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Imine‐Linked Covalent Organic Cage Porous Crystals for CO 2 Adsorption
Author(s) -
Gajula Ramesh Kumar,
Kishor Rupak,
Prakash. M. Jaya
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201903781
Subject(s) - adsorption , imine , covalent bond , crystallography , chemistry , powder diffraction , molecule , materials science , stereochemistry , organic chemistry , catalysis
In this study, covalent organic cages (COC‐MI, COC‐PI and COC‐PA) with covalently imine linked molecules were developed for CO 2 adsorption. By varying the organic linkers ( iso ‐phthalaldehyde to para ‐phthalaldehyde) tuned the structure and extrinsic porosity such as specific surface area of the organic cages was demonstrated. Additionally, COC‐PI (3.8 cm 3 /g to 5.7 cm 3 /g) and COC‐PA (0.43 cm 3 /g to 0.48 cm 3 /g) showed the significantly enhancement in CO 2 adsorption capacity with increase in temperature from 273 K to 298 K at 1 bar. On the other hand, COC‐MI (1.17 cm 3 /g to 1.1 cm 3 /g) cage showed the significant reduction in CO 2 adsorption capacity with increase in temperature from 273 K to 298 K at 1 bar. These unusual enhancements of CO 2 adsorption capacity within COC‐PI and COC‐PA is elucidated by powder X‐ray diffraction (PXRD), and it is shown that cooperative diffusion and induced crystal lattice expansion in these molecular crystals can enhance the CO 2 adsorption capacity. Computational modelling on the COC cages with CO 2 reveals the higher binding energy and rigidity at the C=N group during intermolecular interactions enhances the overall CO 2 adsorption capacity in the bulk.