination reaction which helps in sustaining the reversibility of the entire COF formation reaction, by slowing down the overall reaction. As per dynamic covalent chemistry, the higher degree of reversibility provides an opportunity for error-correction and reconstruction of the framework structure that leads to the high crystallinity (Scheme S2). Meanwhile, after deprotonation of the amine, the free acid makes the carbonyl carbons more electrophilic as it protonates the carbonyl oxygen and weakens the C=O bond. Herein, the pk a of the acid may have a little effect on the reaction. Moreover, as all the steps in imine bond formation are reversible in nature, thus the deprotonation step can (step e, Scheme S2) also be regulated by the pk a of the acids. Thus, it can be concluded that although hydrogen bonding controls the reactivity of the salts, the pk a of the acid or pk b of the base may contribute minutely to the quality of the product by affecting the reversibility of the imination reaction. In a typical example, TpPa-1 COF was synthesized from different acid-diamine salts. Acids having a range of dissociation constant (K a ) have a little effect on the porosity of the TpPa-1 COF unlike the hydrogen bonding (Table S11). The mineral acids based salts deviate from the hypothesis as they do not undergo the lamellar structure formation. Table S12 Comparison of the pk a of the acids vs. the BET surface area of the COFs. Acid-amine salt pk a (acid) a BET surface area (m 2 /g) H 3 PO 4 -Pa TFA-Pa ABSA-Pa PSA-Pa-1 > S48

49 NBSA-Pa BSA-Pa PTSA-Pa HCl-Pa H 2 SO 4 -Pa OXA a corresponds to Guthrie, J. P. Can. J. Chem.1978, 56, Scheme S2 Proposed mechanism of imine bond formation of salts. The mechanism has been represented concerning amine only instead of diamine to keep the schematic representation simple. In order to understand the role of hydrogen bonding, we have synthesized PTSA-Pa-Cl 2 salt based TpPa-Cl 2 COF (d avg = Å) in different time duration of 24 h, 48 h and 72 h (Table S13 and Figure S29). But, the change in time duration of the reaction doesn t alter the COF s property significantly. The reason can be attributed to the mechanism of crystallization. The efficient bond formation is not sufficient to obtain ordered materials. On the other hand, the longer reaction time only helps the effective bond formation without contributing much toward the reversibility of the reaction. S49

50 Table S13 Surface area analysis of TpPa-Cl 2 COF (PTSA-Pa-Cl 2 ) at different time duration. COF BET surface area (m 2 /g) (24 h) BET surface area (m 2 /g) (48 h) BET surface area (m 2 /g) (72 h) TpPa-Cl 2 COF (PTSA-Pa-Cl 2 ) Figure S29 Comparison of a) BET surface area and b) PXRD pattern of TpPa-Cl 2 COF at different time interval. S50

51 Section S-9: Measurement of average N amine O acid distances (D avg ) The heavy atom distances [D avg (N amine O acid ) N -atom of the amine to the O -atom of the acid] of the salts further supports our principle of porosity prediction. The plot of S BET vs. D avg also supports our finding on the role of hydrogen bonding in resulting highly crystalline and porous COFs. To correlate the structure-property relation (acid-diamine salts nature vs. crystallinity and porosity of COFs), we have chosen moderate to high crystalline COFs. It has been observed that the salts having D avg (N O) distances of Å result in highly crystalline COFs (Figure S30 and Table S14). The salt Pa-Cl 2 presents average N O distance of 2.830, and Å, when it has been crystallized with BSA, PSA and PTSA, respectively. When the salts have further been transformed into TpPa-Cl 2 COF, it exhibits variable surface area of 989, 632 and 359 m 2 g -1. The high surface area can be attributed to the suitable hydrogen bonding distances that are within the above-mentioned hydrogen bonding range of 2.78 to 2.91 Å. Similarly, PTSA-BD-(OMe) 2 (D avg = Å) produces highly crystalline TpBD-(OMe) 2 COF with surface area 1365 m 2 g -1 whereas BSA- BD-(OMe) 2 (D avg = Å) results in the low crystalline and less porous COF (S BET = 210 m 2 g -1 ). Figure S30 Scattered plot of hydrogen bonding distance (N O) in the salt structure vs. BET surface area of the corresponding COF. The moderate surface area can be associated with the suitable hydrogen bonding distance that is on the borderline of the as mentioned hydrogen bonding range. S51

52 Table S14 Comparison of BET Surface area of the COFs and D avg of the salts. Surface area Acid-diamine D avg (Å) of the COF salt (m 2 g -1 ) BSA-Pa-NO Surface area Acid-diamine D avg (Å) of the COF salt (m 2 g -1 ) PTSA-BD- (OMe) PSA-Pa-NO BSA-BD-(OMe) PTSA- Pa-NO PTSA-BD-Me BSA-Pa-Cl BSA-Pa PSA-Pa-Cl PTSA-Pa PTSA-Pa-Cl PSA-Pa PTSA-Pa BSA-BD-Me BSA-Pa PTSA-BD-Me PSA-Pa PSA-BD-Me BSA-BD- (OH) 2 PSA-BD- (OH) 2 BSA-Pa-Cl- NO PSA-Pa-Cl-NO PTSA-Pa-Cl- NO BSA-Pym PTSA-Pym S52

