Fig. 5
From: Sub-stoichiometric 2D covalent organic frameworks from tri- and tetratopic linkers
Characterization of PT2B- and PY2B-COFs. a FT-IR characterization of PT2B- and PY2B-COFs. The inset shows the presence of νC=N(stretch). b 13C ssNMR spectra with corresponding assignments. The unassigned signals correspond to the pyrene moiety and the phenyl rings. 15N ssNMR depicting the absence of free amine functionalities in PT2B- and PY2B-COFs is shown on the right as an inset. c PXRD patterns of PT2B- and PY2B-COFs with corresponding Rietveld refinements (magenta) showing good fits to the experimental data (black) with minimal differences. The turquiose traces show the difference between the experimental data and the refinement. The corresponding Miller indices of the identifiable reflections are shown as well. d Argon sorption isotherms of PT2B- and PY2B-COFs at 87 K. Filled and open symbols represent the adsorption and the desorption branches, respectively
