fig2

Figure 2. Structure and characterization of TANB-Py-COF. (A) Chemical structure of TANB-Py-COF and TAPB-Py-COF; (B) Graphic view of one layer of TANB-Py-COF simulated by Material Studio. (azure, pink, C; blue, N; white, H); (C) PXRD patterns of TANB-Py-COF; (D) PXRD patterns of TANB-Py-COF before and after treatment in triethylamine, 3M NaOH, HOAc, 3M HCl and boiling water for 3 days; (E) Fourier transform infrared (FT-IR) spectroscopy spectra of TANB-Py-COF, TANB and Py; (F)¹³C-CP/TOSS NMR spectrum of TANB-Py-COF; (G) Nitrogen adsorption and desorption isotherm at 77 K of TANB-Py-COF; (H) Pore size distribution of TANB-Py-COF; (I) Thermogravimetric analysis of TANB-Py-COF. COF: Covalent organic framework; PXRD: powder X-ray diffraction; ¹³C-CP/TOSS: ¹³C cross-polarization/total sideband suppression; NMR: nuclear magnetic resonance.