Quantifying the nitrogen effect on CO capture using isoporous network polymers.

The impact of nitrogen atoms on CO binding was evaluated for two isostructural porous bisimidazole-linked polymers (BILPs), which serendipitously had identical surface areas and pore size distributions, a very rare observation. The two structures differ only in the core of the trialdehyde component, the nitrogen atom (BILP-19) versus benzene ring (BILP-5). Such a slight difference, however, has brought about a stronger CO capture capacity of BILP-19 and hence increased CO/N separation capability.