53 Section S-10: Pawley refinement and fractional atomic coordinates Figure S31 Pawley refinement for TpPa-Cl 2. Pawley refinement indicates good agreement between the simulated and experimental PXRD patterns. Table S15. Fractional atomic coordinates for the unit cell of TpPa-Cl 2 COF synthesized from BSA-Pa-Cl 2 salt TpPa-Cl 2 in eclipsed model (Space group 'P6/m') a = 20.5 Å, b = 20.5 Å, c = 3.5 Å; α = 90, β = 90, γ = 120 Atom O1 N1 C1 x y z S53

54 C2 C3 C4 C5 C6 Cl H1 H2 H Figure S32 Pawley refinement for TpPa-Cl-NO 2. Pawley refinement indicates good agreement between the simulated and experimental PXRD patterns. S54

55 Table S16. Fractional atomic coordinates for the unit cell of TpPa-Cl-NO 2 COF synthesized from PTSA- Pa-Cl-NO 2 salt TpPa-Cl-NO 2 in eclipsed model (Space group 'P1') a = 21.9 Å, b = 21.9 Å, c = 3.2 Å; α = 90, β = 90, γ = C1 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C2 C20 C21 C22 C23 C24 C25 C26 C27 C S55

56 C29 C3 C30 C31 C32 C33 C34 C35 C36 C4 C5 C6 C7 C8 C9 H1 H10 H11 H12 H13 H14 H15 H16 H17 H18 H S56

57 H2 H20 H21 H3 H4 H5 H6 H7 H8 H9 N1 N2 N3 N4 N5 N6 N7 N8 N9 O1 O10 O11 O12 O2 O3 O S57

58 O5 O6 O7 O8 O Figure S33 Pawley refinement of TpBD-Me 4. Pawley refinement indicates good agreement between the simulated and experimental PXRD patterns. S58

59 Table S17. Fractional atomic coordinates for the unit cell of TpBD-Me 4 COF synthesized from PTSA- BD-Me 4 salt TpBD-Me 4 in eclipsed model (Space group 'P1') a = 33.8 Å, b = 33.5 Å, c = 3.0 Å; α = 90, β = 90, γ = N C C C C C C C C H C H H H O C N C C C C C C C C H C H H H O C N C C C C C C S59

60 C C H C H H H O C N C C C C C C C C H C H H H O C N C C C C C C C C H C H H H O C N C C C C C C S60

61 C C H C H H H O C C C C C C C H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H S61

62 H H H Figure S34 Pawley refinement for TpPym. Pawley refinement indicates the agreement between the simulated and experimental PXRD patterns. Table S18. Fractional atomic coordinates for the unit cell of TpPym COF synthesized from PTSA- Pym salt TpPym in eclipsed model (Space group 'P1') a = 10.7 Å, b = 10.7 Å, c = 3.2 Å; α = 90, β = 90, γ = C1 C2 C3 C4 C5 C S62

63 O7 C8 O9 C10 O11 C12 N13 N14 N15 C16 N17 C18 C19 C20 N21 H22 H23 H24 H25 H26 H27 H S63

64 Section S-11: TG analyses Figure S35 TG analyses. TGA data of as-synthesized TpPa-Cl 2 (from BSA-Pa-Cl 2 ) (a), TpPym (from PTSA-Pym) (b), TpPa-Cl-NO 2 (from PTSA-Pa-Cl-NO 2 ) (c), and TpBD-Me 4 (d), showing the high thermal stability (minimum up to 350 C) under N 2 atmosphere. S64

65 Section S-12: SEM and TEM analyses Figure S36 SEM analyses of COFs. a-d, SEM images shows the sheet-like morphology of TpPa-Cl 2 (PSA) (5 μm) (a), TpPa-Cl-NO 2 (PTSA) (5 μm) (b), TpPym (PTSA) (10 μm) (c), TpBD-Me 4 (PTSA) (10 μm) (d). The names of the respective acids have been mentioned in brackets, which have been used to produce the acid-diamine salts. The numerical values have been mentioned in the bracket to represent the scale bars for those respective images. S65

66 Figure S37 TEM analyses of COFs. TEM images of TpPa-Cl 2 (PSA) (50 nm) (a), TpPa- Cl-NO 2 (PTSA) (200 nm) (b), TpPym (PTSA) (100 nm) (c), TpBD-Me 4 (PTSA) (50 nm) (d), showing the layered morphology of the COFs. (The numerical values mentioned in the bracket to represent the scale bars for those respective images). S66

67 Section S-13: 13 C CP-MAS spectra Figure S38 13 C CP-MAS spectra. Solid state 13 C CP-MAS spectrum of TpBD-Me 4, TpPa- Cl 2 TpPa-Cl-NO 2 and TpPym showing the characteristic carbon peaks corresponding to the respective COFs. S67